51364749-5-Load-Control

DMA Load Contro

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The WCDMA system is a self interference system. As the load of the WCDMA system increases, the interference rises. A relatively high interference may affect the coverage and Quality of Service (QoS) of established services. Therefore, capacity, coverage and QoS of the WCDMA system are mutually affected. The purpose of load control is to maximize the system capacity while ensuring coverage and QoS.

(§) Objectives Upon completion of this course, you will be able to:

D Know load control principles

a Know load control realization methods in WCDMA system

D Know load control parameters in WCDMA system

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@ Contents 1. Load Control Overview

2. Load Control Algorithms

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© Contents 1. Load Control Overview

1.1 Load Control Alaorithms Overview

1.2 Load Measurement

1.3 Priorities Involved in Load Control

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Load Definition • Load: the occupancy of capacity

• Two kinds of capacity in WCDMA system

• Hard capacity

. Cell DL OVSF Code v A

• NodeB Transport resource I > '

• NodeB processing capability (NodeB credit)

n Soft capacity

. Cell Power (UL and DL) ; 1

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1. Power .include DL transmitting power of cell and increased UL interference (RTWP). 2. DL OVSF code of a cell 3. DL and UL NodeB processing capability which is defined by NodeB credit. 4. lub transmission bandwidth of a NodeB The power resource is related to the mobility, distribution of the UE and also effected by the radio conditions. Therefore, for a fixed power resource, the numbers of service can be supported is not a fix result. We believe the UL and DL power resources are soft.

WCDMA network load can be defined by 4 factors:

The Objectives of Load Control • Keeping system stable

• Maximizing system capacity while ensuring coverage and QoS

• Realize different priorities for different service and different user

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WCDMA network load can be defined by 4 factors: 1,Power .include DL transmitting power of cell and increased UL interference (RTWP). 2,DL OVSF code of a cell 3.DL and UL NodeB processing capability which is defined by NodeB credit. 4,lub transmission bandwidth of a NodeB The power resource is related to the mobility, distribution of the UE and also effected by the radio conditions. Therefore, for a fixed power resource, the numbers of service can be supported is not a fix result. We believe the UL and DL power resources are soft.

Load Control Algorithms

• The load control algorithms are applied to the different UE access phases as follows: , -^ K'

+ rrr •-pyC tAC > LDB CAC J W% Time OLC

" % > 1, Before UE access 2. During UE access ? After UE access

*~ PUC: Potential User Control CAC: Call Admission Control IAC: Intelligent Admission Control LDB : Intra-frequency Load Balancing LDR: Load Reshuffling OLC: Overload Control

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The load control algorithms are applied to the different UE access phases as follows: Before UE access: Potential User Control (PUC) During UE access: Intelligent Access Control (IAC) and Call Admission Control (CAC) After UE access: intra-frequency Load Balancing (LDB), Load Reshuffling (LDR), and Overload Control (OLC)

Load Control Algorithms Load control algorithm in the WCDMA system

Load control algorithm

NodeB

i i

RNC t t I

Iub

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The load control algorithms are built into the RNC. The input of load control comes from the RNC and measurement information of the NodeB. RNC can calculate hard resource load, that is OVSF ,NodeB credit, Iub occupancy. The soft load need the NodeB reporting.

© Contents 1 . Load Control Overview

1.1 Load Control Algorithms Overview


13 Priorities Involved in Load Control

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Soft Load Measurement J U The major measurement objects of the load measurement > ,*&&

/

UL Load

DL Load

Uplink Received Total Wideband Power (RTWP)

Received scheduled Enhanced Dedicated Channel (E-DCH) power share (RSEPS)

E-DCH Provided Bit Rate

TCP \)U

Non-HSPATCP r * j iAr^ * L

HSDPA PBR

HSDPA GBP

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The soft load control algorithms use load measurement values in the uplink and the downlink. A common Load Measurement (LDM) algorithm is required to control load measurement in the uplink and the downlink. The NodeB and the RNC perform measurements and filtering in accordance with the parameter settings. The statistics obtained after the measurements and filtering serve as the data input for the load control algorithms. The major measurement objects of the LDM are as follows: •Uplink Received Total Wideband Power (RTWP) •Received scheduled Enhanced Dedicated Channel (E-DCH) power share (RSEPS) •E-DCH Provided Bit Rate oDownlink Transmitted Carrier Power (TCP) •TCP of all codes not used for High Speed Physical Downlink Shared Channel (HS-PDSCH), High Speed Shared Control Channel , (Non-HSPA TCP) •Provided Bit Rate on HS-DSCH (PBR) •HS-DSCH required power, also called Guaranteed Bit Rate (GBR) required power (GBP)

Load Measurement procedure

Sam;:: L1/L3 filtering

ISmoothed filtering

State and load information processing

-*•! PUC

Smoothed filtering

State and load information processing -*- CAC

Smoothed { filtering |

Smoothed I filtering

Slate and load information processing

Stale and toad information processing

tt -+-

LDR

OLC

Smoothed filtering

State and toad information processing M LDB

NodeB j C s i d o „ • « _ _ — L _ _ — a * .

IX, Jp(«) = i = 2 _

p N

N : the size of the smooth window

Pn : the reported measurement value

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The NodeB measures the major measurement quantities and then obtains original measurement values. After layer 3 filtering on the NodeB side, the NodeB reports the cell measurement values to the RNC. The RNC performs smooth filtering on the measurement values reported from the NodeB and then obtains the measurement values, which further serve as data input for the load control algorithms.

Filtering on the NodeB Side

Parameters

A Layer 1 filtering

8

+ Layer 3 filtering

c I I I I

A is the sampling value of the measurement. B is the measurement value after layer 1 filtering. C is the measurement value after layer 3 filtering ,which is the reported measurement value

Layer 1 filtering is not standardized by protocols and it depends on vendor equipment. Layer 3 filtering is standardized. The filtering effect is controlled by a higher layer.

The NodeB periodically reports each measurement quantity to the RNC. The following table lists the reporting intervals for the measurement quantities.

Measurement

RTWP

RSEPS

TCP

Non-HSDPA power

GBP

HS-DSCH PBR

E-DCH PBR

Reporting Interval ( Unit: ms )

1000

1000

200

200

1000

100

100

Smooth Window Filtering on the RNC Side After the RNC receives the measurement report, it filters the measurement value with the smooth window. Assuming that the reported measurement value is Qn and that the size of the smooth window is N, the filtered measurement value is :

W - l

Q = ^ ^ , N

Delay susceptibilities of PUC, CAC, LDR, and OLC to common measurement are different. The LDM algorithm must apply different smooth filter coefficients and measurement periods to those algorithms; thus, they can get expected filtered values.

Algorithm

PUC

LDB

LDR

CAC

OLC

default Value

32

32

25

3

25

Smooth window for GBP for all related algorithms are the same and the default setting is 1

© Contents 1 . Load Control Overview

1.1 Load Control Algorithms Overview


1.3 Priorities Involved in Load Control

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Priority • The service of user with

control algorithms first

• Three kinds of priorities

a User Priority

D RAB Integrate Priority

n User Integrate Priority

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User Priority: mainly applying to provide different QoS for different users. Eg., setting different GBR according to the user priority for BE service. No consideration about the service. RAB Integrate Priority: Priority of a service, related to the service type, and the user priority of the user. User Integrate Priority: Only used for multi-RAB user ,it is a temporary priority of an ongoing-service user.

User Priority • There are three levels of user priority ^1

a gold (high), silver (middle) and copper (low) user

User priority

Uplink

Downlink

Gold

128kbps

128kbps

Silver

64kbps

64kbps

Copper

32kbps

32kbps

C~^)

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In CN HLR, we can set ARP (Allocation Retention Priority ).During service setup, CN sends ARP to RNC .Based on the mapping relation( configured in RNC), RNC can identify the user's priority, gold, silver or copper one. The user priority affect GBR of a BE service in RAN, Iub transmission management and so on.

B ^ allocationOrRetentioriPriority

priorityLeveLOxc (12) pre-emptionCapability:shall-not-trigger-pre-emption (0) pre-emptionVulnerability:not-pre-emptable (0) queuingAllowediqueueing-allowed (1)

User Priority # The mapping relation between user priority and ARP .

(Allocation/Retention Priority) is configured in RNC by SET USERPRIORITY

n An example:

ARP

User Priority

1 2 3 4

Gold

5 6 7 8 9

Silver

10 11 12 13 14 15

Copper

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The user priority mapping can be configured in RNC by SET USERPRIORITY ARP 15 is always the lowest priority and it cannot be configured. It corresponds to copper. If ARP is not received in messages from the Iu interface, the user priority is regarded as copper.

RAB Integrate Priority • RAB Integrate Priority is mainly used in

algorithms

• RAB Integrate Priority are set according

a ARP

D Traffic Class

n THP (for interactive service only)

a HSPAorDCH

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RAB Integrate Priority is mainly used in load control algorithms. The values of RAB Integrate Priority are set according to the Integrate Priority Configured Reference parameter as follows: If Integrate Priority Configured Reference is set to Traffic Class, the integrate priority abides by the following rules:

Traffic classes: conversational -> streaming -> interactive -> background => Services of the same class: Priority based on Allocation/Retention Priority (ARP) values, that is, ARP1 -> ARP2 -> ARP3 -> ... -> ARP14 => Only for the interactive service of the same ARP value: priority based on Traffic Handling Priority (THP, defined in CN , sent to RNC during service setup), that is, THP1 -> THP2 -> THP3 -> ... -> THP14 => Services of the same ARP, class and THP (only for interactive services): High Speed Packet Access (HSPA) or Dedicated Channel (DCH) service preferred depending on the value of the Indicator of Carrier Type Priority parameter.

If Integrate Priority Configured Reference is set to ARP, the integrate priority abides by the following rules:

ARP1 -> ARP2 -> ARP3 -> ... -> ARP14 => Traffic classes: conversational -> streaming -> interactive -> background => Only for the interactive service of the same ARP value: priority based on Traffic Handling Priority (THP), that is, THP1 -> THP2 -> THP3 -> ... -> THP14 => Services of the same ARP, class and THP (only for interactive services): HSPA or DCH service preferred depending on the value of the Indicator of Carrier Type Priority parameter. Integrate Priority Configured Reference and Indicator of Carrier Type Priority are set by SET USERPRIORITY . By default Integrate Priority Configured Reference is set to ARP Indicator of Carrier Type Priority is set to NONE, that means HSPA and DCH services have the same priority.

ARP and THP are carried in the RAB ASSIGNMENT REQUEST message, and they are not configurable on the RNC LMT.

An Example for RAB Integrate Priority

Services attribution in the cell

Service ID

A B

C D

ARP

1

1

2 2

Traffic Class

Interactive

Interactive

Conversational

Background

Bear type DCH

HSDPA

DCH

DCH

Based on ARP, HSPA priority is higher

Service ID

B A

C

D

ARP

1 1

2

2

Traffic Class

Interactive

Interactive

Conversational

Background

Bear type

HSDPA

DCH DCH

DCH

Based on Traffic Class, HSPA priority is higher

Service ID

C

B

A

D

Traffic Class

Conversational

Interactive

Interactive

Background

ARP

2

1

1 2

Bear type

DCH

HSDPA

DCH

DCH


This example shows the RAB Integrate Priority calculation in 2 different conditions

User Integrate Priority • When the user has only one RAB, User

same as the RAB integrate priority

integrate priority is the

* For multiple RAB users, the integrate priority of the

on the service of the highest priority

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When the user has one RAB, User integrate priority is the same as the service of the RAB integrate priority; For multiple RAB users, the integrate priority of the user is based on the service of the highest priority. User integrate priority is used in user-specific load control. For example, the selection of R99 users during preemption, the selection of users during inter-frequency load handover for LDR, and the selection of users during switching BE services to CCH are performed according to the user integrate priority.

Key parameters of Priority • Integrate Priority Configured Reference

a Parameter ID: PRIORITYREFERENCE

• The default value of this parameter is ARP

• Indicator of Carrier Type Priority

D Parameter ID: CARRIERTYPEPRIORIND

• The default value of this parameter is NONE

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Integrate Priority Configured Reference Parameter ID: PRIORITYREFERENCE Value range: ARP, Traffic Class Content: This parameter is used to set the criterion by which the priority is first sorted. The default value of this parameter is ARP Set this parameter through SET USERPRIORITY

Indicator of Carrier Type Priority Parameter ID: CARRIERTYPEPRIORIND Value range: NONE, DCH, HSPA Content: This parameter is used to decide which carrier (DCH or HSPA) takes precedence when ARP and Traffic Class are identical. When this parameter is set to NONE, the bearing priority of services on the DCH is the same as that of HSPA

. services. The default value of this parameter is NONE, Set this parameter through SET USERPRIORITY

^ J Contents 2. Load Control Algorithms

2.1 PUC (Potential User Control)

2.2 LDB (Intra-Frequency Load Balancing)

2.3 CAC {Call Admission Control)

2.4 IAC (Intelligent Admission Control)

2.5 LDR (Load Reshuffling)

2.6 OLC (Overload Control)

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PUC Principles ir * The Potential User Control (PUC) algorithm controls the inter-.J

s** )

.frequency cell reselection of the potential UE, and prevents UE

from camping on a heavily loaded cell.

• Potential UE :

D IDLE Mode UE

Q CELL-FACH UE, CELL-PCH UE, URA-PCH UE

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The function of PUC is to balance traffic load among inter-frequency cells. By modifying cell selection and reselection parameters and broadcasting them through system information, PUC leads UEs to cell with light load. The UE may be in idle mode, Cell_FACH state, Cell _PCH state, UfRA_PCH state

PUC Load Judgment UL/DL load

i

Load level. threshold

Load level di\ threshold

Heavy Normal

ISI on

son

t t t t time RNC periodic check

<o Load level division hysteresis


Cell load for PUC is of three states: heavy, normal, and light The RNC periodically monitors the downlink load of the cell and compares the measurement results with the configured thresholds Load level division threshold 1 and Load level division threshold 2, that is, load level division upper and lower thresholds. If the cell load is higher than the ioad level division upper threshold plus the Load level division hysteresis, the cell load is considered heavy. If the cell load is lower than the load level division lower threshold minus the Load level division hysteresis, the cell load is considered light. Otherwise the cell load is considered normal

Sy\ 5^'\ c\

v-v*

- > T

PUC Procedure

Heavy?

Light?

Normal?

Threshold Every 200ms

Cell TCP

System information

R N C Parameters N o d e B U E

Every 30 minutes

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The parameters related to cell selection and cell reselection are Qoffset1(s,n) (load level offset), Qoffset2(s,n) (load level offset), and Sintersearch (start threshold for inter-frequency cell reselection). The NodeB periodically reports the total TCP of the cell, and the PUC periodically triggers the following activities: Assessing the cell load level based on the total TCP Configuring Sintersearch, Qoffset1(s,n), and Qoffset2(s,n) based on the cell load level PUC can Modify inter-frequency cell reselection parameters based on the load: 1 s • • **intersearch •

when the load of a cell is "Heavy", PUC will increase Sintersearch

when the load of a cell is "Light", PUC will decrease Sjntersearch

2- Qoffset1

when the load of current cell is "Heavy" and neighbor is "Non heavy", PUC will decrease 5ffset when the load of current cell is "Non heavy" and neighbor is "Heavy", PUC will increase

Ôffset

Ôffset

Updating the parameters of system information SIB3 and SIB11

Load of Current Cell

Light

Normal

Heavy

Sintersearch

S'intersearch = Sintersearch + Sintersearch offset 1

S'intersearch = Sintersearch

S'intersearch = Sintersearch + Sintersearch offset 2

Change of Sintersearch

\

—

/

—: indicates that the parameter value remains unchanged. / : indicates that the parameter value increases. \ : indicates that the parameter value decreases.

Neighboring Cell Load

Non-Heavy

Non-Heavy

Heavy

Heavy

Current Cell Load

Non-Heavy

Heavy

Non-Heavy

Heavy

Q'offsetl

Q'offsetl = Qoffsetl

Q'offsetl = Qoffsetl + Qoffsetl offset 1

Q'offsetl = Qoffsetl + Qoffsetl offset 2

Q'offsetl = Qoffsetl

Change of Q'offsetl

—

\

/

-*

Qoffset2

Q'offsetZ = Qoffset2

Qoffset2 = Qoffset2 + Qoffset2 offset 1

Q'offset2 = Qoffset2 + Qoffset2 offset 2

Q'offset2 = Qoffset2

Change of Q'offse

i

\

/

-*

PUC Principles

Freql

System Inf SIB3.11

LHard to trigger reselection 2.Easy to camp on the cell

Increase the POTENTIAL load System Int SIB3.11

Freq2 1. Easy to trigger reselection 2.Easy to select light load J-Inter-freq neighbor Cell ^

Decrease the POTENTIAL load

, - ^ Heavy load

18' System Inf

SIB3.11 Idle state CCH state

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Based on the characteristics of inter-frequency cell selection and reselection. Sintersearch

When this value is increased by the serving cell, the UE starts inter-frequency cell reselection ahead of schedule.

When this value is decreased by the serving cell, the UE delays inter-frequency cell reselection.

Qoffsetl (s,n): applies to R (reselection) rule with CPICH RSCP When this value is increased by the serving cell, the UE has a lower probability of

selecting a neighboring cell. When this value is decreased by the serving cell, the UE has a higher probability

of selecting a neighboring cell.

Qoffset2(s,n): applies to R (reselection) rule with CPICH Ec/10 When this value is increased by the serving cell, the UE has a lower probability of

selecting a neighboring cell. When this value is decreased by the serving cell, the UE has a higher probability

of selecting a neighboring cell.

