Siemens Parameters Training

7/30/2019 Siemens Parameters Training

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By:

H.Bahmani

Dec.2011


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o BR8.0 OBJECT TREE OF BSC DATABASE OBJECTS

o BSC COMMANDS AND PARAMETERS (Dump)

o Channel Configuration

o Hierarchical Cell Structure

o Interference Reduction

o Radio Link Failure

o Some Major Siemens Parameters


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Database Tree of Parameters


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Database Tree of Parameters


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DUMP Structure

SET MELSET BSCSET BSCE

CREATE QSTHRSCREATE GBIPLNKCREATE LICDSCREATE CPCU

CREATE PCUCREATE NSVLIPCREATE PCMBCREATE PCMS

CREATE TRAUCREATE LPDLSSET TSLA

CREATE PCMACREATE SUBTSLBCREATE BTSCREATE CHAN

SET TRXCREATE ADJCCREATE SS7LCREATE SCAN


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Channel Configuration

o Channel Configuration Overview

o Control Channel Configuration

o Dedicated Channels

o Random Access Channels

o Paging/Access Channels & Notification Channels

o Extended Channel Mode

o

AMR


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Channel Configuration Overview

On the radio interface Um 2 subbands for the MS-BTS

Duplex connection is defined:


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Channel Organization in a cell


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Combined-BCCH


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Non-Combined-BCCH


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Control Channel Configuration


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Channel ConfigurationControl Channel Configuration: Dedicated Channels


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- Smooth Channel Modification (Dynamic TCH/SDCCH)


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- RF Pool Concept (Pooling TCH/SDCCH)


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- RF Pool Concept (Pooling TCH/SDCCH)


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- SDCCH Allocation Strategy


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- SDCCH Release Strategy


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- TCH Allocation/Release Strategy


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Random Access Channel


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Random Access Channel


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Random Access Channel: RACH Parameters

RACHBT=RACH busy threshold, defines a threshold for the signal level on

the RACH. The general purpose of this parameter is to define a minimum

level criterion a received RACH signal must fulfill to be regarded as a real

RACH access.

RACHBT=109,

object: BTS [BASICS]

unit: -1dBm

range: 0..127

default: 109


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Channel ConfigurationRandom Access Channel: RACH Parameters

MAXRETR= Maximum number of retransmissions, this parameterdefines the maximum number of retransmission attempts the MS can performon the RACH if the previous attempts have been unsuccessful. To request adedicated control channel (normally an SDCCH) from the network, the MSperforms a RACH access by sending a CHANNEL REQUEST message to theBSS via the RACH. In the successful case, the MS receives an IMMEDIATE

ASSIGNMENT COMMAND via the AGCH. The MS regards an access attempt unsuccessful when it has neither received an

IMMEDIATE ASSIGNMENT COMMAND or - if no SDCCH is available in thecell - an IMMEDIATE ASSIGNMENT REJECT via the AGCH before the timedefined by the parameter NSLOTST (see below) has expired.

MAXRETR=FOUR,

object: BTS [CCCH]

range: ONE, TWO, FOUR,

SEVEN

default: FOUR

Reference: GSM 04.08

GSM 05.08


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Channel ConfigurationRandom Access Channel: RACH Parameters

NSLOTST=Number of slot spread transmission, determines the cycleperiod for retransmission of RACH accesses (i.e. transmission of a

CHANNEL REQUEST message), i.e. it determines the time an MS must wait

after a RACH access attempt before a new one can be started. In the

mobile the retransmission mechanism is continuously executed after the

first RACH access and only stopped if an IMMEDIATE ASSIGNMENTCOMMAND or (if no SDCCH is available) an IMMEDIATE ASSIGNMENT

REJECT message is received from the BSS via the AGCH.

