-
Section 4 Module 8 Page 1
All Rights Reserved 2007, Alcatel-Lucent3JK10665AAAAWBZZA
Edition 1
Do not delete this graphic elements in here:
All Rights Reserved Alcatel-Lucent 2007Alcatel-Lucent W-CDMA
UMTS Radio Principles
Module 8HSDPA Scenarios
3JK10665AAAAWBZZA Edition 1
Section 4HSDPA Description
-
Section 4 Module 8 Page 2
All Rights Reserved 2007, Alcatel-Lucent3JK10665AAAAWBZZA
Edition 1
All Rights Reserved Alcatel-Lucent 2007Alcatel-Lucent W-CDMAUMTS
Radio Principles
HSDPA Description HSDPA Scenarios 4 8 2
Blank Page
This page is left blank intentionally
First editionLast name, first nameYYYY-MM-DD01
RemarksAuthorDateEdition
Document History
-
Section 4 Module 8 Page 3
All Rights Reserved 2007, Alcatel-Lucent3JK10665AAAAWBZZA
Edition 1
All Rights Reserved Alcatel-Lucent 2007Alcatel-Lucent W-CDMAUMTS
Radio Principles
HSDPA Description HSDPA Scenarios 4 8 3
Objectives
After this section, you will be able toz Describe main
procedures associated with
HSDPA call establishment and mobility.
-
Section 4 Module 8 Page 4
All Rights Reserved 2007, Alcatel-Lucent3JK10665AAAAWBZZA
Edition 1
All Rights Reserved Alcatel-Lucent 2007Alcatel-Lucent W-CDMAUMTS
Radio Principles
HSDPA Description HSDPA Scenarios 4 8 4
Objectives [cont.]
This page is left blank intentionally
-
Section 4 Module 8 Page 5
All Rights Reserved 2007, Alcatel-Lucent3JK10665AAAAWBZZA
Edition 1
All Rights Reserved Alcatel-Lucent 2007Alcatel-Lucent W-CDMAUMTS
Radio Principles
HSDPA Description HSDPA Scenarios 4 8 5
Table of Contents
Switch to notes view! Page
1 Call Setup 71.1 Call Establishment 8
Channel Type Selection 91.2 Initial Connection Establishment
101.3 RAB Assignment Phase 11
2 Mobility 122.1 Intra-Frequency Mobility 13
HS-DSCH Primary Cell Change 142.3 Inter-frequency HSDPA HHO with
Measurements 15
3 Iub Flow Control 163.1 Flow Control Principles 173.2 HS-DSCH
Capacity Allocation 18
Summary 19Self-Assessment on the Objectives 20End of Module
21
-
Section 4 Module 8 Page 6
All Rights Reserved 2007, Alcatel-Lucent3JK10665AAAAWBZZA
Edition 1
All Rights Reserved Alcatel-Lucent 2007Alcatel-Lucent W-CDMAUMTS
Radio Principles
HSDPA Description HSDPA Scenarios 4 8 6
Table of Contents [cont.]
Switch to notes view!
This page is left blank intentionally
-
Section 4 Module 8 Page 7
All Rights Reserved 2007, Alcatel-Lucent3JK10665AAAAWBZZA
Edition 1
All Rights Reserved Alcatel-Lucent 2007Alcatel-Lucent W-CDMAUMTS
Radio Principles
HSDPA Description HSDPA Scenarios 4 8 7
1 Call Setup
-
Section 4 Module 8 Page 8
All Rights Reserved 2007, Alcatel-Lucent3JK10665AAAAWBZZA
Edition 1
All Rights Reserved Alcatel-Lucent 2007Alcatel-Lucent W-CDMAUMTS
Radio Principles
HSDPA Description HSDPA Scenarios 4 8 8
1 Call Setup
1.1 Call Establishment
How is HSDPA triggered by the network?
CoreNetwork
1. Request for service(e.g. Web Browsing)
UE
Node B
RNC
2. RAB AssignmentRequest4. HS-DSCH
Establishment
3. DCH ? HS-DSCH ?Channel Type Selection
-
Section 4 Module 8 Page 9
All Rights Reserved 2007, Alcatel-Lucent3JK10665AAAAWBZZA
Edition 1
All Rights Reserved Alcatel-Lucent 2007Alcatel-Lucent W-CDMAUMTS
Radio Principles
HSDPA Description HSDPA Scenarios 4 8 9
1.1 Call Establishment
Channel Type Selection
RAB assignment request from CN
HS-DSCH or DCH ?