Key parameters PUC • Ceil LDC algorithm switch

n Parameter ID: NBMLDCALGOSWITCH PUC

• The default value of this parameter is Off

« Load level division threshold 1 (Heavy)

a Parameter ID: SPUCHEAVY

a The default value of this parameter is 70(70%)

• Load level division threshold 2 (Light)

a Parameter ID: SPUCLIGHT

n The default value of this parameter is 45(45%)

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Cell LDC algorithm switch Parameter ID: NBMLDCALGOSWITCH PUC Value range: OFF, ON Content: This parameter is used to enable or disable the PUC algorithm.. The default value of this parameter is OFF Set this parameter through ADD CELLALGOSWITCH /MOD CELLALGOSWITCH

Load level division threshold 1 (Heavy) Parameter ID: SPUCHEAVY Value range: 0 to 100 Content: This parameter is one of the thresholds used to assess cell load level and to decide whether the cell load level is heavy or not. The default value of this parameter is 70%, Set this parameter through ADD CELLPUC / MOD CELLPUC

Load level division threshold 2 (Light) Parameter ID: SPUCLIGHT Value range: 0 to 100 Content: This parameter is one of the thresholds used to assess cell load level and to decide whether the cell load level is heavy or not. The default value of this parameter is 45%, Set this parameter through ADD CELLPUC / MOD CELLPUC

Key parameters PUC • Load level division hysteresis

a Parameter ID: SPUCHYST

n The default value of this parameter is 5 (5%)

• PUC period timer length

D Parameter ID: PUCPERIODTIMERLEN

n The default value of this parameter is 1800(s)

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Load level division hysteresis Parameter ID: SPUCHYST Value range: OFF, ON Content: This parameter specifies the hysteresis used during cell load level assessment to avoid unnecessary ping-pong effect of a cell between two load levels due to a little load change. The default value of this parameter is 5 (5%) Set this parameter through ADD CELLPUC / MOD CELLPUC

PUC period timer length Parameter ID: PUCPERIODTIMERLEN Value range: 6 to 86400 s Content: This parameter specifies the period of potential user control. The higher the parameter is set, the longer the period to trigger the PUC is. The default value of this parameter is 1800(s) Set this parameter through SET LDCPERIOD

Key parameters PUC • Sintersearch offset 1

a Parameter ID: OFFSINTERLIGHT

a The default value of this parameter is - 2 (-4dB)

• Sintersearch offset 2

a Parameter ID: OFFSINTERHEAVY

• The default value of this parameter is 2 (4dB)

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Sintersearch offset 1 Parameter ID: OFFSINTERLIGHT Value range: -10 to 10 ,step:2dB Content: This parameter defines the offset of Sintersearch when the center cell load level is "Light". It is strongly recommended that this parameter be set to a value not higher than 0. The default value of this parameter is -2 (-4dB) Set this parameter through ADD CELLPUC / MOP CELLPUC

Sintersearch offset 2 Parameter ID: OFFSINTERHEAVY Value range: -10 to 10 ,step:2dB Content: This parameter defines the offset of Sintersearch when the center cell load level is "Heavy". It is strongly recommended that this parameter be set to a value not lower than 0. The default value of this parameter is 2 (4dB) Set this parameter through ADD CELLPUC / MOD CELLPUC

Key parameters PUC * Qoffsetl offset 1 (For RSCP)

a Parameter ID: 0FFQ0FFSET1 LIGHT

n The default value of this parameter is - 4 (-8dB)

• Qoffsetl offset 2 (For RSCP)

a Parameter ID: OFFQOFFSET1 HEAVY

o The default value of this parameter is 4 (8dB)

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Qoffsetl offset 1 Parameter ID: OFFQOFFSET1 LIGHT Value range: -10 to 10 ,step:2dB Content: This parameter defines the offset of Qoffsetl (RSCP) when the current cell has heavy load and the neighboring cell has light or normal load. To enable the UE to select a neighboring cell with relatively light load, it is strongly recommended that this parameter be set to a value not higher than 0. The default value of this parameter is -4 (-8dB) Set this parameter through ADD CELLPUC/MOD CELLPUC

Qoffsetl offset 2 Parameter ID: OFFQOFFSET1 HEAVY Value range: -10 to 10 ,step:2dB Content: This parameter defines the offset of Qoffsetl (RSCP) when the load of a neighboring cell is heavier than that of the center cell. To enable the UE to select a neighboring cell with relatively light load, it is strongly recommended that this parameter be set to a value not lower than 0. The default value of this parameter is 4 (8dB) Set this parameter through ADD CELLPUC/MOD CELLPUC

Key parameters PUC • Qoffset2 offset 1 (For Ec/No)

a Parameter ID: 0FFQ0FFSET2LIGHT

a The default value of this parameter is - 4 (-8dB)

• Qoffset2 offset 2 (For Ec/No)

a Parameter ID: OFFQOFFSET2HEAVY

n The default value of this parameter is 4 (8dB)

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Qoffsetl offset 1 Parameter ID: OFFQOFFSET1 LIGHT Value range: -10 to 10 ,step:2dB Content: This parameter defines the offset of Qoffsetl (RSCP) when the current cell has heavy load and the neighboring cell has light or normal load. To enable the UE to select a neighboring cell with relatively light load, it is strongly recommended that this parameter be set to a value not higher than 0. The default value of this parameter is -4 (-8dB) Set this parameter through ADD CELLPUC/MOD CELLPUC

Qoffsetl offset 2 Parameter ID: OFFQOFFSET2HEAVY Value range: -10 to 10 ,step:2dB Content: This parameter defines the offset of Qoffset2 (EcNo) when the load of a neighboring cell is heavier than that of the center cell. To enable the UE to select a neighboring cell with relatively light load, it is strongly recommended that this parameter be set to a value not lower than 0. The default value of this parameter is 4 (8dB) Set this parameter through ADD CELLPUC / MOD CELLPUC

Contents 2. Load Control Algorithms



23 CAC (Call Admission Control)




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Intra-Frequency Load Balancing * Intra-frequency Load Balancing (LDB) is performed to adjust the

coverage areas of cells by modifying PCPICH power

• LDB affect UEs in all states

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Intra-frequency Load Balancing (LDB) is performed to adjust the coverage areas of cells according to the measured values of cell downlink power load. RNC checks the load of cells periodically and adjusts the transmit power of the P-CPICH in the associated cells based on the cell load. When the load of a cell increases, the cell reduces its coverage to lighten its load. When the load of a cell decreases, the cell extends its coverage so that some traffic is off-loaded from its neighboring cells to it. Reduction of the pilot power will make the UEs at the edge of the cell handed over to neighboring cells, especially to those with a relatively light load and with relatively high pilot power. After that, the downlink load of the cell is lightened accordingly.

LDB Procedure Threshold

• 3

Normal? *"---! Modify cell PCPICH I *»

RNC power NodeB

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^ ^ wk Handover or — ^ r H r .1 » i f

fjp» Cell Reselection Updated PCPICH

POWER UE

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The NodeB periodically reports the total TCP of the cell, and the LDB periodically triggers the following activities: Assessing the cell load level based on the total TCP If the downlink load of a cell is higher than the value of the Cell overload threshold, it is an indication that the cell is heavily loaded. In this case, the transmit power of the P-CPICH needs to be reduced by a step, which is defined by the Pilot power adjustment step parameter. However, if the current transmit power is equal to the value of the Min transmit power of PCPICH parameter, no adjustment is performed. If the downlink load of a cell is lower than the value of the Cell underload threshold, it is an indication that the cell has sufficient remaining capacity for more load. In this case, the transmit power of the P-CPICH increases by a step, which is defined by the Pilot power adjustment step parameter, to help to lighten the load of neighboring cells. However, if the current transmit power is equal to the value of the Max transmit power of PCPICH parameter, no adjustment is performed.

Key parameters LDB • Cell LDC algorithm switch

a Parameter ID: NBMLdcAlgoSwitch LDB

• The default value of this parameter is Off

• Intra-frequency LDB period timer length

n Parameter ID: IntraFreqLdbPeriodTimerLen

p The default value of this parameter is 1800 (s)

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Cell LDC algorithm switch Parameter ID: NBMLdcAlgoSwitch LDB Value range: OFF, ON Content: This parameter is used to enable or disable the LDB algorithm.. The default value of this parameter is OFF Set this parameter through ADD CELLALGOSWITCH / MOD CELLALGOSWITCH

intra-frequency LDB period timer length Parameter ID: IntraFreqLdbPeriodTimerLen Value range: 0 to 86400 Content: This parameter specifies the length of the intra-frequency LDB period. The default value of this parameter is 1800 (s) Set this parameter through SET LPCPERIOD

Key parameters LDB • Cell overload threshold (Heavy)

n Parameter ID: CellOverrunThd

a The default value of this parameter is 90(90%)

• Cell underload threshold (Light)

a Parameter ID: CellUnderrunThd

• The default value of this parameter is 30(30%)

• Pilo t power adjustmen t s tep

a Parameter ID: PCPICHPowerPace

n The default value of this parameter is 2 (0.2dB)


•

MHP $ % HUAWEI

Cell overload threshold Parameter ID: CellOverrunThd

Value range: 0 to 100 Content: If the downlink load of a cell exceeds this threshold, the algorithm can decrease the pilot transmit power of the cell so as to extend the capacity of the whole system. The default value of this parameter is 90%, Set this parameter through ADD CELLLDB / MOO CELLLDB

Cell underload threshold Parameter ID: CellUnderrunThd Value range: 0 to 100 Content: If the downlink load of a cell is lower than this threshold, the algorithm can increase the pilot transmit power of the cell so as to share the load of other cells. The default value of this parameter is 30%, Set this parameter through ADD CELLLDB / MOD CELLLDB

Pilot power adjustment step Parameter ID: PCPICHPowerPace Value range: 0 to 10 , Step 0.1 dB Content: This parameter defines the step for the adjustment to the pilot power. The default value of this parameter is 2, 0.2dB Set this parameter through ADD CELLLDB / MOD CELLLDB

Key parameters LDB • Max transmit power of PCPICH

n Parameter ID: MaxPCPICHPower

D The default value of this parameter is 346 (34.6dBm)

• Min transmit power of PCPICH

a Parameter ID: MinPCPICHPower

a The default value of this parameter is 313 (31.3dBm)

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page39 | P i | HUAWEI

Max transmit power of PCPICH Parameter ID: MaxPCPICHPower Value range: -100 to 500 .Step 0.1 dB Content: This parameter defines the maximum transmit power of the P-CPICH in a cell. This parameter has to be set according to the actual system environment, that is, for example, cell coverage (radius) and geographical environment. If the maximum transmit power of the P-CPICH is set too low, the cell coverage decreases. When a certain proportion of soft handover area is ensured, any more increase in the pilot power achieves no improvement on the performance of the downlink coverage. The default value of this parameter is 346 (34.6dBm) Set this parameter through ADD PCPICH / MOP PCPICHPWR

Min transmit power of PCPICH Parameter ID: MinPCPICHPower Value range: -100 to 500 Content: This parameter defines the minimum transmit power of the P-CPICH in a cell. This parameter has to be set according to the actual system environment, that is, for example, (radius) and geographical environment. If the minimum transmit power of the P-CPICH is set too low, the cell coverage will be affected. The parameter has to be set under the condition that a certain proportion of soft handover area is ensured or the occurrence of coverage hole can be prevented. The default value of this parameter is 313 (31.3dBm) Set this parameter through ADD PCPICH / MOD PCPICHPWR

@ Contents 2. Load Control Algorithms



2.3 CAC (Call Admission Control)




Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page40 4fH HUAWEI

Why we need CAC? • WCDMA

admitted,

* If a cell is dropped

9 We must

Planning

is an interference limited system, after a the system load will be increased

new call is

high loaded, a new call will cause ongoing user

keep the coverage planned by the Radio


Network

| H | HUAWEI

CAC is needed under such scenarios: 1. RRC connection setup request 2. RAB setup and Bandwidth increasing 3. Handover 4. Rate reconfiguration (Reconfigure RB)

Flow chart of CAC Admiss ion reques t

r e s

Code a d m i s s i o n v

Y e s

l-'ower aiJiTH'-.-.iiji'r--'

Ye- ,

NodeB c r e d i t admiss ion?

iub r e s o u r c e admiss ion?

S P A u s e r numoe admiss ion?

Resou rce admiss ion p a s s e d -•e-L-auic-i-:- .:•>.;--;r: :-..•;,. on den ted

Copyright © 2009 Huawei Technologies Co., Ltd. Alt rights reserved. Page42 HUAWEI

The admission decision is based on: Cell available code resource: managed in RNC Cell available power resource, that is DL/UL load : measured in NodeB

• NodeB credits, that is, NodeB processing resource state, Channel Elements .managed in RNC Available Iub transport layer resource, that is, Iub transmission bandwidth: managed in RNC HSPA user number (only for HSPA service)

Algorithm Switch of CAC Admission control Switches can be set on RNC LMT:

* Power CAC a Uplink CAC algorithm switch

o Downlink CAC algorithm switch

* NodeB Credit CAC D CAC algorithm switch : CacSwitch

a Cell CAC algorithm switch: CRD_ADCTRL

• HSDPA user number CAC D CAC algorithm switch :HSDPA_UU_ADCTRL

* HSUPA user number CAC n CAC algorithm switch: HSUPA_UU_ADCTRL

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page43 | l § HUAWEI

Except the mandatory code and Iub resource admission control, the admission control based on power and NodeB credit,HSDPA User Number can be disabled through the LMT command:

Power CAC can be switched off by ADD CELLALGOSWITCH / MOD CELLALGOSWITCH Uplink CAC algorithm switch (NBMULCACALGOSELSWITCH ) specifies the algorithm used

for power admission in the uplink. Downlink CAC algorithm switch (NBMDLCACALGOSELSWITCH) specifies the algorithm

used for power admission in the downlink.

NodeB Credit CAC can be switched off bv SET CACALGOSWITCH or ADD CELLALGOSWITCH / MOD CELLALGOSWITCH

CAC algorithm switch (CacSwitch) specifies the NodeB level credit CAC algorithm Cell CAC algorithm switch (CRD_ADCTRL) specifies the Cell level credit CAC algorithm.

HSDPA user number CAC switched off by ADD CELLALGOSWITCH / MOD CELLALGOSWITCH

HSDPA_UU_ADCTRL specifies whether to enable or disable the HSDPA admission control algorithm.

HSUPA user number CAC switched off by ADD CELLALGOSWITCH / MOD CELLALGOSWITCH

HSUPA_UU_ADCTRL specifies whether to enable or disable the HSUPA admission control algorithm

CAC Based on Code Resource • Code Resource CAC functions in:

n RRC connection setup

• Handover

a R99 services setup

Note: RRC connection setup and Handover have higher priority

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page44 | § # HUAWEI

When a new service attempts to access the network, code resource admission is mandatory.

1. For RRC connection setup requests, the code resource admission is successful if the current remaining code resource is enough for the RRC connection.

2. For handover services, the code resource admission is successful if the current remaining code resource is enough for the service.

3. For R99 services setup and Rate Reconfiguration, the RNC has to ensure that the remaining code does not exceed the configurable threshold after admission.

4. For HSDPA services, the reserved codes are shared by all HSDPA services. Therefore, the code resource admission is not needed.

So the RRC connection setup and Handover has higher priority to access a cell

CAC Based on Power Resource

• UL and DL Power Resource CAC functions in:

n RRC connection setup

n Handover

a Services setup

Note: RRC connection setup and Handover have higher priority

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page45 # # HUAWEI

The UL CAC and DL CAC are independent. The basic principle of Power CAC is: RNC predict the cell power load after the access. If the load will be higher than a threshold, the admission is failed. So, by setting different threshold for different access services, we can realize different priorities. Power admission is used in all the access scenarios, except for:

•For Intra-frequency handover request, uplink power admission is not need. •For rate downsizing, RNC accept the request directly without admission.

Power CAC Algorithms • Algorithm 1: based on UL/DL load measurement and load

prediction (RTWP and TCP) . r ^ J i " J W t i fcU «*•» *} fo*>

« Algorithm 2: based on Equivalent Number of User (ENU) / > y * V

• Algorithm 3: loose call admission control algorithm

Copyright © 2009 Huawei Technologies Co., Ltd. Ail rights reserved. Page46 flHI H U A W E I

Huawei provide 3 Power CAC Algorithms Algorithm 1: power resource admission decision based on power or interference. Depending on the current cell load (uplink load factor and downlink transmitted carrier power) and the access request, the RNC determines whether the cell load will exceed the threshold upon admitting a new call. If yes, the RNC rejects the request. If not, the RNC accepts the request. Algorithm 2: power resource admission decision based on the number of equivalent users.Based on Huawei testing and experience, The 12.2 kbit/s AMR traffic is used to calculate the Equivalent Number of Users (ENU) of all other services in UL and DL. The 12.2 kbit/s AMR traffic's ENU is assumed to be 1. Depending on the current number of equivalent users and the access request in UL and DL, the RNC determines whether the number of equivalent users will exceed the threshold upon admitting a new call. If yes, the RNC rejects the request. If not, the RNC accepts the request. Algorithm 3: power resource admission decision based on power or interference, but with the estimated load increment always set to O.Depending on the current cell load (uplink load factor and downlink TCP) and the access request, the RNC determines whether the cell load will exceed the threshold, with the estimated load increment set to 0. If yes, the RNC rejects the request. If not, the RNC accepts the request.

n fc iTT (LV*I X

Basic principle of Uplink CAC Algorithm 1

C Admission request j

i Get current RTWP, and calculate the

current load factor 1

Get the traffic characteristic, and estimate the increment of load factor

X Calculate the predicted load factor

Smaller than the threshold?

admitted rejected

c End of UL CAC

- % t = l - .V

RTWP

"^VL predicted ~ VuL + A /7 + T]CCH

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page47 f t HUAWEI

Pn is uplink receive background noise. ' ' JAXMTHT The procedure for uplink power resource decision is as follows: 1. The RNC obtains the uplink RTWP of the cell, and calculate the current uplink load

factor. 2. The RNC calculates the uplink load increment A n. UL based on the service request. 3. The RNC uses the formula n UL,predicted= n UL + A n UL to forecast the uplink load

factor. 4. By comparing the forecasted uplink load factor a UL.predicted with the corresponding

threshold ,the RNC decides whether to accept the access request or not.

For HSUPA service access, the RSEPS and PBR will be considered when calculating the cell load.

i

^ : • j ^ J *AA A

-y K^ A>

A

Basic principle of Downlink CAC Algorithml Downlink admission control request

i f Get measurement TCP and calculate

the current downlink load factor

V calculate the increment of downlink

load due to the request

v Get the predicted downlink factor

1 compare the predicted downlink

factor with the admission threshold

TCP

< ^« = i r

-+ lot,?**** -Vm*^Hm +%!_**

Copyright © 2009 Huawei Technoiogies Co., Ltd. AU rights reserved. Page48 n H U A W G 1

The procedure for downlink power resource decision is as follows:

1. The RNC obtains the cell downlink TCP and calculates the downlink load factor i j DL by dividing the maximum downlink transmit power Pmax by this TCP.

2. The RNC calculates the downlink load increment A P based on the service request and the current load.

3. The RNC forecasts the downlink load factor. 4. By comparing the downlink load factor with the corresponding threshold (DL threshold

of Conv AMR service, DL threshold of Conv non_AMR service, DL threshold of other services, DL Handover access threshold), the RNC decides whether to accept the access request or not.

For HSDPA service access, the GBP and PBR should be considered.

1

\

Basic principle of CAC A C Admission request J

i Get current total ENU

I Get the traffic characteristic, and estimate the increment of ENU

1 Calculate the predicted ENU

•

admitted

C op>

O

Smaller than the ^threshold? .

* End of UL/DL CAC

right © 2009 Huawei Technolog

' '

Igorithm 2

—ENU t M l (N) = Y.ENU, >- ^ *N. i t

v, new

+-ENUtotal (N +1) = ENUtolal (N) + ENU„m

H ENULoad = ENUtotal(N+l)/ENUaax

rejected

o es Co., Ltd. All rights re served. Page49 ^ ^ H U A W E I

The procedure for ENU resource decision is as follows: 1. The RNC obtains the total ENU of all exist users ENUtotal. 2. The RNC get the ENU of the new incoming user ENUnew. 3. The RNC forecast the ENU load. 4. By comparing the forecasted ENU load with the corresponding threshold (the same

threshold as power resource), the RNC decides whether to accept the access request or not.

The ENUmax can be set by LMT, the ENUnew and ENUi is determined by Huawei algorithm, there is an example in next slide.

Power CAC for RRC connection Setup • For the RRC connection request is, tolerance principles are

applied :

D Emergency call, Detach , Registration

• Direct Admission

n RRC connection request for other reasons

m UL/ DL OLC Trigger threshold Admission

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. PageSO w w H U A W E I

To ensure that the RRC connection request is not denied by mistake, tolerance principles are applied.

The admission decision is made for the following reasons of the RRC connection request: 1. For the RRC connection request for the reasons of emergency call, detach or

registration, direct admission is used ,that is no limitation. 2. For the RRC connection request for other reasons, UL/DL OLC Trigger

threshold is used for admission. By default, the OLC trigger threshold is relatively high (DL/UL 95%), which make the RRC connections are easily set up.