NSLOTST=10,

object: BTS [CCCH]

range: 0..15

default: 10

Reference: GSM 04.08


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Channel ConfigurationRandom Access Channel: Immediate Assignment Procedure


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Paging/Access Grant Channels


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Extended Channel Mode


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Adaptive Multi Rate (AMR)


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Adaptive Multi Rate (AMR: Parameters)


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BSS o Measurement Parameterso Access Related Parameters

o Cell Selection/Reselection Parameters

o Frequency Hopping Parameters

o Power Control Parameterso Handover Parameters

o Paging Parameters

o Radio Link Control

o DTX Parameters

o Hierarchical Cell Structure Parameters

o Radio Resource Timers (GSM Timers)

o


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BSS Measurement Parameters

The parameters are used for averaging and reporting interference levels inidle traffic channels.

INTAVEPR=1..31, Averaging period for idle TCH measurements, definesthe number of SACCH multiframes (480ms = 4 multiframes, theinterleaving

function distributes the SACCH info over 4 bursts) over which values areaveraged (value 1..31).

PAVRLEV= 4-2, Power control averaging parameters level, defines theaveraging parameters for the RXLEV measurements.

HOAVELEV=8-2, Handover averaging parameters for level handover, thisparameter defines the size of the gliding averaging window and the DTXweighting factor for the uplink and downlink RXLEV measurements forlevel handovers.

HOAVPWRB=8, Handover averaging window for power budget handover,defines the size of the size of the averaging window for downlink RXLEVvalues of the serving cell


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BSS Access Related Parameters

The parameters are used to control access of MS to the network.

MAXRETR=FOUR, Maximum number of retransmissions, this parameterdefines the maximum number of retransmission attempts the MS can

perform on the RACH if the previous attempts have been unsuccessful.

CELLBARR=FALSE, Cell barred, the value TRUE indicates that the cellis barred and camping or any other access to the cell is forbidden.

CREALL=NOTALLOWED, Call re-establishment allowed, indicateswhether the MS may try to start a Call re-establishment procedure.

NBLKACGR=1,Number of blocks for access grant, specifies the numberof CCCH blocks to be reserved in each configured CCCH timeslot for theAccess Grant Channel (AGCH) during a period of 51 TDMA frames, i.e.one multiframe.

RXLEVAMI=6, Minimum received level at the MS required for access tothe network on the RACH.


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BSS Cell Selection/Reselection Parameters

The parameters are used to control cell Selection/Reselectionof MS to the network.

CELLRESH=2, Cell reselect hysteresis, indicates the value of

the receiver RF power level hysteresis required for cellreselection (MS in idle mode) on the basis of the path losscriterion C1.

CRESOFF=1, This parameter is one of the necessary inputvalues for the calculation of C2. It applies an offset to the cellreselection criterion C2.

TEMPOFF=1, It applies a negative offset to C2 for theduration of the penalty time.

CRESPARI=1, indicates the presence of C2 cell reselectionparameters on the BCCH.


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BSS Frequency Hopping Parameters

HOPMODE=BBHOP, Hopping Mode, this parameterindicates whether baseband hopping or synthesizer hopping isto be used in this cell.

HOPP=TRUE, Frequency hopping enabled, indicates whetherfrequency hopping is manually enabled in the BTS by theoperator.

MAIO=0, Mobile allocation index offset. HSN=10, Hoppingsequence number, determines the hopping sequence.respective algorithm.

MOBALLOC=CALLF01&CALLF02&..., Mobile allocationlist, this parameter defines is a list of those cell allocationfrequencies used in the hopping sequence.


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BSS Power Control Parameters

PWRRED=6, Power reduction, specifies the number of 2-dB-stepsthe Tx power should be reduced from the maximum transmit power.

PWRINCSS=DB6, Power increase step size, defines the step sizeused when increasing the MS transmit power.

PWREDSS=DB2, Power reduction step size, defines the step size

used when reducing the MS transmit power. EMSPWRC= ADAPTIVE, Enable MS power control, determines

whether the BTS instructs the MS to dynamically adjust its sendingpower according to the current radio conditions. MS Power Controlis used to save MS battery capacity and to minimize the uplinkinterference on the radio interface.

EBSPWRC=ADAPTIVE, Enable BS power control, determineswhether the BTS dynamically adjusts its sending power according tothe current radio conditions (on non-BCCH carriers). Enabling BSPower Control results in a minimization of the downlink interferenceon the radio interface.

BSS


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BSS Handover Parameters

HOM=69, Handover margin, this parameter defines a threshold for thepower budget handover.

RXQUALHO=TRUE, RxQual handover enabled, determines whetherhandover due to bad receive quality on uplink or downlink is enabled.

RXLEVHO=TRUE, RxLevel handover enabled, determines whetherhandover due to low receive level on uplink or downlink is enabled.

PBGTHO=TRUE, Power budget handover enabled, determines whetherhandover due to power budget is enabled.

DISTHO=TRUE, Distance Handover enabled, determines whetherhandover due to long distance between MS and BTS is enabled.

NOBAKHO=TRUE, No back handover, this flag determines whether thefeature Prevention of Backhandovers is enabled or not.

RXLEVMIN=12, Rx level minimum, determines the minimum receivedsignal level the adjacent cell must provide to be regarded as a suitable targetcell for handover. It is the minimum Rx level required for a MS to performthe handover to the adjacent cell.

BSS


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BSS Paging Parameters

NFRAMEPG=2, Number of multiframes between paging, definesthe number of multiframes (51 TDMA frames) between twotransmissions of the same paging message to mobiles of the same.paging group. The paging group determines which CCCH blocks theMS shall monitor for incoming paging messages. By just monitoringa subset of the CCCH blocks for paging (Discontinuous Reception(DRX)) the MS can save battery capacity.

IMSIATDT=TRUE, If this parameter is set to TRUE the MSs arerequested by the above mentioned BCCH parameter to send an .IMSIAttach. message when they are switched on respectively an .IMSIDetach. message when they are switched off.

NBLKACGR=1, Number of blocks for access grant, specifies thenumber of CCCH blocks to be reserved in each configured CCCHtimeslot for the Access Grant Channel (AGCH) during a period of 51TDMA frames, i.e. one multiframe.

BSS


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BSS Radio Link Control Parameters

RDLNKTO=4, Radio link timeout, the value entered for

this parameter determines the value of the parameter

RADIO_LINK_TIMEOUT is used by the MS to calculate

the maximum value of the radio link counter (.S. counter)in the MS which is needed to detect a radio link failure in

the downlink.

BSS


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0BSS DTX Parameters DTXDLFR=FALSE, Discontinuous transmission

downlink for FR calls enabled, specifies whether.discontinuous transmission downlink (DTX downlink). isenabled for FR calls in the BTS.

DTXDLHR=FALSE, Discontinuous transmissiondownlink for HR calls enabled, specifies whetherdiscontinuous transmission (DTX) is enabled for HR callsin the BTS

DTXUL=SHLFSHNH, Discontinuous transmissionuplink enabled, specifies whether discontinuoustransmission (DTX) shall be used by the MS.

BSS


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Radio Resource Timers Many radio resource timers exist in GSM.

Generally speaking, their main purpose is

to ensure de-allocation of radio resourcesafter the failure of some resource

allocation process,

And thus ensure maximum utilization and

minimum wastage of resources.

1BSS


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Radio Resource Timers-1

1) T3111 =HLFSEC-1,

This timer is used during the normal layer 2 channel release procedure. Its purpose is to

maintain the dedicated channel in an active state long enough for the MS to repeat the L2

DISC message if required.

T3111 commences when the first DISC is received by the BSS, and up to 5 repetitions of the

DISC are allowed, at intervals of T200 (235ms on SDCCH, 166ms on FACCH). This means

that the maximum time that the dedicated channel needs to be held is 1175ms (5 x 235ms). Ahigher setting of rr_t3111 will hold SDCCH or TCH resources longer than necessary, possibly

introducing SDCCH or TCH congestion.