UL Power CAC for R99 Cell (Algorithm 1) •' i

• For? R9£ DCH RAB Setup, The RNC uses the following formula to predict the uplink load factor:

VuL_ predicted = WuL "*" **tfuL +rluL-CCH

a Where the

VuL RTWP • By comparing the predicted uplink load factor n ULiPredicted with the

corresponding threshold ,the RNC decides whether to accept the access request or not

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page51 wPIB ' H U A W E I

The threshold for Conv AMR service , Conv non_AMR service , Other R99 services Handover are set independently, which provide different priorities.

Normally, Other R99 services < Conv non_AMR service services < Conv AMR service < Handover

The uplink load increment A nUL is determined by: 1. The Eb/No of the new incoming call 2. The uplink load increment is proportional to the value of Eb/No. 3. UL neighbor interference factor 4. Active Factor of the new incoming call

DL Power CAC for R99 Cell (Algorithml)

• For R99 DCH RAB Setup, The RNC uses the following formula to predict the downlink load factor:

T?DL_ predicted ~ ^DL + ^DL + ^DL-CCH

a Where the TCP . _A?7 0 i

? 7 z > i = T T - ^DL-—

« By comparing the predicted downlink load factor ri DLiPredicted with the corresponding threshold ,the RNC decides whether to accept the access request or not

Copyright © 2009 Huawei Technologies Co., Ltd. AH rights reserved. PageS2 W W H U A W E I

The threshold for Conv AMR service , Conv non_AMR service , Other R99 services , Handover are set independently, which provide different priorities.

Normally, Other R99 services < Conv non_AMR service services < Conv AMR service < Handover

The downlink load increment A n DL is determined by: 1. The Eb/No of the new incoming call 2. Non-orthogonality factor 3. Current transmission carrier power 4. Active Factor of the new incoming call

UL Power CAC for HSPA Cell (Algorithml) • The power increment of an HSUPA service is related to Ec/No, GBR

requirement, neighboring interference factor, active factor of the service. The formula of UL power CAC for HSUPA is similar to that for R99

• After BSEES^measurement is introduced, the UL RTWP is divided into two parts:

Q Controllable part • The UL interference generated by E-DCH scheduling services belong to the

controllable part

• Uncontrollable part

Copyright © 2009 Huawei Technologies Co., Ltd. AN rights reserved. P«ge53 ; »P» HUAWEI

RSEPS: Received scheduled E-DCH power share

UL Power CAC for HSPA Cell (Algorithml) « E-DCH scheduling service consists of following two types:

a TypeA: all UEs for which this cell is the serving E-DCH cell

• The uplink load generated by TypeA E-DCH scheduling service is defined as follows: RSEPS

VuL-EDCH-S — n-ru-p

a TypeB: all UEs for which this cell is

NOT the serving EDCH-cell • The uplink load generated by TypeB E-DCH scheduling service

is defined by nUL,EDCH,f.

which is fixed to zero

• The Uplink uncontrollable load

Is defined as follows: •7« = 1-

RTWP

VUL,nor,-Ctrl ~ ÛL ^lui^DCH,s 7luL,EDCH f

T

%K I

% • JL_, r F

* i

EDCH Scfteduted

(TyJKJ A)

NiM'-Setving Cos £OCH Scheduled

(Typ»B>

f 1 1

SSSPS I ******* ' RTWP t

Jfci,

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page54 H H HUAWEI

UL Power CAC for HSPA Cell (Algorithml)

• UL Power CAC for R99 service in HSPA cell

n Uncontollable interference must be kept within a given range. The purpose is to ensure the stability of system and to prevent non-scheduling services and DCH services from seizing the resources of HSUPA services

UuL,mn~ctrl + ^'HuL + tfuL^ch + W HS-DPCCH < ^thd

WUL + ^'HuL + tfuL.^ch + tfHS-DPCCH < tfthd-total

n RNC admits R99 services if formula 1 and 2 are fulfilled

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. PageSS |f)§• HUAWEI

n thd_tota| is the UL total power threshold of the current cell n thd is the cell UL admission threshold for specific type of service, that is UL threshold of Conv

AMR service, UL threshold of Conv non_AMR service, UL threshold of other services or UL handover access service threshold

UL Power CAC for HSPA Cell (Algorithml) « UL Power CAC for HSUPA Scheduling Services and HSUPA Non-Scheduling Services

V PBR, > TML • £ GBR,

T, PBR, > Thdi • Y GBR,

:::::y ]T ?Bgi>7iidsr v GS/C,

4 1m + -^ %i + 'fol.cch + V HS-DPCCH "''• QtM-Mel.-

5. ^VL.mtt-ctrl + « ^Rt + lui.uh + H'HS-DPCCH ' ' ^ z w g cases

• Formula 1,2 or 3 is fulfilled

n Formula 4 is fulfilled

RNC admits HSUPA Non-scheduling service in either of the following cases

a Formula 1,2 or 3 is fulfilled

a Formula 4 and 5 are fulfilled

Copyright © 2009 Huawei Technologies Co., Ltd. AH rights reserved. Page56 HUAWEI

ThdL is the Low priority HSUPA user PBR threshold of the current cell ThdE is the Equal priority HSUPA user PBR threshold of the current cell ThdGE is the High priority HSUPA user PBR threshold of the current cell

PE t

0

R, P 3R2 PBR,

; 3 4

i ) « „

P 8k >Th **..'

5 6

I < ;HH,

7

SPI

*

8

lew user

z Sflr-^-f,,,

PBR, >TM - ]T c,Hli.

9 10 11 12 13 14 15

z I'Bl ; > n <*»•' z e«R

n HS.DPCCH 's ^ e v a l u e °f the UL HS-DPCCH reserve factor parameter, which defines the factor of UL HS-DPCCH resource reserved ntnd is the cell UL admission threshold for specific type of service, that is UL threshold of Conv

AMR service, UL threshold of Conv non_AMR service, UL threshold of other services or UL handover access service threshold

DL Power CAC for HSPA Cell (Algorithml) • DL Power incremental estimation for DCH RAB in HSPA cell is

similar to the DCH RAB in R99 cell

• DL Power incremental estimation for HSDPA RAB A PDL is made based on GBR, Ec/No, Non-orthogonality factor

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. PaqfiS? MRS' HUAWEI

DL Power CAC for HSPA Cell (Algorithml)

* DL power CAC for R99 service in HSPA cell

P x. p 4. \P < P . ThA \ i ' xm-htpa • ' «fc_re '-" 111. ~ um ' ""««-.*v>>H~t;itv

p 4. AP < P . 7/W 2, ' umi T "-1' ML -" * max ' '"*»«/-<:»"„>

3_ * * # » % « . * * " ^ 0 * _ | « I T W H P I +*hmpa_*!>•**nm. h^J + ^"lX. - "mix ' *'K't,/ijl-iar,

• RNC admits R99 service (i.e. DCH RAB) in either of the following

situations:

• Formula 1 and 2 are fulfilled

• Formula 1 and 3 are fulfilled

: ::;:;:: :: ' :'" " :: ::: :. • Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page58 flp H U A W E I

Pnon_hspa is the current non-HSDPA power Pcch.res is the power reserved for the common channel Pmax is the cell maximum transmit power Thd^n^spg^g,. is the cell DL admission threshold for different types of service, that is DL threshold for Conv AMR service, DL threshold for Conv non-AMR service, DL threshold for other service or DL handover access threshold Ptotal is the current downlink transmitted carrier power Thdtotal-cac is the threshold of cell DL total power. It is defined by the DL total power threshold parameter GBP is power requirement for GBR pnsupa-resis t h e P°wer reserved for HSUPA downlink control channels (E-AGCH/E-RGCH/E-HICH) F'max-nspa is the maximum available power for HSPA. Its value is associated with the HSDPA power allocation mode.

DL Power CAC for HSPA Cell (Algorithml) . DL power CAC for HSDPA RAB in HSPA cell

PBR^lzThd,^. _ YCBR„a, , 1

, GBP + PU +AP,„ <P ,

RNC admits the HSDPA streaming service in any of the following situations:

• Formula 1 is fulfilled

• Formulas 3 and 4 are fulfilled

a Formulas 3 and 5 are fulfilled

RNC admits the HSDPA BE service in any of the following situations:

a Formula 2 is fulfilled



Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page59 3# H U A W E I

PBRstrm is the provided bit rate of all existing streaming services Thdhsd fr is the admission threshold for streaming PBR decision. It is defined by the Hsdpa streaming PBR threshold parameter PBRbe is the provided bit rate of all existing BE services Thdhsdg fe is the admission threshold for BE PBR decision. It is defined by the Hsdpa best effort PBR threshold parameter GBR is the power requirement for GBR PhsuPa-resis t h e power reserved for HSUPA downlink control channels (E-AGCH/E-RGCH/E-HICH) pmax-hspa's ™e maximum available power for HSPA. Its value is associated with the HSDPA power allocation mode. Ptotai'\s the current downlink transmitted carrier power Pmax is the cell maximum transmitted power Thdtotal_cac is the threshold of cell DL total power, which is defined by the DL total power threshold parameter Pccn-res,s ê P o w e r reserved for the common channels Pnon-hspa ' s t h e current non-HSDPA power

DL Power CAC for HSPA Cell (Algorithml)

• DL power CAC for HSUPA control channels in HSPA cell

n The power of downlink control channels (E-AGCH/E-RGCH/E-HICH) are reserved by DL HSUPA reserved factor. Therefore, the power admission for these channels is NOT needed

Copyright @ 2009 Huawei Technologies Co., Ltd. AH rights reserved. Page60 t S P w H U A t A r E I

Power CAC for Algorithm2 For R99 and HSPA RAB, The RNC uses the following formula to predict the uplink ENU load factor:

u (ENUtotal + ENUnew)/ENUmax

By comparing the forecasted ENU load with the corresponding threshold ,the RNC decides whether to accept the access request or not

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page61 # « HUAWEI

ENUtotal is the total ENU of all existing users. ENUnew is ENU of the new incoming user. ENUmax is the configured maximum ENU (UL total equivalent user number or DL total nonhsdpa equivalent user number). The threshold for Algorithm2 are the same with Algorithml,for Conv AMR service , Conv non_AMR service , Other R99 services , Handover, HSDPA are set independently:

Service Type

UL DCH/HSUPA

DLDCH

HSDPA

Admission Threshold

UL threshold of Conv AMR service UL threshold of Conv non_AMR service UL threshold of other services UL Handover access threshold

DL threshold of Conv AMR service DL threshold of Conv non_AMR service DL threshold of other services DL Handover access threshold

DL total power threshold

Typically ENU (equivalent number of users) for different services (with activity factor to be 100%)

•Service*'

3.4 kbit/s SIGo

13.6 kbit's SIG+=

3.4 + 12.2 kbit/s*-1

3.4 + 8 kbit/s (PS)+=

3.4 + 16 kbit's (PS)«=

3.4 + 32 kbit's (PS>*=

3.4 + 64 kbit/s (PS)+3

3.4 +128 kbit/s (PS)*

3.4 + 144 kbit/s (PS)*

3.4 + 256 kbit's (PS)+

3.4 + 384 kbit/s (PS)*

ENU*'

Uplink for DCH+

0.44*1

1.1 I*1

1.44+'

1.35+'

1.62*=

2.15*'

3.45+=

5.78*3

6.41*3

10.18P

14.27*=

Downlink for DCH*

0.42*5

111*'

1.42*3

1.04+'

1.25*3

2.19+3

3.25+3

5.93+3

6.61+=

10.49+3

15.52*3

HSDPA

0.28*'

0.74+3

- » 3

0.78+3

l.H-3

1.70*3

2.79*3

4.92*'

5.46+=

9.36*=

14.17-

HSUPA '

1.76*-'

1.89+3

-*»'

2.26+=

2.37+-

2.60+3 "• •

3.14*3

4.67*1

4.87+=

6.61+3

9.36+=

Service Type

UL DCH/HSUPA

DLDCH

HSDPA

Admission Threshold

UL threshold of Conv AMR service UL threshold of Conv non_AMR service UL threshold of other services UL Handover access threshold

DL threshold of Conv AMR service DL threshold of Conv non_AMR service DL threshold of other services DL Handover access threshold


Key parameters * UL threshold of Conv AMR service

a Parameter ID: UlNonCtrlThdForAMR

n The default value of this parameter is 75%

• UL threshold of Conv non_AMR service

a Parameter ID: UlNonCtrlThdForNonAMR

a The default value of this parameter is 75%

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page63 | f t§ HUAWEI

UL threshold of Conv AMR service Parameter ID: UlNonCtrlThdForAMR Value range: 0 to 100% Content: The uplink threshold for the AMR conversational service is used for the uplink admission of AMR conversational service users. The threshold is shared by algorithm 1, algorithm 2 and algorithm 3. The default value of this parameter is 75% Set this parameter through ADD CELLCAC / MOD CELLCAC

UL threshold of Conv non_AMR service Parameter ID: UlNonCtrlThdForNonAMR Value range: 0 to 100% Content: The downlink threshold for the AMR conversational service is used for the downlink admission of AMR conversational service users. The threshold is shared by algorithm 1, algorithm 2 and algorithm 3. The default value of this parameter is 75% Set this parameter through ADD CELLCAC / MOD CELLCAC

Key parameters » UL threshold of other services

a Parameter ID: UlNonCtrlThdForOther


• UL Handover access threshold

D Parameter ID: UlNonCtrlThdForHo


Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page64 H H HUAWEI

UL threshold of other services Parameter ID: UlNonCtrlThdForOther Value range: 0 to 100 % Content: This parameter is the uplink threshold for services other than the conversational service. It is used for uplink admission of other services. The threshold is shared by algorithm 1, algorithm 2 and algorithm 3. The default value of this parameter is 60% Set this parameter through ADD CELLCAC / MOD CELLCAC

UL Handover access threshold Parameter ID: UlNonCtrlThdForHo Value range: 0 to 100 % Content: The uplink handover threshold is used for uplink admission of handover users. The parameter is useful only to uplink inter-frequency handovers. Do not make the admission decision in the uplink soft handover. The threshold is shared by algorithm 1, algorithm 2 and algorithm 3. The default value of this parameter is 80% Set this parameter through ADD CELLCAC / MOD CELLCAC

Key parameters • DL threshold of Conv AMR service

a Parameter ID: DLCONVAMRTHD


• DL threshold of Conv non_AMR service

a Parameter ID: DlConvNonAMRThd


Copyright ® 2009 Huawei Technologies Co., Ltd. All rights reserved. Page6S H i HUAWEI

DL threshold of Conv AMR service Parameter ID: DLCONVAMRTHD Value range: 0 to 100 % Content: The downlink threshold for the AMR conversational service is used for the downlink admission of AMR conversational service users. The threshold is shared by algorithm 1, algorithm 2 and algorithm 3. The default value of this parameter is 80% Set this parameter through ADD CELLCAC / MOD CELLCAC

DL threshold of Conv non__AMR service Parameter ID: DlConvNonAMRThd Value range: 0 to 100 % Content: The downlink threshold for the non-AMR conversational service is used for the downlink admission of non-AMR conversational service users. The threshold is shared by algorithm 1, algorithm 2 and algorithm 3. The default value of this parameter is 80% Set this parameter through ADD CELLCAC / MOD CELLCAC

Key parameters • DL threshold of other services

a Parameter ID: DLOTHERTHD

D The default value of this parameter is 75%

• DL Handover access threshold

n Parameter ID: DLHOTHD


Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page66 0$ HUAWEI

DL threshold of other services Parameter ID: DLOTHERTHD Value range: 0 to 100 % Content: This parameter is the downlink threshold for services other than the conversational service. It is used for downlink admission of users of other services. The threshold is shared by algorithm 1, algorithm 2 and algorithm 3. The default value of this parameter is 75% Set this parameter through ADD CELLCAC/MOD CELLCAC

DL Handover access threshold Parameter ID: DLHOTHD Value range: 0 to 100 % Content: The downlink handover threshold is used for downlink admission of handover users. The threshold is shared by algorithm 1, algorithm 2 and algorithm 3. The default value of this parameter is 85% Set this parameter through ADD CELLCAC / MOD CELLCAC

Key parameters • DL total power threshold

a Parameter ID: DLCELLTOTALTHD


• Hsdpa streaming PBR threshold

• Parameter ID: HSDPASTRMPBRTHD

• The default value of this parameter is 70%

* Hsdpa best effort PBR threshold

a Parameter ID: HSDPABEPBRTHD


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DL total power threshold Parameter ID: DLCELLTOTALTHD Value range: 0 to 100 % Content: This parameter specifies the total downlink power threshold of the cell. The default value of this parameter is 90% Set this parameter through ADD CELLCAC / MOD CELLCAC

Hsdpa streaming PBR threshold Parameter ID: HSDPASTRMPBRTHD Value range: 0 to 100% Content: This parameter specifies the average throughput admission threshold of the HSDPA streaming traffic. The default value of this parameter is 70% Set this parameter through ADD CELLCAC / MOD CELLCAC

Hsdpa streaming PBR threshold Parameter ID:: HSDPABEPBRTHD Vaiue range: 0 to 100 % Content: This parameter specifies the average throughput admission threshold of the HSDPA best effort traffic. -The default value of this parameter is 70% Set this parameter through ADD CELLCAC / MOD CELLCAC

Key parameters • UL total equivalent user number

a Parameter ID: ULTOTALEQUSERNUM

D The default value of this parameter is 80

• DL total equivalent user number

a Parameter ID: DLTOTALEQUSERNUM

n The default value of this parameter is 80

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UL total equivalent user number Parameter ID: ULTOTALEQUSERNUM Value range: 1 to 200 Content: When algorithm 2 is used, this parameter defines the total equivalent number of users corresponding to the 100% uplink load. The default value of this parameter is 80 Set this parameter through ADD CELLCAC/MOD CELLCAC

DL total equivalent user number Parameter ID: DLTOTALEQUSERNUM Value range: 1 to 200 Content: When algorithm 2 is used, this parameter defines the total equivalent number of users corresponding to the 100% downlink load. The default value of this parameter is 80 Set this parameter through ADD CELLCAC / MOD CELLCAC

CAC Based on NodeB Credit Resource • When a new service accesses the network, NodeB credit

resource admission is optional

• The principles of NodeB credit admission control are similar to

those of power resource admission control

• When a new service tries to access the network, the credit

resource admission CAC functions in :

a RRC connection setup

n Handover service

a Services setup

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CE stands for NodeB credit on RNC side and for Channel Element on NodeB side. It is used to measure the channel demodulation capability of the NodeBs The resource of one 12.2kbps voice service, including 3.4kbps signaling on the DCCH, consumed in baseband is defined as one CE. If there is 3.4kbps signaling on the DCCH, but no voice channel, one CE is consumed.The credit resource are divided into several resource pools. Each resource pool is shared by a local cell. According to the common and dedicated channels capacity consumption laws, as well as the addition, removal, and reconfiguration of the common and dedicated channels, the Controlling RNC (CRNC) debits the amount of the credit resource consumed from or credits the amount to the Capacity Credit of the local cell group (and local cell, if any) based on the spreading factor. the UL Capacity Credit and DL Capacity Credit are separate, so the CAC is performed in the UL and DL, respectively.