A lower setting could result in two mobile stations being active on the same channel. To avoid

the possibility of 2 mobile stations active on the same channel and to safely minimize channel

usage, it is recommended that T3111 be set to 1200ms across all cells (Aircom

recommendation).

object: BTS [TIMER]

units: MS100 = 100 ms

HLFSEC = 0,5 sec

SEC5 = 5s

range: 0..255

default: HLFSEC-1

T3111

purpose: security period for acknowledgement of the main signaling link

disconnection

start: receipt of the RELEASE INDICATION message

expiryaction: sending of the RF CHANNEL RELEASE message


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2) T3212=10, timer for periodic location update, A recovery in the VLR normally leads to the loss of the subscriber data. Periodic location update is used to ensure

the continuous update of subscriber data in the VLR even if the subscriber remains in the same location area.

This timer is reset to 0 and started when a signaling activity has taken place on the radio path (e.g. Location update,

MOC, IMSI Attach). When the MS is powered down the current value of T3212 is kept in memory. When the MS

is powered up the timer starts running from the value thus contained in memory. On expiry the MS initiates a

location updating.

This parameter is sent on the BCCH (SYSTEM INFORMATION TYPE 3) in the IE .Control Channel Description. If the IMSI detach feature is enabled this timer should be set to a value less than the MSC/VLR implicit

detach timer.

If the setting is vice versa, the MS may be set to .detached. in the VLR even before it executes a Periodic Location

Update.

The effect of this timer change will be to improve the mobile terminated call set up success rate measuredby the MSC and perceived by anybody trying to call a mobile station from either the fixed network oranother mobile station.

object: BTS [OPTIONS]

unit: 1 decihour (6 min)

range: 0..255

0 means .infinite timeout., i.e. periodic loc. Updating is used in the cell..

default: 10 = 60 min.


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3) RDLNKTBS (Radio link counter BS )=20,(Aircom Recommendation: 16 SACCH, )

Radio_link_timeout governs the number of missing downlink SACCH messages which should

occur before a radio-link-loss is determined by the mobile.

It is recommended to set this timeout to 7.7 seconds (16 SACCH) for all cells, in line with the

link_fail recommendation above.

It is a very small percentage of calls which would recover from a losing SACCH for longer

than 7.7 seconds and the user is likely to have released the call anyway due to loss of audio.

This will help to maximize the use of TCH resources by returning them to the radio resource

pool as soon as possible, but without losing calls which might otherwise recover..

If .Call Re-Establishment. (see parameter CREALL) is enabled a low value of radio link time-

out increases the number of call reestablishments because a decrease of RDLNKTO may lead

to an earlier declaration of radio link failures

object: PWRC

range: 4-64

step size: 4 (range 4, 8, 12, ... 60, 64)

default: 20

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4) RDLNKTO (Radio link timeout=4), (Aircom Recommendation:16 SACCH, )

The link fail timer governs the number of missing uplink SACCH messages that

should occur before a radio-link-loss is determined by the BSS.

As the loss of uplink SACCH indicates that uplink audio is also lost, it is likely that

the subscriber will have terminated the call after 16 SACCH multiframes have

passed. This represents a time period of 7.7 seconds. The benefit of minimizing this timer value is that the holding time of the channel

following any radio link loss is minimized, while still allowing sufficient time for

the link to recover before the subscriber gives up and terminates the call.

object: BTS [BASICS]range: 0..150 = counter value 415 = counter value 64default: 4

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5) T3109 =HLFSEC-8 (TCH Reallocation Timer), This timer prevents the reallocation of a channel, following the detection of an

uplink radio link loss. The MS may still be transmitting on the channel until

radio_link_timeout expires.

T3109 should therefore be set to a value greater than radio_link_timeout.

Based on a radio_link_timeout of 16 SACCH as recommended above, then it isrecommended that T3109 should be reduced to 8000ms for all cells. This will ensure

that channels will be released as soon as is safely possible following a radio link

loss, increasing channel availability, avoiding any unnecessary SDCCH or TCH

congestion.

object: BTS [TIMER]

units: MS100 = 100 ms

HLFSEC = 0,5 sec

SEC5 = 5s

range: 0..255

default: HLFSEC-8

T3109

purpose: timer for forced deactivation of radio channels in case of

communication loss towards the MS

start: sending of the CHANNEL RELEASE message

expiry action: sending of the RF CHANNEL RELEASE message

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6) BSCT10=HLFSEC-10, (Assignment Guard Timer))=> 14000 (Aircom)),

This timer runs at the BTS during the assignment procedure, guarding the non-receipt of the

assignment complete or assignment failure message from the MS.