For an RRC connection setup request, the credit resource admission is successful if the current remaining credit resource is sufficient for the RRC connection. For a handover service, the credit resource admission is successful if the current remaining credit resource is sufficient for the service. For other services, the RNC has to ensure that the remaining credit does not exceed the configurable thresholds after admission of the new services. There is no capacity consumption law for HS-DSCH in 3GPP TS 25.433, so certain credits are reserved for HSDPA RAB, and credit admission for HSDPA is not needed. UL Capacity Credit and DL Capacity Credit are separate, the credit resource admission is implemented in the UL and DL, respectively.

CAC Based on NodeB Credit Resource • For DCH service, MBR is used to calculate the NodeB Credit

based on spreading factor.

• The total NodeB Credit Resource of a local cell is depend on the configuration.

'• ' :•:>:•.•: .• "" ' • :- :-•'••.: ••\:'\fi:::::.::'' ::.:•;. : "' '. ••' :: ;•;••: • "" "" ;,-----:- ••:-•-••••• Copyright © 2009 Huawei Technologies Co., Ltd. AH rights reserved. Page70 V i r H U A W 6 1

Direction

DL

UL

DL

UL

DL

UL

DL

UL

DL

UL

DL

UL

DL

UL

DL

UL

Spreading Factor

256

256

128

64

128

64

32

16

64

32

32

16

16

8

8

4

Corresponding Credits Consumed

1

2

1

2

1

2

2

6

1

3

2

6

4

10

8

20

I Typical Traffic Class ;

3.4 kbit/s SRB

13.6 kbit/s SRB

12.2 kbit/s AMR

64 kbit/s VP

32 kbps PS

64 kbit/s PS

128 kbit/s PS

384 kbit/s PS

CAC Based on NodeB Credit Resource

• For HSUPA service, the rate used to calculate the spreading factor is MBR

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page71 2. HUAW61 ...;.... . . . .' : . ' ' _•• . ...... .. ; '.

• D i r e c t i o n *

um U L P

U L f

tJl>

UL*'

UL«3

UL*»

UL*>

Ul>3

UL*3

UL*'

U L P

UL*>

Rate (IcMt/s)*'

8-P

16*3

32-3

64*?

128*3

144.3

256*3

384f

608-3

1450«'

2048 . '

2890*3

5760*3

S p r e a d i n g Factor *!

6 4 ^

64-3

32-3

32*-1

16*3

16*-1

8-'

4*3

4*3

2SF2-3

2SF2*'

2SF2+2SF4*--

2SF2+2SF4*?

N u m l j e r o f CEs C o n s u m e d *?

w Q 1.5*3

1.5*=

3*3

3»=

s*--10*3

10*3

32-3

32«3

48*3

48*J

C o r r e s p o n d i n g C r e d i t s C o n s u m e d * '

2*? *

2*

3*> 3*3

6s

6*3

10*= 1

20*3

20*3

64*3

64*3

96*3

96*3 <

-

Key parameters • UI Handover Credit Reserved SF

a Parameter ID: UlHoCeResvSf

D The default value of this parameter is SF16

• Dl Handover Credit and Code Reserved SF

a Parameter ID: DlHoCeCodeResvSf

• The default value of this parameter is SF32

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UI Handover Credit Reserved SF Parameter ID: UlHoCeResvSf Value range: SF4, SF8, SF16, SF32, SF64, SF128, SF256, SFOFF Content: The spreading factor specified by this parameter is used to define the uplink credit resource reserved for handover services. SFOFF means that none of resources are reserved for handover services. If the remaining uplink resource cannot fulfill the requirement for the reserved resource after the admission of a new service, the service is rejected. The default value of this parameter is SF16 Set this parameter through ADD CELLCAC / MOD CELLCAC

Dl Handover Credit and Code Reserved SF Parameter ID: DlHoCeCodeResvSf Value range: SF4, SF8, SF16, SF32, SF64, SF128, SF256, SFOFF Content: The spreading factor specified by this parameter is used to define the downlink credit and channelized code resources reserved for handover services. SFOFF means that none of the resources is reserved for handover. If the remaining downlink resource cannot fulfill the requirement for the reserved resource after the access of a new service, the service is rejected. The default value of this parameter is SF32 Set this parameter through ADD CELLCAC / MOD CELLCAC

CAC Based on Iub Interface Resource « The CAC of the Iub transmission resources is similar

• Admission Control is used to determine whether the Tub

resources are enough to accept a new access request

• It functions in:

o RRC connection setup

n Handover

a Services RAB setup

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A user accessing the network from a path should go through the admission of the path, resource group, and physical port in turn. The user that passes all the admission can be successfully admitted by the transport layer. Path means AAL2 PATH, IP PATH The physical ports correspond to IMA, UNI, FRAATM, NCOPT, ETHER, PPP, and MLPPP. The priority of the 2 types of access follows : Handover >RRC connection setup and Services RAB setup

CAC Based on Iub Interface Resource

• Iub Overbooking a The Iub overbooking feature considers the statistic multiplexing of

service activities and multiple users

• Admit more users, increases the resource utilization on the Iub interface.

; : ; ; • ; ; ............ • . ... ...... Copyright ® 2009 Huawei Technologies Co., Ltd. All rights reserved. Page74 <§P£§' H U A W E I

The Iub overbooking feature considers the statistic multiplexing of service activities and multiple users. Through the admission of more users, Iub overbooking increases the resource utilization on the Iub interface. If the RNC allocates the maximum bandwidth to the subscriber when a service is established, a large proportion of the Iub transmission bandwidth is unused. For example, downloading a 50 KB page takes only about one second, but reading this page needs dozens of seconds. Thus, over 90% of the Iub transmission bandwidth is not used. To save the Iub transmission bandwidth for operator use, Huawei provides the Iub overbooking function, which applies an admission control mechanism to access the service.


• Iub Overbooking n CS voice services

• Service rate: 12.2 kbit/s

. SID

n PS interactive and background services

• Download time

• Reading time

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page7S $% HUAWEI

The UMTS supports four traffic classes: conversational, streaming, interactive, and background. The transmission rate varies with the traffic class as follows: For Circuit Switched (CS) conversational services, the channel transmits voice signals at a certain rate (for example, 12.2 kbit/s) during a conversation and only transmits Silence Descriptors (SIDs) at intervals when there is no conversation. For Packet Switched (PS) interactive and background services, such as web browsing, there is data transmitted during data downloading. After a web page has been downloaded, and when the user is reading the page, however, there is very little data to transfer.


• Iub Overbooking a CS voice services

• Activity Factor

o PS interactive and background services

. GBR * Activity Factor

a MML

SET DEFAULTFACTORTABLE

SET USERGBR

.•- ..•:--:-:-~- • ' • ' .:.-•••••:•••.• •---,•-;•,• ̂ :•.-••• ..,•..,.,..,.,,.•,.,,.,.,,,.,,,...•,,.:,...,,.• . ...... ... Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page76 4 P w HUAtWVGI

Use SET DEFAULTFACTORTABLE to set a default of Activity Factor table for all the services. Use SET USERGBR to set GBR for BE services

CAC Based on Number of HSPA Users

« HSPA user number can be limited in:

• Cell level

n maximum number of HSPA users in a cell

• NodeB level

n Maximum number of HSPA users in all the cells configured in one

NodeB

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page77 ififr HUAWa

When the HSDPA_UU_ADCTRL is on, the HSDPA services have to undergo HSDPA user number admission decision. When a new HSDPA service attempts to access the network, it is admitted if the number of HSDPA users in the cell and that in the NodeB do not exceed the associated thresholds

When the HSUPA_UU_ADCTRL is on, the HSUPA services have to undergo HSUPA user number admission decision. When a new HSUPA service attempts to access the network, it is admitted if the number of HSUPA users in the cell and that in the NodeB do not exceed the associated thresholds

Key parameters • HSDPA_UU_ADCTRL

a Parameter ID: HSDPA_UU_ADCTRL

® Maximum HSDPA user number

• Parameter ID: MaxHSDSCHUserNum

a The default value of this parameter is 64

* HSUPA_UU_ADCTRL

a Parameter ID: HSUPA_UU_ADCTRL

« Maximum HSUPA user number

a Parameter ID: MaxHsupaUserNum


n Similar parameters for Maximum HSPA user number in NodeB level can be set by ADD NODEBALGOPARA

Copyright ©2009 Huawei Technologies Co., Ltd. Ail rights reserved. Page78 4Pw HUAWGI

Maximum HSDPA user number Parameter ID: MaxHSDSCHUserNum Value range: 0 to 100 Content: This parameter specifies the maximum number of HSDPA users in a cell. The default value of this parameter is 64 Set this parameter through ADD CELLCAC/MOD CELLCAC

HSDPA_UU_ADCTRL Parameter ID: HSDPA_UU_ADCTRL Value range: 0 ,1 Content: This parameter specifies whether to enable or disable the HSDPA admission control algorithm. Set this parameter through ADD CELLALGOSWfTCH_/_LST CELLALGOSWITCH/MOD CELLALGOSWITCH

HSUPA_UU_ADCTRL Parameter ID: HSUPA_UU_ADCTRL Value range: 0 ,1 Content: This parameter specifies whether to enable or disable the HSDPA admission control algorithm. Set this parameter through ADD CELLALGOSWITCH /MOD CELLALGOSWITCH

Maximum HSUPA user number Parameter ID: MaxHsupaUserNum Value range: 0 to 100 Content: This parameter specifies the maximum number of HSDPA users in a cell. The default value of this parameter is 20 Content: This parameter specifies the maximum number of HSUPA users in a celL Set this parameter through ADD CELLCAC / MOD CELLCAC

W Contents 2. Load Control Algorithms



23 CAC (Call Admission Control)




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Why we need IAC? * The disadvantage of CAC

n For PS NRT (Non-Real Time) services, CAC is not flexible

• No consideration about the priority of different users

• No consideration about Directed Retry after CAC rejection

• "Intelligent" means the algorithm can increase admission

successful rate

Copyright © 2009 Huawei Technologies Co., Ltd- All rights reserved. PageSO wW HUAWGi

CAC limits the setup of RRC and RAB . When the cell is overloaded , the CAC will cause access failure.

In order to improve the access success rate, the Intelligent Access Control (IAC) algorithm is used to improve the access success rate. The IAC procedure includes rate negotiation, Call Admission Control (CAC), preemption, queuing, and Directed Retry Decision (DRD).

V

AC Overview ie access procedure (include the IAC)

RRC connection request

B setup request

DRD a lgo r i t hm

Service steering DRD

sad balancing DRD

R R C c o n n e c t i o n p r o c e s s i n g

Failed Admission algorithm DRD Failed Redirection

Succeeded Succeeded

Yes

R A B p r o c e s s i n g

„—-~~!s t h e r e a n y ~ - ~ ^ ~-~^ce!l no t tr ied2<

Mo

Failed

Rate negot ia t ion PS domain:

maximum rate

PS and CS domains: initial rale

PS domain; GBR of PS RT service Target Rate Negotiation

Failed Preemption

A d m i s s i o n a lgo r i thm

Load admission

Code admission

lob resource admission

Queuing U Failed or

not supported

Credit admission {Succeeded Service request

accepted J

HSPA user if; number admission!}:

Service request | denied

Qht )<c a*-*/ JlJfJ jy' HAM

As shown in the Figure, the procedure for the UE access includes the procedures for RRC connection setup and RAB setup. The success in the RRC connection setup is one of the prerequisites for the RAB setup. During the RRC connection processing, if resource admission fails, DRD and redirection apply. During the RAB processing, the RNC performs the following steps: • Performs RAB DRD to select a suitable cell to access, for service steering or load balancing. • Performs rate negotiation according to the service requested by the UE. • Performs cell resource admission decision. If the admission is passed, UE access is granted. Otherwise, the RNC performs the next step. • Selects a suitable cell, according to the RAB DRD algorithm, from the cells where no admission attempt has been made, and then goes to rate negotiation and cell resource admission again. If all DRD admission attempts to the cells fail, go to the next step. • Makes a preemption attempt. If the preemption is successful, UE access is granted. If the preemption fails or is not supported, the RNC performs the next step, queuing. • Makes a queuing attempt. If the queuing is successful, UE access is granted. If the queuing fails or is not supported, the RNC Rejects UE access.

81

AC - RRC Connection Processing 1. RRC CONNECTION REQUEST

Yes i

Decide t • direction

2. RRC CONNECTION REJECT

2. RRC CONNECTION SETUP

3. RRC CONNECTION SETUP COMPLETE

KZJ When a new service accesses the network, an RRC connection must be set up first. If the RRC

connection request is denied, DRD is performed. If DRD also fails, RRC redirection is performed to direct the UE to an inter-frequency or inter-RAT cell through cell reselection.

After the RNC receives the RRC CONNECTION REQUEST message, the CAC algorithm decides whether an RRC connection can be set up between the UE and the current cell.

If the RRC connection can be set up between the UE and the current cell, the RNC sends an RRC CONNECTION SETUP message to the UE. If the RRC connection cannot be set up between the UE and the current cell, the RNC takes the following actions:

RRC DRD : If the DRD_SWITCH is set to 0, the RRC DRD fails, and RRC redirection is performed. Else, the RNC performs the following steps:

1. The RNC selects inter-frequency neighboring cells of the current cell. These neighboring cells are suitable for blind handovers.

2. The RNC generates a list of candidate DRD-supportive inter-frequency cells. The quality of the candidate cell meets the requirements of inter-frequency DRD:

( C P I C H J E c / N o ) ^ > DRD_Ec/No nbce(|

where (CPICH_Ec/No)RACH is the cached CPICH Ec/NO value included in the RACH RRC

CONNECTION REQUEST measurement report. DRD_Ec/No nbcel| is the DRD Ec/NO Threshold set for the inter-frequency neighboring cell.

RNC selects a target cell from the candidate cells for UE access. If the candidate cell list contains more than one cell, the UE tries a cell randomly.

1. If the admission is successful, the RNC initiates an RRC DRD procedure. 2. If the admission to a cell fails, the UE tries admission to another cell in the candidate cell

list. If all the admission attempts fail, the RNC makes an RRC redirection decision. If the candidate cell list does not contain any cell, the RRC DRD fails. The RNC performs the next step, that is, RRC redirection.

RRC redirection, the RNC performs the following steps: 1. The RNC selects all inter-frequency cells of the local cell. 2. The RNC selects candidate cells. That is, exclude the cells to which inter-frequency RRC

DRD attempts have been made from the cells selected in the previous step. 3. If more than one candidate cell is available, the RNC selects a cell randomly and redirects

the UE to the cell.

Key parameters * DRD Ec/NO threshold

D Parameter ID: DRDEcNOThreshhold

• The default value of this parameter is -18 (-9 dB)

• RRC redirect switch

D Parameter ID: RrcRedictSwitch

D The default value of this parameter is Only_To_lnter_Frequency

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved

DRD Ec/NO Threshold Parameter ID: DRDEcNOThreshhold Value range: -24 to 0 ,step :0.5dB Content: This parameter is used as the DRD Ec/No threshold of whether to perform the blind handover. If the Ec/No measured value of the current cell is greater than this parameter of the inter-frequency neighboring cell, this neighboring cell can be selected to be the candidate DRD cell. The default value of this parameter is -18 (-9 dB) Set this parameter through ADD INTERFREQNCELL

RRC Redirect switch Parameter ID: RrcRedictSwitch Value range: OFF, Only_To_lnter_Frequency, Allowed_To_lnter_RAT Content: This parameter specifies the RRC redirection strategy. The default value of this parameter is Only_Tb_lnter_Frequency Set this parameter through SET DRD

Page84 i f e HUAW6J

IAC - PS Rate Negotiation • PS Service Rate Negotiation Includes:

• Maximum expected rate negotiation

D Initial rate negotiation

• Target rate negotiation

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. PageSS I U HUAW6I

2 negotiation includes the maximum expected rate negotiation, initial rate negotiation, and target rate negotiation. hen setting up, modifying, or admitting a PS service (conversational, streaming, interactive, or background service) the RNC and the CN negotiate the rate according to the UE capability to obtain the maximum expected rate while snsuring a proper QoS.

>r a non-real-time service in the PS domain, the RNC selects an initial rate to allocate bandwidth for the service when Setup or UE state transits from CELL_FACH to CELL_DCH based on cell code and credit resource Initial rate selection is affected by 2 algorithm switches: RAB Downsizing Switch, DCCC Switch .

"or DCH For HSUPA

Dow asking Svriteb^

*

F->

DCCC Switch*"

ONV

ON*

OFF--

Actual Initial Access Rate for DCH'

MmfX'L/DL BE traffic Inifbl bit rate, the negotiated rate based on cell resources) *•'

I T D L BE traffic Initial bit rate."

Maximum expected rate.' ce

\ RAB Downsizing Suite »•'

o»

iOFF.'

F

HSUPA DCCC Switch-

ON-

ON-"

OFF<= 1

.VtaaHnitJal Access Rate for HSUPA*>

Mimlnitial rate 0/ HSUPA BE traffic, the negotiated rate based on cell resources)."

Initial rate of HSUPA BE t ra f f i c

• Maximum, expected rate~

Key parameters • RAB_Downsizing_Switch

a Parameter ID: RAB_DOWNSIZING_SWITCH

D The default value of this parameter is 1 (on)

• UL/DL BE traffic Initial bit rate

a Parameter ID:

a ULBETRAFFINITBITRATE/ DLBETRAFFINITBITRATE

a The default value of this parameter is D64 (64k)

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page86 miHm H U A W G 1

RAB_Downsizing_Switch Parameter ID: RAB_DOWNSIZING_SWITCH Value range: (0,1) Content: This parameter specifies whether to support the FJAB downsizing function. The default value of this parameter is 1 (on) When this parameter is set to 1, the FJAB downsizing function is applied to determine the initial bit rate based on cell resources (code and credit).. Set this parameter through SET CORRMALGOSWITCH

UL/DL BE traffic Initial bit rate Parameter ID: ULBETRAFFINITBITRATE / DLBETRAFFINITBITRATE Value range: D8, D16, D32, D64, D128, D144, D256, D384, D768, D1024, D1536, D1800, D2048k Content: This parameter defines the uplink initial access rate of background and interactive services in the PS domain. The default value of this parameter is D64 (64k) Set this parameter through SET FRC

IAC - RAB Directed Retry Decision • RAB Directed Retry Decision (DRD) is used to select a suitable

cell for the UE to try an access

D Inter-frequency DRD

• Service Steering

• Load Balancing

• Inter-RATDRD

Copyright © 2009 Huawei Technologies Co., Ltd. Ail rights reserved. Page87 #1 HUAWSI

Through the RAB DRD procedure, the RNC selects a suitable cell for RAB processing during access control. RAB DRD is of two types: inter-frequency DRD and inter-RAT DRD. For inter-frequency DRD, the service steering and load balancing algorithms are available.

After receiving a RANAP RAB ASSIGNMENT REQUEST, the RNC initiates an RAB DRD procedure to select a suitable cell for RAB processing during access control.

The RNC performs inter-frequency DRD firstly. If all admission attempts of inter-frequency DRD fail, the RNC performs an inter-RAT DRD. If all admission attempts of inter-RAT DRD fail, the RNC selects a suitable cell to perform preemption and queuing .

Relation Between Service Steering DRD and Load Balancing DRD When both service steering DRD and load balancing DRD are enabled, the general

principles of inter-frequency DRD are as follows: « Service steering DRD takes precedence over load balancing DRD. That is,

preferably take service priorities into consideration. • To services of the same service priority, load balancing applies.

-- ••»

IAC - RAB Directed Retry Decision RAB Directed Retry Switchs

i^ 1

Scenario

DRD switch

Combined services

HSDPA service

HSUPA service

RAB modification

DCCC

RAB setup

Switch

DRD_SWITCH

COMB_SERV_DRD_SWITCH

HSDPA_DRD_SWITCH

HSUPA_DRD_SWITCH

RAB_MODIFY_DRD_SWITCH

RAB_DCCC_DRD_SWITCH

RAB_SETUP_DRD_SWITCH

Description

This is the primary DRD algorithm switch. The secondary DRD switches are valid only wher. this switch is on.

DRD is applicable to combined services only when this switch is on.

DRD is applicable to HSDPA services only when this switch is on.

DRD is applicable to HSUPA services only when this switch is on.

DRD is applicable to RAB modification only when this switch is on.

DRD is applicable to traffic-volume-based DCCC procedure or UE state transition, only when this switch is on.

DRD is applicable to RAB setup only when this switch is on.

DRD algorithm switch Parameter ID: DRDSWITCH The default value of this parameter is off Set this parameter through SET CORRMALGOSWITCH

IAC » Inter

I

- Inter-frequency DRD -Frequency DRD for Service Steering

T7 • .

DRD for Service Steering is based on Service priorities of cells .include:

- R99 RT services priority

- R99 NRT services priority

- HSPA services priority

- Other services priority

Called Service priority group

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If the UE requests a service in an area covered by multiple frequencies, the RNC selects the cell with the highest service priority for UE access, based on the service type of RAB and the definitions of service priorities in the cells.

Cell service priorities help achieve traffic absorption in a hierarchical way. The priorities of specific service types in cells are configurable. If a cell does not support a

service type, the priority of this service type is set to 0 in this cell. The service priorities in each cell is called Service priority group , which is identified by

the Service priority group Identity parameter. Service priority groups are configured on the LMT. In each group, priorities of R99 RT

services, R99 NRT services, HSPA services, and other services are defined. When selecting a target cell for RAB processing, the RNC check the service type firstly ,

then, selects a cell with a high priority for the service, that is, a cell that has a small value of service priority.

IAC - Inter-frequency DRD • Inter-Frequency DRD for Service Steering

Service priority group

Identity

1

2

Service priority of R99 RT

service

2

1

Service priority o f R M N R T

service

1

2

Service priority of HSPA service

1

0

Service priority of

other service

0

0

Cell A B

Service priori ty group Identity

1 2 tftt* m h-M/J

V::>; C8SA

RTBorvic*


Cell A and cell B are of different frequencies. Assume that the service priority groups given in the table are defined on an RNC, 2

groups of service priorities are defined. Then ,Cell A is configured with service priority group 1. Cell B is configured with service

priority group 2 If UE requests a R99 RT service in cell A .Cell B has a higher service priority of the R99

RT service than cell A. If the UE requests an RT service in cell A, preferably, the RNC selects cell B for the UE to access.

IAC - Inter-frequency DRD » Inter-Frequency DRD procedure for Service Steering

Receive a service request

Determine candidate cells

HSPA falls back to DCH

Determine a target cell in order of priority"*"

[thA i

reques ISPA

candidate jccessfu

nitrate a blind handover

initiate an inter-RAT DRD

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The procedure for the service steering DRD is as follows: 1 . The RNC determines candidate cells to which blind handovers can be performed and sorts the

candidate cells into a descending order according to service priority. A candidate cell must meet the following conditions:

• The frequency of the candidate cell is within the band supported by the UE. • The quality of the candidate cell meets the Ec/No requirements of inter-frequency DRD (DRD

Ec/NO Threshold ) • The candidate cell supports the requested service.

2> The RNC selects a target cell from the candidate cells in order of service priority for UE access. 3. The CAC algorithm makes an admission decision based on the status of the target cell.

• If the admission attempt is successful, the RNC accepts the service request. • If the admission attempt fails, the RNC removes the cell from the candidate cells and then

choose next candidate cell. 4, If admission decisions have been made in all the candidate cells

• For HSPA access, the HSPA request falls back to a DCH one. Then, the algorithm goes back to Step 1 to make an admission decision based on R99 service priorities.

• For DCH access, the RNC initiates an inter-RAT DRD.

Key parameters » DRD Ec/NO Threshold

a Parameter ID: DRDEcNOThreshhold

o The default value of this parameter is -18 (-9dB)

• Service differential drd switch

• Parameter ID: ServiceDiffDrdSwitch

o The default value of this parameter is OFF

• Service priority group Identity

a Parameter ID: PriorityServiceForR99RT

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page92 W W H U A W E I

DRD Ec/NO Threshold Parameter ID: DRDEcNOThreshhold Value range: -24-0 .Step: 0.5dB Content: This parameter is used as the DRD Ec/No threshold of whether to perform the blind handover. If the Ec/No measured value of the current cell is greater than this parameter of the inter-frequency neighboring cell, this neighboring cell can be selected to be the candidate DRD cell. The default value of this parameter is -18. Set this parameter through ADD INTERFREQNCELL

Service differential drd switch Parameter ID: ServiceDiffDrdSwitch Value range: ON, OFF Content: This parameter specifies whether to enable the service steering DRD algorithm The default value of this parameter is OFF. Set this parameter through ADD CELLDRD/SET DRD

Service priority ofR99 RT service Parameter ID: Spgld Value range: 1 to 8 Content: This parameter uniquely identifies a group of service priorities that map to cells and indicate the support of each cell for the following service types: R99 RT service, R99 NRT service, HSPA service, and other services.

Set this parameter through ADD SPG

When define a cell by ADD CELLSETUP, this SPG ID is a mandatory parameter

Key parameters • Service priority of R99 RT service

o Parameter ID: Spgld

• Service priority of R99 NRT service

• PriorityServiceForR99NRT

• Service priority of HSPA service

a PriorityServiceForHSPA

« Service priority of Other service

a PriorityServiceForExtRab

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Service priority of R99 RT service Parameter ID: PriorityServiceForR99RT Value range: 0 to 7 Content: This parameter specifies the support of the cells with a specific Service priority group Identity for R99 RT services. The value 0 means that these cells do not support R99 RT services. For the values 1 through 7, the service priority is inversely proportional to the value, that is, the value 7 indicates the lowest service priority, whereas the value 1 indicates the highest. Set this parameter through ADD SPG

Service priority of R99 NRT service Parameter ID: PriorityServiceForR99NRT Value range: 0 to 7 Content: This parameter specifies the support of the cells with a specific Service priority group Identity for R99 NRT services. The value 0 means that these cells do not support R99 NRT services. For the values 1 through 7, the service priority is inversely proportional to the value, that is, the value 7 indicates the lowest service priority, whereas the value 1 indicates the highest. Set this parameter through ADD SPG

Service priority of HSPA service Parameter ID: PriorityServiceForHSPA Value range: 0 to 7 Content: This parameter specifies the support of the cells with a specific Service priority group Identity for HSPA services. The value 0 means that these cells do not support HSPA services. For the values 1 through 7, the service priority is inversely proportional to the value, that is, the value 7 indicates the lowest service priority, whereas the value 1 indicates the highest. Set this parameter through ADD SPG

Service prionty of Other service Parameter ID: PriorityServiceForExtRab Value range: 0 to 7 Content: This parameter specifies the support of the cells with a specific Service priority group Identity for Other services . The value 0 means that these cells do not support Other service . For the values 1 through 7, the service priority is inversely proportional to the value, that is, the value 7 indicates the lowest service priority, whereas the value 1 indicates the highest. Set this parameter through ADD SPG

IAC - Inter-frequency DRD • Inter-Frequency DRD for Load Balance

• The resources triggering DRD for Load Balance include:

• DL Power

. OVSF code

D Any of these 2 resources can trigger inter-frequency DRD for Load Balance

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page9S 4$ HUAWEI

Load balancing considers two resources: power, and code. In practice, it is recommended that only either a power-based load balancing DRD or a code-based load balancing DRD is activated. If both are activated, power-based load balancing DRD takes precedence over code-based load balancing DRD. Code-based load balancing DRD is applicable to only R99 services because HSDPA services use reserved codes.

IAC - Inter-frequency DRD • Power load balancing DRD

a Two algorithms can be used to judge the load of the cells:

• Algorithm 1: The load balancing DRD is performed according to the cell measurement values about the DL non-HSDPA power and DL HS-DSCH required power.

• Algorithm 2: The bad balancing DRD is performed according to the DCH Equivalent Number of Users (ENU) and HSDPA user number.

• Load balance DRD choice

• Parameter ID: LdbDRDchoice

D The default value of this parameter is UserNumber

• : I .


Two algorithms are available for power load balancing. If the power load balancing DRD is enabled, one of them can be used, and the algorithm used is defined by the Load balance DRD choice parameter. Algorithm 1: The load balancing DRD is performed according to the cell measurement values about the DL non-HSDPA power and DL HS-DSCH required power. For DCH service, the RNC sets up the service on a carrier with a light load of non-HSDPA power to achieve load balancing among the cells on the different frequencies. For HSDPA service, the RNC sets up the service on a carrier with a light load of HS-DSCH required power to achieve load balancing among the cells on different frequencies. Algorithm 2: The load balancing DRD is performed according to the DCH Equivalent Number of Users (ENU) and HSDPA user number. For DCH service, the RNC sets up the service on a carrier with a light load of DCH ENU to achieve load balancing among the cells on different frequencies. For HSDPA service, the RNC sets up the service on a carrier with a light toad of HSDPA user to achieve load balancing among the cells on different frequencies.

Load balance DRD choice Parameter ID: LdbDRDchoice Value range: Power~1, UserNumber~0 Content: This parameter specifies which choice the load balancing DRD algorithm will be applied. - Power: Power Downlink none-HSDPA power is used for services carried on DCH, and downlink HSDPA guarantee power is used for services carried on HS-DSCH) will be applied to the load balancing DRD algorithm. - UserNumber: User number (Downlink R99 equivalent user number is used for services carried on DCH, and downlink HSDPA user number is used for services carried on HS-DSCH) will be applied to the load balancing DRD algorithm. The default value of this parameter is UserNumber. Set this parameter through SET DRD

Inter-frequency DRD >ower load balancing DRD

HSPA falls back to DCH

Receive a service request

s power of the cunr ell meet DRD conditions

(condition 1 )*

oes power of a neighboring cell meet DRD conditions

edition 2)?

Are there multiple such cells available?

Yes

Select the cell meeting the DRD conditions as

the target ceil

Select the cell with the lightest power load as

the target ceil

Select the current cell as the target cell

Are all andidaie cells

tried?

CAC successful?

Is the request - ^ an HSPA one?

nitiaie a blind handover

initiate an inter-RAT DRD

2. If

The procedure for power-based load balancing DRD is as follows: • The RNC determines the candidate cells to which blind handovers can be performed. A candidate cell must meet the following conditions:

The frequency of the candidate cell is within the band supported by the UE. • The quality of the candidate cell meets the requirements of inter-frequency DRD. • The candidate cell supports the requested service.

If the current cell is not a candidate cell, the RNC selects a cell with the lightest load from the candidate cells as the target cell to do admission for the service. If the current cell is a candidate cell as well, RNC need to consider the current cell load condition (condition-!, described below), if current cell load is not higher than a threshold , means conditionl is met, RNC just do admission for the service in the current cell regardless the neighbors. Otherwise (conditionl is not met) ,RNC need to evaluate the load difference between the current cell and other candidate neighbors, if the load difference between current cell and a neighbor is larger than a threshold (concition2, described below), then this neighbor is an available target cell. After the filtration of the conditionl and condition2, If there are multiple such ceils , RNC select the cell with lightest load as the target cell, (the method to select the cell with lightest load is described below. ). If there is no such cell, the RNC selects the current cell as the target ce l l . The CAC algorithm makes an admission decision on the target cell. If the admission attempt is successful, the RNC admits the service request. If the admission attempt fails, the RNC checks whether admission decisions have been made in all candidate inter-frequency neighboring cells. If there is any cell where no admission decision is made, the algorithm goes back to 2. If admission decisions have been made in all the candidate cells:

• When the service request is an HSPA one, the HSPA request falls back to a DCH one. Then, the algorithm goes back to 1 to make an admission decision based on R99 service priorities. When the service request is a DCH one, the RNC initiates an inter-RAT DRD.

The condition 1 is defined as: $ For the algorithm 1, the condition 1 is as follows: y ^ a. For DCH bearer / - '

\y¥* AMR,cutceIl ~ * non-H,cutcell ) > 4 " " n o n - H

b. For HSDPA bearer o/HM"*^ ^ ^ ^

\1 rl<* ̂ 1 cutcett ~ fGBP,cutcell ) > * "C'H

For the algorithm 2, the condition 1 is as follows: a. For DCH bearer

(™A1 HSDPA be

-P )> Thd MR,cutcell 1 D-ENU,cutcell ) L nU non-H

b. For HSDPA bearer

_ P cutcell H-tie ,cutcell

)lThdH_ttecutcell>ThdH Where

Thd. Thd,,

is Dl load balance DRD power remain threshold for DCH of the current cell, is Dl load balance DRD power remain threshold for HSDPA of the current cell.

The condition 2 is defined as: If the algorithm 1 is used , the condition 2 is as follows: a. For an HSDPA service

{™total,n

(Thdi

bcell *GBP,nbcell ) \ ^ total, - P

cutcell GBP,cutcell

total, cutcell load,cutcell b. For a DCH service

)-(Thd K total ,nbcell load ,nbcell

) > ThdH

) < Th di total Joadi

yl hClAMR>nbceu *non-H ,nbcell ) \* "" AMR, cutcell *non-H .cutcell ) > * ""DJc--

yl TIMtotai cutceu ~ * load,cutcell j V ^total,nbcell ~ "load ,nbcell ) < * "^total Joado If the algorithm 2 is used ,the condition 2 is as follows: a. For an HSDPA service

yi ndH_uenbceU *H-ue,nbcel1 ) ' * ""H-ue,nbcell \f "&H-ite,cutcell ^H-rn,cutcell ) ' * ""H-i •ue.cuh

>Thd H Joadoffset

b. For a DCH service

[Thd - p AMR,nbcell D-enu,nbcell

)-(Thd AMR,cutcell D-enu,cutcell ) > ThdD loadoffsi

Current cell

*™*Malma&

p 1 G2?f!&ce&

P

P

1 rWjt&jaixdt

^•^H-ucci&eE

p

p

*™dB&ad&a

*""• n.ba&&iet

* ""fitt!J^xa&>j£tf

Inter-fr e quenc y neighbor ing cell

tîeialjitem

p 1 SSPjttvdl

P hadtHbce8

p HM-JixicsS

1 ^ " J M B , S » **

2 ^«jyHBf,M»1a?S

Pif-mxiedl

p

-

-

-

-•••••-- •-•••— ———••--••——-— Description


HS-DSCH re quired power load (GBP)

Total power load. It is the sum of the non-HSDPA power and GBP.

Non-HSDPA power load

DL threshold of Conv AMR service

Maximum HSDPA user number

Number of all existing HSDPA users

Total ENU of all existing DCH services

Load balance DRD offset for HSDPA

Load balance DRD offset for DCH

Load balance DRD total power protect threshold

The method for RNC to select cell with lightest load Is : • For DCH service If the algorithm 1 is used, the RNC selects the cell with the lightest non-HSDPA load as the target cell. If the algorithm 2 is used, the RNC selects the cell with the lightest load of DCH ENU as the target cell. • For HSDPA service If the algorithm 1 is used, the RNC selects the cell with the lightest load of HS-DSCH required power

as the target cell. If the algorithm 2 is used, the RNC selects the cell with the lightest load of HSDPA user as the target

cell.

Key parameters • Load balance DRD switch for DCH

o Parameter ID: LdbDrdSwitchDCH

n The default value of this parameter is OFF

• Load balance DRD switch for HSDPA n Parameter ID: LdbDrdSwitchHSDPA

• The default value of this parameter is OFF

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved- PagelOO iPflHUAWei

Power balance DRD switch on DCH Parameter ID: LdbDrdSwitchDCH Value range: ON, OFF Content: This parameter specifies whether to enable the power-based load balancing DRD algorithm for DCH service . The default value of this parameter is OFF. Set this parameter through SET DRD / ADD CELLDRD

Power balance DRD switch on HSDPA Parameter ID: LdbDrdSwitchHSDPA Value range: ON, OFF Content: This parameter specifies whether to enable the power-based load balancing DRD algorithm for HSDAP service . The default value of this parameter is OFF. Set this parameter through SET DRD /ADD CELLDRD

Key parameters • Dl toad balance DRD power remain threshold for DCH

a Parameter ID: LdbDRDLoadRemainThdDCH


• Dl load balance DRD power remain threshold for HSDPA

a Parameter ID: LdbDRDLoadRemainThdHSDPA


Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. PagelOl igfm HUAWEI

Dl load balance DRD power remain threshold for DCH Parameter ID: LdbDRDLoadRemainThdDCH Value range: 0-100% Content: This parameter specifies the downlink load threshold to trigger load balancing DRD for services carried on DCH. The load balancing DRD will probably be triggered only when the downlink cell remanent non H power or remanent R99 equivalent user number is less than this threshold . The default value of this parameter is 35% Set this parameter through SET DRD

Dl load balance DRD power remain threshold for HSDPA Parameter ID: LdbDRDLoadRemainThdHSDPA Value range: 0-100% Content: This parameter specifies the downlink load threshold to trigger load balancing DRD for services carried on HS-DSCH. The load balancing DRD will probably be triggered only when the downlink cell remanent HSDPA guarantee power or remanent HSDPA user number is less than this threshold. The default value of this parameter is 100%. Set this parameter through SET DRD

Key parameters « DL total power threshold

a Parameter ID: DLCELLTOTALTHD

a The default value of this parameter 90%

* Load balance DRD offset for DCH a Parameter ID: LdbDRDOffsetDCH


• Load balance DRD offset for HSDPA • Parameter ID: LdbDRDOffsetHSDPA


• Load balance DRD total power protect threshold • Parameter ID: LdbDRDTotalPwrProThd


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DL total power threshold Parameter ID: DLCELLTOTALTHD Value range: 0-100% Content: Admission threshold of the total cell downlink power. If the value is too high, too many users will be admitted. However, the throughput of a single user is easy to be limited. If the value is too low, cell capacity will be wasted. The default value of this parameter is 90% Set this parameter through SET DRD

Load balance DRD offset for DCH Parameter ID: LdbDRDOffsetDCH Value range: 0-100% Content: This parameter specifies the threshold of remanent load offset between the current cell and the target cell when load balancing DRD is applied for DCH users. Only when the remanent load offset reaches this threshold can a neighboring cell be selected as a candidate DRD cell for DCH users. The default value of this parameter is 10%. Set this parameter through SET DRD

Load balance DRD offset for HSDPA Parameter ID: LdbDRDOffsetHSDPA Value range: 0-100% Content: This parameter specifies the threshold of remanent load offset between the current cell and the target cell when load balancing DRD is applied for HSDPA users. Only when the remanent load offset reaches this threshold can a neighboring cell be selected as a candidate DRD cell for HSDPA users. The default value of this parameter is 10% Set this parameter through SET DRD

Load balance DRD total power protect threshold Parameter ID: LdbDRDTotalPwrProThd Value range: 0% to 100% Content: This parameter specifies the threshold of the downlink remanent total power difference between the current cell and the target cell when load balancing DRD is applied and the load balancing DRD choice is Power. Only when the downlink remanent total power difference is less than this threshold can a neighboring cell be selected as a candidate DRD cell. Set this parameter through SET DRD

Z - Inter-frequency DRD Inter-Frequency DRD procedure for Code Load Balance

current cell involve' t he decis ion?

irrimum SF of the current oe M i n i m u m S F t h r e s h o l d f o r

o d e b a l a n c i n g d r d 2

ode load of the current cell < >de o c c u p i e d r a t e t h r e s h o l d f«

o d e b a l a n c i n g drd2-

N o

Y e s

N o

o r t cd m m urn

Y e s

Select the cell wi th the l ightest code toad as the target cell

Yes

N o

< r Select the

current ceil as the target cell

Select the cell with the l ightest code load f rom the cei ls wi th the same service priority

as the target cell

The procedure is as follows: 1. The RNC determines whether the minimum remaining spreading factor of the current cell is

smaller than Minimum SF threshold for code balance DRD. • If the minimum SF is smaller than Minimum SF threshold for code balance DRD, the RNC

tries the admission of the service request to the current cell. • If the minimum SF is not smaller than Minimum SF threshold for code balance DRD, the RNC

performs the next step. 2. The RNC determines whether the code load of the current cell is lower than Code occupied

rate threshold for code balance DRD. « If the code load is lower than Code occupied rate threshold for code balance DRD, the

service tries the admission to the current cell. • If the code load is higher than or equal to Code occupied rate threshold for code balance

DRD, the RNC selects the cell with the lightest load or the current cell as the target cell. The RNC selects the cell as follows:

• If the minimum SF supported by the cell with the lightest code load is the same as the minimum SF supported by the current cell, and the difference between the code resource occupancies of the cell and the current cell is larger than or equal to the value of Delta code occupied rate, the RNC selects the cell with the lightest code load as the target cell. Otherwise, the RNC selects the current cell as the target cell.