On expiry of this timer, the radio channels will be released and a Clear Request message sent

to the MSC .

This timer must be sufficiently long to maximize the probability of a successful assignment. In

worst case conditions the MS will take about 13s to fail an assignment and recover to thesource channel. Therefore the timer setting 14000 ms is recommended.

object: BSC [TIMER]unit: HLFSEC=0,5s

SEC5=5s

range: 0..254

default: HLFSEC-10

T10

purpose:

a)Assignment procedure: release of the associated resources if the MS is lost during the

assignment procedure.

b)Intra-cell handover: keep the old channels available for a sufficient time in order to

allow the MS to return to the old channel return to it if the handover is not successful andto release the old channel if the MS is lost during the handover procedure.

start: a) & b): sending of an ASSIGNMENT COMMAND by the BSC

stop: a) & b): receipt of an ASSIGNMENT COMPLETE or an ASSIGNMENT

FAILURE from the MS

expiry action: a)Assignment procedure: Sending of an ASSIGNMENT FAILURE to the

MSC with cause radio interface message failure followed by release of the call resources.

b)Intra-cell handover: Sending of a CLEAR REQUEST to the MSC with

cause radio interface message failure followed by release of the call

resources (CLEAR CMD received from MSC).

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7) BSCT8=HLFSEC-10, (Handover Guard Timer)=> 14000 (Aircom)),

This timer runs at the source BTS during an intra-BSC or inter-BSC handover.

This timer determines the time to receive the HANDOVER COMPLETE message.

T8 is defined as the time that BSC layer 3 will wait for a handover to complete before

releasing the source channel.

The value must be bigger than the sum of the time for all messages to be sent to the MS plus

the time to access a target and come back (if necessary). Rule: BSCT8 < TTRAU (for TTRAU see command SET BTS [TIMER])

This setting is necessary to ensure that a signaling failure (T8 and T10) is detected before

transcoder failure (TTRAU)

object: BSC [TIMER]unit: HLFSEC=0,5s

SEC5=5s

range: 0..254

default: HLFSEC-10

T8

purpose: keep the old channels available for a sufficient time in order to allow the MS to

return to the old channel return to it if the handover is not successful and to release the

old channel if the MS is lost.start: transmission of a HANDOVER COMMAND from the BSC to the MS

stop:

a) intra-BSC handover: receipt of a HANDOVER COMPLETE or a HANDOVER

FAILURE from the MS

b) inter-BSC handover: receipt of a CLEAR COMMAND from the MSC

or HANDOVER FAILURE from the MS

expiry action:Sending of a CLEAR REQUEST to the MSC with cause radio interface

message failure followed by release of the call resources (CLEAR CMD received fromMSC).

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T3101=HLFSEC-6, This timer is started, when a channel

is allocated with an IMMEDIATE ASSIGNMENT

message and stopped when the MS has correctly seized

the channels (ESTABLISH INDICATION is received for

the assigned channel). If the dedicated channel is not

established before T3101 expires, the allocated channel is

released.

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T3105=MS10-10, The Timer T3105 is used for the

repetition of PHYSICAL INFORMATION message

during the handover procedure between non synchronized

cells. After receipt of HANDOVER ACCESS bursts with

a correct handover reference the BSS sends a PHYSICAL

INFORMATION message to the MS and starts timerT3105.