• If the minimum SF supported by the cell with the lightest code load is smaller than the minimum SF supported by the current cell, the RNC selects the cell with the lightest code load as the target cell.

103

Key parameters • Code balancing drd switch

n Parameter ID: CodeBalancingDrdSwitch

• The default value of this parameter is OFF

• Minimum SF threshold for code balancing drd

a Parameter ID: CodeBalancingDrdMinSFThd

n The default value of this parameter is SF8

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Pagel 04 4$$£ HUAWEI

Code balancing drd switch Parameter ID: CodeBalancingDrdSwitch Value range: ON, OFF Content: This parameter specifies whether to enable the code-based load balancing DRD algorithm. The default value of this parameter is OFF. Set this parameter through SET DRD / ADD CELLDRD

Minimum SF threshold for code balancing drd Parameter ID: CodeBalancingDrdMinSFThd Value range: SF4, SF8, SF16, SF32, SF64, SF128, SF256 Content: If the downlink minimum SF of the best cell is below this threshold, the code-based load balancing DRD is not triggered. The default value of this parameter is SF8 . Set this parameter through SET DRD / ADD CELLDRD

Key parameters • Code occupied rate threshold for code balancing drd

a Parameter ID: CodeBalancingDrdCodeRateThd


• Delta code occupied rate

n Parameter ID: DeltaCodeOccupiedRate


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Code occupied rate threshold for code balancing drd Parameter ID: CodeBalancingDrdCodeRateThd Value range: 0% to 100% Content: This parameter specifies the code occupancy threshold of the current cell for code-based load balancing DRD.Only when the code occupancy of the best cell reaches this threshold can code-based load balancing DRD be triggered. The default value of this parameter is 13%. Set this parameter through SET DRD / ADD CELLDRD

Delta code occupied rate Parameter ID: DeltaCodeOccupiedRate Value range: 0% to 100% Content: This parameter specifies the code occupied rate offset threshold of the current cell and the inter-frequency cell when code balancing drd algorithm is applied. Only when the code occupied rate offset reaches this threshold, the inter-frequency cell can be selected to be the target drd cell. The default value of this parameter is 7% . Set this parameter through SET DRD

[AC - Inter-RAT DRD Inter-RAT DRD

Receive an Inter-RAT DRD request

Criteria for inter RAT blind handovei

fulfilled?

Can a list of andidate cells b

generated?

Try admission to the target cell in order of

blind handover priority

Adm Max

Preemption or queuing

itiate an inter-RAT handover

The inter-RAT DRD procedure is as follows: 1,If the current cell is configured with any neighboring GSM cell suitable for blind

handover and the Service Handover Indicator is set to HO_TO_GSM_SHOULD_BE_PERFORM, the RNC performs next step. Otherwise, the service request undergoes preemption and queuing.

2,The RNC generates a list of candidate DRD-supportive inter-RAT cells that fulfill the following requirement:

(CPICH_EcNo) > DRD_EcN®>, nbceU

where - (CPICH_EcNo)RACH

is t h e cached CPICH Ec/NO value included in the RACH measurement report. - (DRD_EcNo)nbcell is the DRD Ec/NO Threshold set for the inter-RAT neighboring cell.

3,The service request then tries admission to a target GSM cell in order of blind handover priority.

4,lf all admission attempts fail or the number of inter-RAT directed retries exceeds 2, the service request undergoes preemption and queuing.

Inter-RAT DRD is only available for AMR service in RAN 10:

Key parameters • DRD Ec/NO Threshold

n Parameter ID: DRDEcNOThreshhold

n The default value of this parameter is -18 (-18dB)

* Max inter-RAT direct retry number

p Parameter ID: DRMaxGSMNum

• The default value of this parameter is 2

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DRD Ec/NO Threshold Parameter ID: DRDEcNOThreshhold Value range: -24-0 , Content: This parameter is used as the DRD Ec/No threshold of whether to perform the blind handover. If the Ec/No measured value of the current cell is greater than this parameter of the inter-RAT neighboring cell, this neighboring cell can be selected to be the candidate DRD cell. The default value of this parameter is -18. Set this parameter through ADD GSMNCELL

Max inter-RAT direct retry number Parameter ID: DRMaxGSMNum Value range: 0 to 5 Content: This parameter defines the maximum number of inter-RAT directed retries for an RAB. The value 0 means that inter-RAT DRD is not allowed. The default value of this parameter is 2 Set this parameter through ADD CELLDRD

IAC - Preemption and Queuing

> After cell admission fails, the RNC performs preemption and

Queuing

n Precondition of Preemption and Queuing - According to CN setting, Preemption and Queuing is supported

E "* allocatconOrRetentionPriority

priority'Leve!:Oxc (12) pre-emptonCapabilit^shall-noMrigger-pre-emption (0) pre-emptionVu!nerabil!ty:not-pre-emptab!e (0) queuingAllowed:queueing-allowed(1)

a Target cell of Preemption and Queuing - Based on DRD


Preemption and Queuing guarantees the success in the access of a higher-priority user by forcibly releasing the resources of a lower-priority user.

After cell resource admission fails, the RNC performs Preemption and Queuing if the following conditions are met:

The RNC receives an RAB ASSIGNMENT REQUEST message indicating that Preemption and Queuing is supported.

By default, Preemption and Queuing setting in CN may be:

USER LEVEL

High

Preemption capability

Able

Medium ; Able

Low I Not able „ _ _ . , „ , ™JL_ , _ . _ _ _ _ .

Preemptable

Not allowed

allowed

allowed

Queuing

allowed

allowed

Not allowed

Preemption and Queuing is applicable to the following cases: • Setup or modification of a service Q Hard handover or SRNS relocation • UE state transits from CELL_FACH to CELL_DCH

The RNC selects a suitable cell according to the settings of the DRD algorithms.

<yi 0

Preemption 'motion on different resources

1 Service

|

R99 service

HSDPA

1 HSUPA

Resource

Code

Power

CE

Iub bandwidth

Code

Power

CE

Iub bandwidth

Code

Power

CE

Iub bandwidth

Service That cat

R99 Service

•J

V

7

V

-

V

-

V

-

V

V

V

Be Preempted

HSUPA Service

-

V

V

V

-

-

-

-

-

V

V

V

HSDPA Service

-

V

-

V

-

V

-

V

-

-

-

-

R99 + HSPA Combined Service

V

V

V

V

-

V

-

~J

-

-

V

V

The preemption procedure is as follows: 1 > The preemption algorithm determines which radio link sets can be preempted. The

algorithm proceeds as follows: n Chooses SRNC users first. If no user under the SRNC is available, the

algorithm chooses users under the DRNC. • Sorts the pre-emptable users by user integrate priority, or sorts the pre-

emptable RABs by RAB integrate priority. • Determines candidate users or RABs.

a Only the users or RABs with priorities lower than the RAB to be established are selected.

a Selects as many users or RABs as necessary in order to match the resource needed by the RAB to be established. When the priorities of two users or RABs are the same, the algorithm chooses the user or RAB that can release the most resources.

2^ The RNC releases the resources occupied by the candidate users or RABs. 3> The requested service directly uses the released resources to access the network

without admission decision.

Key parameters • Preempt algorithm switch

a Parameter ID: PREEMPTALGOSWITCH

a The default value of this parameter is OFF

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Pagel10 <||i| HUAWEI

Preempt algorithm switch Parameter ID: PreemptAlgoSwitch Value range: ON, OFF Content: This parameter specifies whether to support the preemption function. The default value of this parameter is OFF Set this parameter through SET QUEUEPREEMPT

IAC-Queuing

• After Preemption rejection, UE can wait in queue, then admission attempts for the service are Tmax expires.

« Admission attempts are

Pqueue = Telapsed

made periodically till

made based on Queuing priority:

• Tmax is the maximum time in the queue,

• Telapsed is the time has

Copyright © 2009 Huawei Technologies Co.,

queued

- H I ( 1 0 1 Ltd. All rights reserved.

default value is 5s

Pagelll ^ # HUAWEI

After the cell resource decision fails, the RNC performs queuing if the RNC receives an RAB ASSIGNMENT REQUEST message indicating the queuing function is supported

The queuing algorithm checks whether the queue is full, that is, whether the number of service requests in the queue exceeds the queue length that is defined by the Queue length

The queuing algorithm is triggered by the heartbeat timer, which is set through the Poll timer length .

If the queue is not full: • Stamps this request with the current time. • Puts this request into the queue.

If the queue is full: • Checks whether there are requests whose integrate priorities are lower than that of the

priority of the new request. If there is, delete the low priority request, put the new service in the queue. (Otherwise, the queuing algorithm rejects the new request directly.)

• Stamps the new request with the current time and then puts it into the queue. After the heartbeat timer (Poll timer length) expires, the queuing algorithm proceeds as follows:

• Selects the request with the highest integrate priority for an attempt of resource allocation . If more than one service has the same highest integrate priority, the RNC calculates the weights of the requests with the same highest integrate priority and chooses the request with the greatest weight for an attempt of resource allocation. The Weight = Telapsed

• If the attempt fails, the queuing algorithm proceeds as follows: • Puts the service request back into the queue with the time stamp unchanged for

the next attempt. • Chooses the request with the greatest weight from the rest and makes another

attempt until a request is accepted or all requests are rejected.

Key parameters * Queue algorithm switch

a Parameter ID: QUEUEALGOSWITCH

a The default value of this parameter is OFF

• Queue length

p Parameter ID: QUEUELEN


• • '.:":•':';:•••':•. •••:.--- ' . •.•• • Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page! 12 l U l HUAW6I

Queue algorithm switch Parameter ID: QUEUEALGOSWITCH Value range: ON, OFF Content: This parameter specifies whether to support the queuing function. The default value of this parameter is OFF Set this parameter through SET QUEUEPREEMPT

Queue length Parameter ID: QUEUELEN Value range: 5 to 20 Content: This parameter defines the length of a queue. The default value of this parameter is 5 Set this parameter through SET QUEUEPREEMPT

A.

Key parameters • Poll timer length

D Parameter ID: POLLTIMERLEN

D The default value of this parameter is 50 (500ms)

• Max queuing time length

a Parameter ID: MAXQUEUETIMELEN

a The default value of this p arameter is 5

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Poll timer length Parameter ID: POLLTIMERLEN Value range: 1 to 6000 , step: 10ms Content: This parameter defines the length of the heartbeat timer. Each time the timer expires, the RNC chooses the service that meets the requirement to make an admission attempt. The default value of this parameter is 50 (500ms) Set this parameter through SET QUEUEPREEIVJPT

Max queuing time length Parameter ID: MAXQUEUETIMELEN Value range: 1 to 60s Content: This parameter defines the maximum time that the service request can be in the queue. The default value of this parameter is 5s Set this parameter through SET QUEUEPREEMPT

IAC for Emergency Calls

• RRC Connection Process

D No admission on power resources

n Admission is successful if the current remaining hard resources are

sufficient

• If the hard resource admission fails preemption is'performed regardless of the preemption switch


Compared with the RRC connection process of ordinary services, the RRC connection process of emergency calls incorporates the preemption due to hard resource admission failure.

In case of power resources, direct admission is used without considering the CAC algorithm switch.

In case of hard resources, (that is, code, Iub, and CE), the resource admission is successful if the current remaining resources are sufficient for the RRC connection.

If the hard resource admission fails, preemption is performed regardless of whether the preemption switch is on or off. The emergency calls that trigger preemption have the highest priority. The range of users that can be preempted is defined by the Preemptvulnerability for emergency call switch parameter.

• If this switch is set to ON, all non-emergency users that have accessed the network can be preempted, regardless of the preemption-prohibited attribute of the users.

• If this switch is set to OFF, only the non-emergency users with preemption-allowed attribute can be preempted.

< x4-

IAC for Emergency Calls

RAB Process

• For power resource admission ,

• if EMC_UU_ADCTRL is on, power admission fails if the system is in overload congestion state. Otherwise, the admission succeeds.

• If the CAC algorithm switch is off, the emergency calls are directly

admitted.

o For hard resources ,the resource admission is successful if the

current remaining resources are sufficient for the request

• If the hard resource admission fails preemption is performed regardless of the preemption switch

Copyright © 2009 Huawei Technologies Co., Ltd. Al l rights reserved. Page115 HUAWEI

In case of power resources: If the CAC algorithm switch is on, regardless of which algorithm is selected, the admission

decision-making is as follows: • When EMC_UU_ADCTRL (set through Cell CAC algorithm switch) is on, power admission

fails if the system is in overload congestion state. Otherwise, the admission succeeds. • When EMC_UU_ADCTRL is off, the emergency calls are directly admitted. If the CAC algorithm switch is off, the emergency calls are directly admitted. For hard resources (that is, code, Iub, and CE), the resource admission is successful if the

current remaining resources are sufficient for the request. If the hard resource admission fails, preemption is performed regardless of whether the

preemption switch is on or off. The emergency calls that trigger preemption have the highest priority. The range of users that can be preempted is defined by the Preemptvulnerability for emergency call switch parameter.

• If this switch is set to ON, all non-emergency users that have accessed the network can be preempted, regardless of the preemption-prohibited attribute of the users.

• If this switch is set to OFF, only the non-emergency users with preemption-allowed attribute can be preempted.

Key parameters • Preemptvulnerability for emergency call switch

• Parameter ID: EmcPreeRefVulnSwitch

• The default value of this parameter is ON (All services)

Copyright S3 2009 Huawei Technologies Co., Ltd. All rights reserved. Pagel 16 : wPW HUAWEI

Preemptvulnerability for emergency call switch Parameter ID: EmcPreeRefVulnSwitch Value range: ON, OFF Content: When the switch is enabled, users of emergency call can preempt all the users of non emergency call. When the switch is disabled, users of emergency call can only preempt users of non emergency call with the preempted attributes. The default value of this parameter is ON Set this parameter through SET QUEUEPREEMPT

a a

&) Contents Load Control Algorithms



2.3 CAC (Call Admission Control)

2.4 IAC (intelligent Admission Control)



Copyright ® 2009 Huawei Technologies Co., Ltd. All rights reserved. Page117 K H U A W E I

LCC (Load Congestion Control) "3 m o

100°/

T H L section B

section C

u Overload state: OLC will be used

Basic congestion state: LDR will be used

Normal state: Permit entry

Junes Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Pagel 18 HUAWEI

LCC (Load Congestion Control) consist of LDR (Load Reshuffling) and OLC (Over Load Control). In basic congestion state, LDR will be used to optimize resource distribution, the main rules is not to affect the feeling of users as possible as we can. In overload state, OLC will be used to release overload state quickly, keep system stability and the service of high priority users.

Load Reshuffling • Reasons

D When the ceil is in basic congestion state, be easily rejected by system

• Purpose

a Optimizing cell resource distribution

new coming calls could

a Decreasing load level, increasing admission successful rate

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page119 0§r- HUAWEI

When the usage of cell resource exceeds the basic congestion triggering threshold, the cell enters the basic congestion state. In this case, LDR is required to reduce the cell load and increase the access success rate.

Load Reshuffling • Triggering of LDR

• Power resources

n Code resource

a Iub resources

D NodeB Credit resource

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page120 4PH HUAWEI

For power resource, the RNC performs periodic measurement and checks whether the cells are congested. For code, Iub, and NodeB credit resources, event-triggered congestion applies, that is, the RNC checks whether the cells are congested when resource usage changes.

Load Reshuffling • LDR Actions:

• Inter-frequency load handover

D Code reshuffling

D BE service rate reduction

n AMR rate reduction

D Inter-RAT load handover in the CS domain

• Inter-RAT load handover in the PS domain

a Real time service Iu QoS renegotiation

D MBMS power reduction

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When the cell is in basic congestion state, the RNC takes one of the actions in each period until the congestion is resolved

~ft\\r>JJA

\ -Jj, ^

j ( y x K i ^ I

f^M ik

Load Reshuffling Actions triggered by different resources

Resourc e

Power

Iub

Code

Credit

UL/ DL

UL

DL

UL

DL

-DL

UL

DL

Channel

DCH

HSUPA

DCH

HSDPA

FACH (MBMS)

DCH

HSUPA

DCH

HSDPA

FACH (MBMS)

-DCH

HSDPA

FACH (MBMS)

DCH

HSUPA

DCH

HSDPA

FACH (MBMS)

LDR Actions

Inter-Freq Load Hand-over

4

4

4

4

4

BE Rate Redu ction

4

4

4

4

4

4

Inter-RAT Handover inCS Domain

4

4

4

4

4

4

Inter-RAT Handover in PS Domain

4

4

4

V

•J

V

V

V

4

V

4

AMR Rate Reduct ion

4

4*

IuQoS Reneg otiatio n

4

4

4

4

4

4

Code Resh ufflin g

4

MRl S Pow Red ic

4*

If the downlink power admission uses the equivalent user number algorithm, basic congestion can also be triggered by the equivalent number of users. In this situation, LDR actions do not involve AMR rate reduction or MBMS power reduction, as indicated by the symbol "*" in above table

Congestion of different resource may trigger different actions. For example, Credit congestion do not trigger "Inter-Frequency Load Handover", "AMR Rate Reduction", and "Code Reshuffling" When congestion of all resources is triggered, the action to be taken is based on the resource priority configuration.

\ \

Key parameters • Cell LDC algorithm switch

a Parameter ID: NBMLDCALGOSWITCH

. UL_UU_LDR M - . p v w

. DL_UU_LDR '"

. CELL_CODE_LDR

• NodeB LDC algorithm switch

a Parameter ID: NodeBLdcAlgoSwitch

. IUBJ.DR

. NODEB_CREDIT_LDR

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page! 23 | P | HUAWEI

Cell LDC algorithm switch Parameter ID: NBMLDCALGOSWITCH Value range: ON, OFF Content: If ULLDR, DLLDR, CELL_CODE_LDR are selected, the corresponding algorithms are enabled.. Set this parameter through ADD CELLALGOSWITCH / MOD CELLALGOSWITCH

NodeB LDC algorithm switch Parameter ID: NodeBLdcAlgoSwitch Value range: ON, OFF Content: If IUB_LDR, NODEB_CREDIT_LDR, are selected, the corresponding algorithms will be enabled; otherwise, disabled.. Set this parameter through ADD NODEBALGOPARA / MOD NODEBALGOPARA / SET LDCALGOPARA

Key parameters • UL (RTWP) LDR trigger threshold

D Parameter ID: ULLDRTRIGTHD


• UL (RTWP) LDR release threshold

a Parameter ID: ULLDRRELTHD


Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Pagel24 |P§ HUAWEI

UL LDR trigger threshold Parameter ID: ULLDRTRIGTHD Value range: 0 to 100 , % Content: If the UL load of the cell is not lower than this threshold, the UL load reshuffling function of the cell is triggered. The default value of this parameter is 55% Set this parameter through ADD CELLLDM/MOD CELLLDM

UL LDR release threshold Parameter ID: ULLDRRELTHD Value range: 0 to 100 , % Content: If the UL load of the cell is lower than this threshold, the UL load reshuffling function of the cell is stopped. The default value of this parameter is 45% Set this parameter through ADD CELLLDM / MOD CELLLDM

Key parameters • DL (TX POWER) LDR trigger threshold

a Parameter ID: DLLDRTRIGTHD

o The default value of this parameter is 70%

• DL (TX POWER) LDR release threshold

a Parameter ID: DLLDRRELTHD


. .::::::::::. •.-•:;:::::::: :: : : Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page125 WW H U A I W E I

DL LDR trigger threshold Parameter ID: DLLDRTRIGTHD Value range: 0 to 100, % Content: If the DL load of the cell is not lower than this threshold, the DL load reshuffling function of the cell is triggered. The default value of this parameter is 70% Set this parameter through ADD CELLLDM / MOP CELLLDM

DL LDR release threshold Parameter ID: DLLDRRELTHD Value range: 0 to 100, % Content: If the DL load of the cell is lower than this threshold, the DL load reshuffling function of the cell is stopped. The default value of this parameter is 60% Set this parameter through ADD CELLLDM / MOP CELLLDM

Key parameters • Cell LDR SF reserved threshold

a Parameter ID: CELLLDRSFRESTHD

p The default value of this parameter is SF8

• UI LDR Credit SF reserved threshold

u Parameter ID: ULLDRCREDITSFRESTHD

• The default value of this parameter is SFS

• Dl LDR Credit SF reserved threshold

n Parameter ID: DLLDRCREDITSFRESTHD

• The default value of this parameter is SF8

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page126 i P f HUAWEI

Cell LDR SF reserved threshold Parameter ID: CELLLDRSFRESTHD Value range: SF4, SF8, SF16, SF32, SF64, SF128, SF256 Content: If the SF corresponding to the current remaining code of the cell is higher than the threshold defined by this parameter, code congestion is triggered and the related handling actions are taken. The default value of this parameter is SF8 Set this parameter through ADD CELLLDR / MOD CELLLDR

UI LDR Credit SF reserved threshold Parameter ID: ULLDRCREDITSFRESTHD Value range: SF4, SF8, SF16, SF32, SF64, SF128, SF256 Content: If the SF corresponding to the current UL remaining credit resource is higher than the threshold defined by this parameter, the UL credit LDR can be performed and the related handling actions are taken. The default value of this parameter is 60% Set this parameter through ADD NOPEBLDR/MOD NODEBLDR

Dl LDR Credit SF reserved threshold Parameter ID: DLLDRCREDITSFRESTHD Value range: SF4, SF8, SF16, SF32, SF64, SF128, SF256 Content: If the value of SF corresponding to the current DL remaining credit resource is higher than the threshold defined by this parameter, the DL credit LDR can be performed and the related handling actions are taken. The default value of this parameter is SF8 Set this parameter through ADD NQDEBLDR/MOD NODEBLDR

Key parameters • The First / Second/ Third/ Fourth priority for load

a Parameter ID:

• LdrFirstPri

• LdrSecondPri

• LdrThirdPri

• LdrFourthPri

a The default configuration is :

. lUBLDR > CREDITLDR > CODELDR > UULDR


reshuffling

l i d HUAWEI

The First / Second/ Third/ Fourth priority for load reshuffling Parameter ID: LdrFirstPri / LdrSecondPri / LdrThirdPri / LdrFourthPri Value range: IUBLDR(lub load reshuffling), CREDITLDR(Credit load reshuffling), CODELDR (Code load reshuffling), UULDR (Uu load reshuffling) Content: These parameters specify the triggering resource order when congestion of all resources are triggered. The default configuration is lUBLDR > CREDITLDR > CODELDR > UULDR Set this parameter through SET LDCALGOPARA

LDR procedure

Turn on LDR algorithm switch

T Mark "current LDR state = uncongested1

Start LDM congestion indication report

Mark current action = first LDR action

Clear "selected" mark of all UE LDR actions Congestion

state indication J Wait for congestion indication

Current LDR state = congested?

Inter-freq oad handover

Code reshuffling

BE rate reduction Succeed?

Sequence of actions can be

configured (current action is taken firstly)

Inter-system handover

in CS domain Mark

"current action = successful

action"

Wait time for LDR

action duration Inter-system handover

In PS domain

AMR rate reduction Succeed?

QoS renogiation on Iu interface

MBMS power reduction

No related action can be found Mark current action first LDR action"

V,

Key parameters • LDR period timer length

a Parameter ID: LDRPERIODTIMERLE

D The default value of this parameter is 10 s

• Gold User Load Control Switch

a Parameter ID: GoldUserLoadControlSwitch

n The default value of this parameter is OFF


LDR period timer length Parameter ID: LDRPERIODTIMERLE Value range: 0 to 86400 s Content: This parameter specifies the period of load reshuffling . The default value of this parameter is 10 s Set this parameter through SET LDCPERIOD

Gold User Load Control Switch Parameter ID: GoldUserLoadControlSwitch Value range: ON, OFF Content: This parameter specifies whether LDR actions are applicable to users of gold priority. The default value of this parameter is OFF Set this parameter through ADD CELLLDR / MOP CELLLDR

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Key parameters • DL LDR first / second / third /fourth /fifth / sixth / seventh /

eighth / ninth / tenth action

a Parameter ID:

• DILdrFirstAction / DILdrSecondAction / DILdrThirdAction / DILdrFourthAction / DILdrFifthAction / DILdrSixthAction / DILdrSeventhAction / DlLdrEighthAction / DlLdrNinthAction / DILdrTenthAction

• The default configuration is :

. 1st:CODEADJ , 2nd: INTERFREQLDHO , 3rd: BERATERED

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page130 V w H U A W E I

DL LDR first/second/third/fourth/fifth/sixth/seventh/eighth/ninth/tenth action Parameter ID: DILdrFirstAction / DILdrSecondAction / DILdrThirdAction / DILdrFourthAction / DILdrFifthAction / DILdrSixthAction / DILdrSeventhAction / DlLdrEighthAction / DlLdrNinthAction / DILdrTenthAction Value range: NOACT (NO ACTION), INTERFREQLDHO (INTER-FREQ LOAD HANDOVER), BERATERED (BE TRAFF RATE REDUCTION), QOSRENEGO (UNCONTROLLED REAL-TIME TRAFF QOS RE-NEGOTIATION), CSINTERRATSHOULDBELDHO (CS DOMAIN INTER-RAT SHOULD BE LOAD HANDOVER), PSINTERRATSHOULDBELDHO (PS DOMAIN INTER-RAT SHOULD BE LOAD HANDOVER), AMRRATERED (AMR TRAFF RATE REDUCTION), MBMSDECPOWER(MBMS DESCEND POWER), CODEADJ(CODE ADJUST), CSINTERRATSHOULDNOTLDHO (CS DOMAIN INTER-RAT SHOULD NOT BE LOAD HANDOVER), PSINTERRATSHOULDNOTLDHO (PS DOMAIN INTER-RAT SHOULD NOT BE LOAD HANDOVER). Content: These parameters specify the LDR action order. The default configuration is 1st:CODEADJ , 2nd: INTERFREQLDHO , 3rd: BERATERED, Set this parameter through ADD CELLLDR / MOD CELLLDR / ADD NODEBLDR / MOP NODEBLDR

V^

LDR Actions • Inter-frequency load handover

n Target users c\ s • Based on user integrate priority

' ^ * A Xtfvôi

4 \

. Current bandwidth for DCH or "GBR bandwidth for HSPA" the UL/DL Inter-freq cell load handover maximum

• Target cells

has to be less than bandwidth parameter

• Load difference between current load and the basic congestion trigger threshold of target cell is larger than space threshold"

Copyright © 2009 Huawei Technologies Co., Ltd. All rights

"UL/DL Inter

reserved.

-freq cell load handover load

Page! 31 H H HUAWEI

implemented as follows: The LDR check whether the existing cell has a target cell of inter-frequency blind handover. If there is no such a target cell, the action fails, and the LDR performs the next action. The LDR checks whether the load difference between the current load and the basic congestion trigger threshold of each target cell for blink handover is larger than UL/DL Inter-freq cell load handover load space threshold (Both uplink and downlink condition must be all fulfilled). If the basic congestion trigger threshold is not set, the admission threshold of the cell is used. If the difference is not larger than the threshold, the action fails. The LDR performs the next action. If the LDR finds a target cell that meets the specified blind handover conditions, the LDR selects one UE to perform an inter-frequency blind handover to the cell according to the user integrate priority. For the selected UE, its UL/DL current bandwidth for DCH or GBR bandwidth for HSPA has to be less than the UL/DL Inter-freq cell load handover maximum bandwidth parameter (both the uplink and downlink conditions must be fulfilled). If there is more than one such UE, the one with the greatest bandwidth is taken. If the LDR cannot find such a UE, the action fails. The LDR performs the next action.

•

Key parameters • UL/DL Inter-freq cell load handover load space threshold

a Parameter ID: UL/DllnterFreqHoCellLoadSpaceThd


• InterFreq HO code used ratio space threshold

a Parameter ID: LdrCodeUsedSpaceThd


• UL/DL Inter-freq cell load handover maximum bandwidth

a Parameter ID: UL/DLINTERFREQHOBWTHD


Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Pagel 32 4 P w H U A W E I

UL/DL Inter-freq cell load handover load space threshold Parameter ID: UL/DLINTERFREQHOCELLLOADSPACETHD Value range: 0 to 100 % ,step:1% Content: The target cell can be a cell for inter-frequency blind handover only when the UL/DL load space is higher than the threshold. The UL/DL load space is the difference between the UL/DL basic congestion triggering threshold and the current UL/DL load of a target cell for blind handover.. The default value of this parameter is 20% Set this parameter through ADD CELLLDR / MOD CELLLDR

InterFreq HO code used ratio space threshold Parameter ID: LdrCodeUsedSpaceThd Value range: 0 to 100%,step:1% Content: The target cell can be used for inter-frequency blind handover only when the DL Code used ratio space is higher than the threshold. The DL Code used ratio space is the difference of code used ratio between the source cell and the target cell. The default value of this parameter is 13% Set this parameter through ADD CELLLDR / LST CELLLDR / MOD CELLLDR

UL/DL Inter-freq cell load handover maximum bandwidth Parameter ID: UL/DLINTERFREQHOBWTHD Value range: 0 to 400000 bps Content: During the inter-frequency load handover, the UE is selected as the target of inter-frequency load handover from the UE set where the bandwidth is less than this threshold. The default value of this parameter is 200000 Set this parameter through ADD CELLLDR / MOD CELLLDR

XK

LDR Actions « BE Rate Reduction

a Target RABs

• Based on RAB integrate priority

• The data rate of BE service is larger than GBR

• Number of RABs to be selected is configurable


BE rate reduction is implemented by reconfiguring the bandwidth. Bandwidth reconfiguration requires signaling interaction on the Uu interface.

The LDR algorithm is implemented as follows: 1. Based on the integrate priority, the LDR sorts the RABs into a descending order. The

top RABs related to the BE services (whose current rate is higher than its GBR configured by SET USERGBR command) are selected. If the integrate priorities of some RABs are identical, the RAB with the highest rate is selected. The number of RABs to select is determined by the UL/DL LDR-BE rate reduction RAB number parameter.

2. The bandwidth of the selected services is reduced to the specified rate. 3. If services can be selected, the action is successful. If services cannot be selected, the

action fails. The LDR takes the next action. 4. The reconfiguration is completed as indicated by the RB RECONFIGURATION

message on the Uu interface and through the RL RECONFIGURATION message on the Iub interface.

5. The BE rate reduction algorithm is controlled by the DCCC algorithm switch. BE rate reduction can be performed only when the DCCC algorithm is enabled.

Key parameters * UL /DL LDR-BE rate reduction RAB number

a Parameter ID: UL/DLLDRBERATEREDUCTIONRABNUM


: ::'• :: • ' "' " ' ' ": - •'--:.:•''•--•••• —-':•:•;;•• Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page134 J§# HUAWEI

UL /DL LDR-BE rate reduction RAB number Parameter ID: UL/DLLDRBERATEREDUCTIONRABNUM Value range: 1 to 10 Content: These parameters specify the number of RABs to select in a UL/DL LDR BE rate reduction. If the number of RABs that fulfil the criteria for BE rate reduction is smaller than the value of this parameter, then all the RABs that fulfil the criteria are selected. The default value of this parameter is 1 Set this parameter through ADD CELLLDR /MOD CELLLDR/ADD NODEBLDR/MOD NODEBLDR

LDR Actions « Uncontrolled Real-time service QoS Renegotiation

D Target RABs


• Real-time services in the PS domain

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page135 I U HUAWEI

The load is reduced by adjusting the rate of the real-time services through uncontrolled real-time OoS renegotiation.

Upon receipt of the message, the CN sends the RAB ASSIGNMENT REQUEST message to the RNC for RAB parameter reconfiguration. Based on this function, the RNC can adjust the rate of real-time services to reduce the load.

The LDR algorithm is implemented as follows: 1. Based on the integrate priority, the LDR sorts the real-time services in the PS domain in

descending order. The top services are selected for QoS renegotiation. 2. The LDR performs QoS renegotiation for the selected services. The GBR during

service setup is the rate of the service after QoS renegotiation. 3. The RNC initiates the RAB Modification Request message to the CN for QoS

renegotiation. 4. If the RNC cannot find a proper service for QoS renegotiation, the action fails. The LDR

performs the next action.

Key parameters » UL/DL LDR un-ctrlRTQos re-nego RAB num

a Parameter ID: UL/DLLDRPSRTQOSRENEGRABNUM


Copyright © 2009 Huawei Technologies Co., Ltd. Ail rights reserved. Paget 36 |f|| rlUAWEI

UL /DL LDR un-ctrl RT Qos re-nego RAB num Parameter ID: UL/DLLDRPSRTQOSRENEGRABNUM Value range: 1 to 10 Content: These parameters specify the number of RABs to select in a UL/DL LDR uncontrolled real-time QoS renegotiation. If the number of RABs that fulfil the criteria for uncontrolled real-time QoS renegotiation is smaller than the value of this parameter, then all the RABs that fulfil the criteria are selected. The default value of this parameter is 1 Set this parameter through ADD CELLLDR / MOD CELLLDR/ADD NODEBLDR/MOD NODEBLDR

LDR Actions • Inter-system Handover In the CS/PS Domain

n Target user

• Based on the user integrate priority

• Handover Indicator - "Handover to GSM should be performed"

- "handover to GSM should not be performed"

GSM cell

WCDMA ce

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Paget 37 HUAWEI

The 2G and 3G systems have different cell sizes and coverage modes. Therefore, blind handover across systems is not taken into account.

The LDR is implemented in the downlink (e.g.) as follows: 1. Based on the integrate priority, the LDR sorts the UEs in descending order. The top

CS/PS services are selected. 2. For the selected UEs, the LDR sends the load handover command to the inter-system

handover module to ask the UEs to hand over to the 2G system. 3. The handover module decides to trigger inter-system handover, depending on the

capability of the UE and the capability of the algorithm switch to support the compression mode.

4. This action is successful if any load handover UE is found. Otherwise, this action fails.

Key parameters • UL/DL CS should be ho user number

n Parameter ID: UL/DLCSINTERRATSHOULDBEHOUENUM


# UL/DL CS should not be ho user number

a Parameter ID: UL/DLCSINTERRATSHOULDNOTBEHOUENUM



UL / DL CS should be ho user number Parameter ID: UL/DLCSINTERRATSHOULDBEHOUENUM Value range: 1 to 10 Content: These parameters specify the number of users to select in a UL/DL Inter-RAT Should Be Load Handover in the CS Domain. If the number of users that fulfil the criteria for Inter-RAT Should Be Load Handover in the CS Domain is smaller than the value of this parameter, then all the users that fulfil the criteria are selected. The default value of this parameter is 3 Set this parameter through ADD CELLLDR / MOD CELLLDR/ADD NODEBLDR/MOD NODEBLDR

UL / DL CS should not be ho user number Parameter ID: UL/DLCSINTERRATSHOULDNOTBEHOUENUM Value range: 1 to 10 Content: These parameters specify the number of users to select in a UL/DL Inter-RAT Should Not Be Load Handover in the CS Domain. If the number of users that fulfil the criteria for Inter-RAT Should Not Be Load Handover in the CS Domain is smaller than the value of this parameter, then all the users that fulfil the criteria are selected. The default value of this parameter is 3 Set this parameter through ADD CELLLDR / MOD CELLLDR/ADD NODEBLDR/MOD NODEBLDR

•.;•••••;•".'."•'• '':':•':'• '"' "•'"" • ...•,•.•••,•••: .* ••••• • -•••••-••• -Page138 I p f HUAWEI

Key parameters • UL/DL PS should be ho user number

D Parameter ID: UL/DLPSINTERRATSHOULDBEHOUENUM


• UL/DL PS should not be ho user number

a Parameter ID: UL/DLPSINTERRATSHOULDNOTBEHOUENUM


Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page139 H i H U A W E I

UL / DL PS should be ho user number Parameter ID: UL/DLPSINTERRATSHOULDBEHOUENUM Value range: 1 to 10 Content: These parameters specify the number of users to select in a UL/DL Inter-RAT Should Be Load Handover in the PS Domain. If the number of users that fulfil the criteria for Inter-RAT Should Be Load Handover in the PS Domain is smaller than the value of this parameter, then all the users that fulfil the criteria are selected. The default value of this parameter is 1 Set this parameter through ADD CELLLDR/ MOD CELLLDR/ADD NODEBLDR/MOD NODEBLDR

UL / DL PS should not be ho user number Parameter ID: UL/DLPSINTERRATSHOULDNOTBEHOUENUM Value range: 1 to 10 Content: These parameters specify the number of users to select in a UL/DL Inter-RAT Should Not Be Load Handover in the PS Domain. If the number of users that fulfil the criteria for Inter-RAT Should Not Be Load Handover in the PS Domain is smaller than the value of this parameter, then all the users that fulfil the criteria are selected. The default value of this parameter is 1 Set this parameter through ADD CELLLDR/ MOD CELLLDR/ADD NODEBLDR/MOD NODEBLDR

LDR Actions « AMR Rate Reduction

• Target user

AMR services and with the bit rate higher than the GBR

Based on RAB integrate priority

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page140 W H U A W E I

In the WCDMA system, voice services work in eight AMR modes. Each mode has its own rate. Therefore, mode control is functionally equal to rate control.