BSS


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2BSS Parameter for Priority Layer

Serving Cell

PL = Priority Layer Serving CellValue Range: 0 ... 15 step 1

Neighbour Cell - MSSHO deactivated (MSSHO = Mobile Speed Sensitive HO)

PLNC(n)= Priority LayerNeighbourCellValue Range: 0 ... 15 step 1

Neighbour Cell - MSSHO activated

Handover DelayTimer not yet started or still runningPPLNC(n)= Penalty Priority LayerNeighbourCell

Value Range: 0 ... 15 step 1

Handover Delay Timer is expired

PLNC(n)= Priority LayerNeighbourCell

Value Range: 0 ... 15 step

Handover


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Handover

1800 900 HO

Better Cell HO: is not permitted, PLNC (900) > PL (1800)

Level HO: Calls will be HO from 1800 layer to 900 layer if you reach a certain levelset by the HOLTHLVDL parameters

Main Parameters :

HOLTHLVDL (0-63): Lower threshold for rxlevel on the downlink for handover (e.g.25)

RXLEVMIN (0-63): minimum received signal strength in 900 cell for HO (e.g. 10)

PLNC (0-15): priority layer of the neighbor cell (e.g. 9)

PL = 9

PL= 6

900

1800

900

1800

PLNC =9

Cell A

Cell B

Cell C

Cell D

Distance

Signal

Level

HOLTHLDL

Cell A

Cell C

Handover


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Handover

1800 1800 HO

Better Cell HO:permitted as the Priority of the 1800 cells are the same.

Level HO:permitted

Main Parameters :

HOM (0-126) (63= 0dB): Handover Margin for Better cell HO (e.g 68)


HIERF (0-1): is used to switch between two ranking methods for Level HO (e.g. 0)

PLNC: e.g. 6

PL = 9

PL= 6

900

1800

900

1800

PLNC =6

Distance

Signal

Level

HOM

Cell A Cell B

Cell A

Cell B

Cell CCell D

Handover


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Handover

900 1800 HO

Better Cell HO:permitted as the Priority of the 1800 cells are higher than the 900 cells.

Level HO:permitted, but not likely to happen

Main Parameters :

HOM (0-126) (63= 0dB): Handover Margin for Better cell HO, -ve HO (e.g. 53)


PLNC: e.g. 6

PL = 9

PL= 6

900

1800

900

1800

PLNC =6

Distance

Signal

Level

RXLEVMIN

Cell B

Cell D

Cell ACell B

Cell CCell D

Handover


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Handover

900 900 HO

Better Cell HO:permitted as the Priority of the 900 cells are the same.

Level HO:permitted

Main Parameters :

HOM (0-126) (63= 0dB): Handover Margin for Better cell HO (e.g. 68)


PLNC: e.g. 9

PL = 9

PL= 6

900

1800

900

1800

PLNC =9

Distance

Signal

Level

HOM

Cell C Cell D

Cell ACell B

Cell CCell D

Forced Handover (Directed Retry)


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Forced Handover (Directed Retry)

It occurs when no resources is available in the cell camped on

Main Parameters :

FHORLMO (0-24): offset for forced HO is a cell specific parameter used withintheBTS to select only target cells for forced HO which the MS can HO too.(e.g. 0 for900 cells, 6 for1800 cells)

TIMERFHO (1-320) (1 step = 10sec) :Timer to control the back Handover to sourcecell in case of forced HO (e.g. 10)

PL = 9

PL= 6

900

1800

900

1800

Cell A

Cell B

Cell CCell D

Mobile Speed Sensitive Handover


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HCS is capable of taking into account the mobile speed

The Mobile Speed Sensitive HO functionality shifts stationary and slow-moving

traffic to indoor (pico) or micro cell layers

Better call quality

reduced congestion in the macro cell layers

The Mobile Speed Sensitive HO functionality steers and keeps fast-moving traffic to

macro or umbrella cell layers

enhanced grade of service

reduced signaling load in the fixed network


Example


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Example

Macrocell

Slow Mobile SMat (3,6km/h)

start of timerandmicro-coverage

end ofmicro-coverage

delay timer not startedFast Mobile FMat (36km/h)

200m0

0

delay time: 20 sec

Microcell

m

snap shot at t=10 sec;delay timer is running

0

0}m

MSSHO

200m

snap shot at t=22 sec;delay timer expired

0

0

}m


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Siemens Parameters Training

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