The LDR algorithm is implemented as follows: 1. Based on the integrate priority, the LDR sorts the RABs in the descending order. The top

UEs accessing the AMR services (conversational) and with the bit rate higher than the GBR are selected.

2. In uplink, the RNC sends the "Rate Control request" message through the lu-UP to the CN to adjust the AMR rate to the GBR.

3. In downlink, The RNC sends the TFC CONTROL command to the UE to adjust the AMR rate to the assured rate.

4. If the RNC cannot find a proper service for AMR rate reduction, the action fails. The LDR performs the next action.

Key parameters # UL/DL LDR-AMR rate reduction RAB number

D Parameter ID: UL/DLLDRAMRRATEREDUCTIONRABNUM


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UL/DL LDR-AMR rate reduction RAB number Parameter ID: UL/DLLDRAMRRATEREDUCTIONRABNUM Value range: 1 to 10 Content: These parameters specify the number of RABs to select in a UL/DL LDR AMR rate reduction. If the number of RABs that fulfil the criteria for AMR rate reduction is smaller than the value of this parameter, then all the RABs that fulfil the criteria are selected. The default value of this parameter is 3 Set this parameter through ADD CELLLDR / MOD CELLLDR

LDR Actions « Code Reshuffl ing

n Reallocate code resources for candidate user

a Code Adjustment

*» Figure 1 Code tree fee-ore case- wi'ru^v.-.y

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Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved.

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Page142 HUAWEI

The algorithm operates as follows: 1,Initialize the SF_Cur of the root node of subtrees to Cell LDR SF reserved threshold. 2,Traverse all the subtrees with this SF_Cur at the root node. Leaving the subtrees

occupied by common channels and HSDPA channels out of account, take the subtrees in which the number of users is not larger than the value of the Max user number of code adjust parameter as candidates for code reshuffling.

3,Select a subtree from the candidates according to the setting of the LDR code priority indicator parameter.

If this parameter is set to TRUE, select the subtree with the largest code number from the candidates.

» If this parameter is set to FALSE, select the subtree with the smallest number of users from the candidates. In the case that multiple subtrees have the same number of users, select the subtree with the largest code number.

4,Treat each user in the subtree as a new user and allocate code resources to each user. 5,Initiate the reconfiguration procedure for each user in the subtree and reconfigure the

channel codes of the users to the newly allocated code resources. The reconfiguration procedure on the air interface is implemented through the PHYSICAL

CHANNEL RECONFIGURATION message and that on the Iub interface through the RL RECONFIGURATION message.

Key parameters • Max user number of code adjust

a Parameter ID: MAXUSERNUMCODEADJ


• LDR code priority indicator

a Parameter ID: LdrCodePriUselnd

n The default value of this parameter is False

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Max user number of code adjust Parameter ID: MAXUSERNUMCODEADJ Value range: 1 to 3 Content: This parameter specifies the maximum number of users that can be selected whenever code reshuffling is performed. The default value of this parameter is 1 Set this parameter through ADD CELLLDR / MOD CELLLDR

LDR code priority indicator Parameter ID: LdrCodePriUselnd Value range: True, False Content: This parameter specifies whether to select preferentially the subtree with a relatively large code number during subtree selection. Set this parameter through ADD CELLLDR / MOD CELLLDR

LDR Actions • MBMS Power Reduction

a Purpose

• The downlink power load can be reduced by lowering power on MBMS traffic channels

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The LDR algorithm is implemented as follows: 1. Select all RABs with low priorities. 2. The RNC initiates the reconfiguration procedure and resets the transmit power of

MTCH (FACH) to the minimum value. The transmit power corresponds to the MBMS service.

3. The reconfiguration procedure on the Iub interface is implemented through the COMMON TRANSPORT CHANNEL RECONFIGURATION REQUEST message.

§: Contents 2. Load Control Algorithms



2.3 CAC {Call Admission Controi)




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Over Load Control • Reasons

o In overload state, system is not stable

• Purpose

a Ensuring the system stability and making the system back to the normal state as soon as possible

• Triggering of Over Load

a Power resource

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After the UE access is granted, the power consumed by a single link is adjusted by the single link power control algorithm. The power varies with the mobility of the UE and the changes in the environment and the source rate. In some situations, the total power load of the cell may be higher than the target load. To ensure system stability, overload congestion must be handled.

Over Load Control Over Load triggering

UL/DL load k

OLC Trigger threshold

OLC Release threshold

r /-**—m j

/

__.Cell in overload congestion _

— i u 1 tr

Overload congestion released

V f 4 4 time""

RNC periodic check

——*- State Trans Hysteresis threshold

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If the current UL/DL load of an R99 cell is not lower than the UUDL OLC Trigger threshold for some hysteresis (defined by the DL State Trans Hysteresis threshold in DL; not configurable in UL), the cell works in overload congestion state and the related overload handling action is taken. If the current UL/DL load of the R99 cell is lower than the UL/DL OLC Release threshold for some hysteresis (defined by the DL State Trans Hysteresis threshold in DL; not configurable in UL), the cell comes back to the normal state. The HSPA cell has the same uplink decision criterion as the R99 cell. The load in the downlink, however, is the sum of load of the non-HSPA power (transmitted carrier power of all codes not used for HS-PDSCH or HS-SCCH transmission) and the GBP..

Key parameters • Cell LDC algorithm switch

a Parameter ID: NBMLDCALGOSWITCH

. UL_UU_OLC, DL_UU_OLC

• UL/DL OLC trigger threshold

D Parameter ID: UL/DLOLCTRIGTHD


• UL/DL OLC release threshold

a Parameter ID: UL/DLOLCRELTHD


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Cell LDC algorithm switch Parameter ID: NBMLDCALGOSWITCH Value range: OFF, ON Content: This parameter specifies the switch of UL/DL OLC. UL_UU_OLC: UL overload control algorithm DL_UU_OLC: DL overload control algorithm Set this parameter through ADD CELLALGOSWITCH / MOD CELLALGOSWITCH

UL/DL OLC trigger threshold Parameter ID: UL/DLOLCTRIGTHD Value range: 0 to 100% Content: If the UL load of the cell is not lower than the value of the UL OLC trigger threshold, the UL overload congestion control of the cell is activated. If the DL load of the cell is not lower than the value of the DL OLC trigger threshold, the DL overload congestion control of the cell is activated. Set this parameter through ADD CELLLDM / MOD CELLLDM

UL/DL OLC release threshold Parameter ID: UL/DLOLCRELTHD Value range: 0 to 100% Content: If the UL load of the cell is lower than the value of the UL OLC release threshold, the UL overload congestion control of the cell is deactivated. If the DL load of the cell is lower than the value of the D«L OLC release threshold, the DL overload congestion control of the cell is deactivated. Set this parameter through ADD CELLLDM / MOD CELLLDM

Turn on OLC algorithm switch

I Mark "current OLC state = un congested"

Start OLC congestion indication report

1 Mark "current action = first OLC action"

I Clear the "selected" mark of all UE OLC actions

Congestion state indicatio ¥ I

Wait for congestion state indication

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Sequence factions

cannot be configured

(current action is

taken firstly)

=-c^purrerit OLC state = conge^rtetTr^z^-

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Channel switching of BE

service

Jl

-"" Succeed?

Releasing of Succeed?

Send congestion release indication to MAC (downlink

congestion)

7 N

Mark "current action = success-ful action"

Wait time for

"OLC action timer'

$ r

No related action can be found. Mark "current action = first OLC action"

The general OLC procedure covers the following actions: TF control of BE services, channel switching of BE services, and release of RABs. The RNC takes periodical actions if overload congestion is detected.

When the cell is overloaded, the RNC takes one of the following actions in each period (defined by the OLC period timer length parameter, e.g.3s) until the congestion is resolved:

1. TF control of BE service (only for DCH BE service) 2. Switching BE services to common channel 3. Choosing and releasing the RABs (for HSPA or DCH service)

If the first action fails or the first action is completed but the cell is still in congestion, then the second action is taken.

Key parameters OLC period timer length

a Parameter ID: OLCPERIODTIMERLEN

D The default value of this parameter is 3000 (ms)

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OLC period timer length Parameter ID: OLCPERIODTIMERLEN

A # •> ' Value range: 100 to 86400000 Content: This parameter specifies the period of overload control. The default value of this parameter is 3000 (ms) Set this parameter through SET LDCPERIOD

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OLC Action • TF Control

n Target user


• The RABs with the DCH BE services

n Execution

• The RNC sends the "TF control indication" message to the MAC.

• MAC restricts the TFC selection : maximum TB number - TFmax(N+1) = TFmax(N) x Ratelimitcoeff

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Based on the RAB integrate priority, the OLC sorts the RABs into a descending order. The following RABs are selected:

The RABs with the DCH BE services The RABs with the lowest integrate priority.

The number of RABs selected is DL/UL OLC fast TF restrict RAB number.

In downlink, The RNC sends the TF control indication message to the MAC. Each MAC of selected RABs will receive one TF control indication message and will restrict the TFC selection (from TFCS) of the BE services to reduce the data rate step by step.

MAC restricts the TFC selection in a way like that the maximum TB number is calculated with the formula: TFmax(N+1) = TFmax(N) x Ratelimitcoeff where:

TFmax(O) is the maximum TB number of the BE service before the service is selected for TF control.

TFmax(N+1) is the maximum TB number during time TO+RateRstrctTimerLen* (N) to TO+RateRstrctTimerLen* (N+1), where TO is the time MAC receiving the TF control indication message. RateRstrctTimerLen is a configurable parameter (DL TF rate restrict timer length) .

Ratelimitcoeff is a configurable parameter (DL OLC fast TF restrict data rate restrict coefficient).

If the RNC cannot find an appropriate service for the TF control or the time for performing the TF control exceed the DL OLC fast TF restrict times parameter, the action fails. The OLC performs the next action. If the congestion is released, the RNC sends the congestion release indication to the MAC. At the same time, the rate recovery timer (whose length is defined by DL OLC fast TF restrict data rate recover timer length) is started. When this timer is expired, the MAC increases the data rate step by step. MAC restricts the TFC selection by calculating the maximum TB number with the formula: TFmax(N+1) = TFmax(N) x RateRecoverCoeff where:

TFmax(O) is the maximum TB number of the BE service before congestion release indication is received.

TFmax(N+1) is the maximum TB number during time T1+ RateRecoverTimerLen * (N) to T1+RateRecoverTimerLen* (N+1), where T1 is the time MAC receiving congestion release indication message. RateRecoverTimerLen is a configurable parameter (DL TF rate recover timer length).

RateRecoverCoeff is a configurable parameter (DL TF rate recover coefficient).

In the Uplink For a UE accessing the DCH service, the RNC, in compliance with the 3GPP TS25.331, restricts the

TFC of the UE by sending the TRANSPORT FORMAT COMBINATION CONTROL message to the UE , UE does not have any response if the procedure can be performed successfully.

The number of RABs to select is defined by the UL OLC fast TF restrict RAB number parameter.

UE UTRAN

TRANSPORT FORMAT COMBINATION CONTROL

The TRANSPORT FORMAT COMBINATION CONTROL message contains the following lEs: Transport Format Combination Set Identity: defines the available TFC that the UE

can select, that is, the restricted TFC sub-set. It is always the two TFCs corresponding to the lowest data rate.

TFC Control duration: defines the period in multiples of 10 ms frames for which the restricted TFC sub-set is to be applied. It is set to a random value from the range of 10 ms to 5120 ms, so as to avoid data rate upsizing at the same time.

After the TFC control duration is due, UE can apply any TFC of TFCS before the TF control.

Each UE of selected RABs will receive the TRANSPORT FORMAT COMBINATION CONTROL message. How many times TF control is performed is defined by the UL OLC fast TF restrict times parameter.

If the RNC cannot find an appropriate service, the OLC performs the next action.

< — ^

OLC Action e ^ • TF Control example

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Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Pagel54 HUAWEI

Before point A, the cell is not in OLC state. The downlink data transfer rate is 384 kbit/s, the corresponding TF is 12 x 336, and TFS is {12 x 336, 8 x 336,4 x 336, 2 x 336, 1 x 336, 0 x 336}.336 is the TB size, 320 payload + 16 MAC head

At point A, the cell enters OLC state. The RNC selects this RAB to do fast TF restriction. MAC restricts the TFC selection during time between point A and point B by calculating the maximum TB number as follows: TFmax(1) = TFmax(O) x Ratelimitcoeff = 12 x 0.68 = 8.16 Match 8.16 and the TFS. Therefore, the maximum TB number is 8.

At point B, MAC performs further TFC restriction by calculating maximum TB number as follows: TFmax(2) = TFmax(1) x Ratelimitcoeff = 8 x 0.68 = 5.44 Match 5.44 and the TFS. Then, the maximum TB number is 4.

At point C and point D, similar process is followed.

Key parameters • UL/DL OLC fast TF restrict RAB number

a Parameter ID: U17DL0LCFTFRSTRCTRABNUM


• UL/DL OLC fast TF restrict times

a Parameter ID: UL/DLOLCFTFRSTRCTTIMES


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UL/DL OLC fast TF restrict RAB number Parameter ID: UL/DLOLCFTFRSTRCTRABNUM Value range: Oto 10 Content: These parameters specify the maximum number of RABs selected in a fast TF restriction of UL/DL OLC. If the number of RABs that fulfil the criteria for TF control is smaller than the value of this parameter, then all the RABs that fulfil the criteria are selected. The default value of this parameter is 3 Set this parameter through ADD CELLOLC / MOD CELLOLC

UL/DL OLC fast TF restrict times Parameter ID: UL/DLOLCFTFRSTRCTTIMES Value range: Oto 100 Content: These parameters specify the times of UL/DL OLC fast TF restrictions that are executed. The default value of this parameter is 3 Set this parameter through ADD CELLOLC / MOD CELLOLC

Key parameters * DL TF rate restrict coefficient

a Parameter ID: RateRstrctCoef


• DL TF rate restrict timer length

D Parameter ID: RateRstrctTimerLen

n The default value of this parameter is 3000 (ms)

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DL TF rate restrict coefficient Parameter ID: RateRstrctCoef Value range: 1 to 99 % Content: This parameter specifies the data rate restriction coefficient in the fast TF restriction. The smaller the parameter is, the more effective the TF restriction is. After receiving the TF control indication, the MAC obtains the maximum TF format with the formula TFmax' = TFmax x Ratelimitcoeff. The default value of this parameter is 68 % Set this parameter through ADD CELLOLC / MOD CELLOLC

DL TF rate restrict timer length Parameter ID: RateRstrctTimerLen Value range: 1 to 65535 ms Content: This parameter specifies the length of the data rate restriction timer in the fast TF restriction. The smaller the value of this parameter is, the more effective the TF restriction is. The default value of this parameter is 3000 ms Set this parameter through ADD CELLOLC / MOD CELLOLC

Key parameters » DL TF rate recover timer length

n Parameter ID: RateRecoverTimerLen

D The default value of this parameter is 5000 (ms)

• DL TF rate recover coefficient

a Parameter ID: RecoverCoef

• The default value of this parameter is 130 %

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DL TF rate recover timer length Parameter ID: RateRecoverTimerLen Value range: 1 to 65535 ms Content: This parameter specifies the length of the data rate recovery timer. The smaller the value of this parameter is, the faster the BE traffic rate increases after the congestion is resolved. The default value of this parameter is 5000 ms Set this parameter through ADD CELLOLC / MOD CELLOLC

DL TF rate recover coefficient Parameter ID: RecoverCoef Value range; 100 to 200 % Content: This parameter specifies the data rate recovery coefficient in the fast TF restriction. The larger the parameter is, the larger the TF recover effect. After receiving congestion release indication, the MAC obtains the maximum TF format with the formula TFmax' = TFmax x RateRecoverCoeff. The default value of this parameter is 130% Set this parameter through ADD CELLOLC / MOD CELLOLC

OLC Action • Switching BE Services to Common Channel

p Target user

• Based on the user integrate priority

• The users with the DCH or HSDPA BE services in PS

n Execution

• The RNC sends "RB Reconfiguration" message to UE

• UE make a response by "RB Reconfiguration Complete"

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The OLC algorithm for switching BE services to common channel operates as follows: Based on the user integrate priority, the OLC sorts all UEs that only have PS services

including HSPA and DCH services (except UEs having also a streaming bearer) into a descending order.

The top N UEs are selected. The number of selected UEs is equal to Transfer Common Channel user number. If UEs cannot be selected, the action fails. The OLC performs the next action.

The selected UEs are switched to common channel.

Key parameters • Transfer Common Channel User number

a Parameter ID: TransCchUserNum


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Transfer Common Channel User number Parameter ID: TransCchUserNum Value range: 1 to 10 Content: This parameter specifies the transfer common channel user number The default value of this parameter is 1 Set this parameter through ADD CELLOLC / MOD CELLOLC

OLC Action • Release of Some RABs

D Target user

• Based on the RAB integrate priority

• DCH services RAB

n Execution

• The RNC sends "IU Release Request" message to CN

• The RNC sends "RRC Connection Release" message to UE

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OLC Algorithm for the Release of Some RABs in the Uplink: The OLC algorithm for the release of some RABs in the uplink operates as follows: Based on the integrate priority, the OLC sorts all RABs including HSUPA and DCH services

into a descending order. The top RABs selected. If the integrate priorities of some RABs are identical, the RAB with

higher rate (current rate for DCH RAB and GBR for HSUPA RAB) in the uplink is selected. The number of selected RABs is equal to UL OLC traff release RAB number.

The selected RABs are released directly. OLC Algorithm for the Release of Some RABs in the Downlink The OLC algorithm for the release of some RABs in the downlink operates as follows: Based on the integrate priority, the OLC sorts all RABs into a descending order. The top-priority RABs are selected. If the integrate priorities of some RABs are identical,

the RAB with higher rate (current rate) The number of selected RABs is equal to DL OLC traff release RAB number.

The selected RABs are directly released.

Key parameters • UL/DL OLC traff release RAB number

u Parameter ID: UL/DLOLCTRAFFRELRABNUM


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UL/DL OLC traff release RAB number Parameter ID: UL/DLOLCTRAFFRELRABNUM Value range: Oto 10 Content: Either parameter specifies the number of RABs released in a UL or DL OLC release action. If the number of RABs that fulfil the criteria for release is smaller than the value of this parameter, then all the RABs that fulfil the criteria are selected. The default value of this parameter is 0 Set this parameter through ADD CELLOLC / MOD CELLOLC

) Summary Load Control Algorithms

PUC (Potential User Control)

LDB (Intra-Frequency Load Balancing)

CAC (Call Admission Control)

IAC (Intelligent Admission Control)

LDR (Load Reshuffling)

OLC (Overload Control)

':::;.;•;•:..:::•••••• - ./ •. •- • ' . ' ' • ••:: :.-. . Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page162

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Documents

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