HS-DSCHselection
RAB Traffic Class
Traffic Class =
Interactive/Background
UE Capabilities
Cell Capability
HSDPA UE?
Primary Cell = HSDPA Cell?
Service = PS?
With the introduction of HSDPA in the UTRAN, a new type of
transport channel can be allocated to serve the RAB requested from
the CN. Thus, the channel type selection algorithm allows selecting
either DCH or HS-DSCH depending on the RAB characteristics received
from the CN.
At reception of a RAB assignment Request, the SRNC selects the
transport channel type between DCH and HS-DSCH according to the
following constraints:
z RAB traffic class} Only PS RABs with traffic class interactive
and background are transported on HS-DSCH
z UE capability to support HS-DSCH} HS-DSCH can be selected only
if UE supports it, as indicated by the UE capability Support of
HS-PDSCH,
and if UE supports the combination of already established DL DCH
and HS-DSCH, as indicated by the UE capability DL capabilities with
simultaneous HS-DSCH configuration
z Cell capability to support HS-DSCH} HS-DSCH can be selected
only if one cell of the active set supports HSDPA or if one
collocated cell (on
another carrier) supports HSDPA.
Channel type selection is performed prior to radio admission
control. Then depending on the channel type selection, either DCH
RAC or HSDPA RAC is triggered.
-
Section 4 Module 8 Page 10
All Rights Reserved 2007, Alcatel-Lucent3JK10665AAAAWBZZA
Edition 1
All Rights Reserved Alcatel-Lucent 2007Alcatel-Lucent W-CDMAUMTS
Radio Principles
HSDPA Description HSDPA Scenarios 4 8 10NodeBUE RNC SGSN
1 Call Setup
1.2 Initial Connection Establishment
RRC / RACH / RRC Connection Request
Establishment CauseAS Indicator
NBAP / RL Setup Request
NBAP / RL Setup Response
RRC / RACH / RRC Connection Setup Complete
RRC / FACH / RRC Connection Setup
SRB Definition (DCCH)U-RNTITarget RRC State (Cell_DCH)
HSDPA CapabilityUE Category
RRC / DCCH / Initial Direct Transfer (Service Request)
RANAP / Service Request
RRC / DCCH / Measurement Control
Most of the steps of this first phase are common to all type of
calls. There are few elements specific to HSDPA.
RRC Connection Request embeds the Establishment Cause and the AS
Indicator that may be used for Traffic Segmentation.
RRC Connection Setup states the properties of the SRB to be used
and includes a first Adio NEtwork Temporary Identifyer.
RRC connection Setup Complete indicates to RNC UE
capabilities.
-
Section 4 Module 8 Page 11
All Rights Reserved 2007, Alcatel-Lucent3JK10665AAAAWBZZA
Edition 1
All Rights Reserved Alcatel-Lucent 2007Alcatel-Lucent W-CDMAUMTS
Radio Principles
HSDPA Description HSDPA Scenarios 4 8 11
1 Call Setup
1.3 RAB Assignment PhaseNodeBUE RNC SGSN
NBAP / RL Reconfiguration Prepare
NBAP / RL Reconfiguration Ready
Measurement Power OffsetScheduler & HARQ propertiesMAC-d PDU
sizeHS-DPCCH properties
RRC / DCCH / Radio Bearer Setup
RANAP / RAB Assignment Request
RRC / DCCH / Radio Bearer Setup Complete
HS-SCCH CodesNumber of HARQ
NBAP / RL Reconfiguration Commit
RANAP / RAB Assignment Response
HS-SCCH CodesHARQ number and propertiesH-RNTIMeasurement Power
OffsetHS-DPCCH properties
In this second phase only the NBAP Radio Link Reconfiguration
procedure and RRC Radio Bearer Reconfiguration are modified because
of HSDPA.
-
Section 4 Module 8 Page 12
All Rights Reserved 2007, Alcatel-Lucent3JK10665AAAAWBZZA
Edition 1
All Rights Reserved Alcatel-Lucent 2007Alcatel-Lucent W-CDMAUMTS
Radio Principles
HSDPA Description HSDPA Scenarios 4 8 12
2 Mobility
-
Section 4 Module 8 Page 13
All Rights Reserved 2007, Alcatel-Lucent3JK10665AAAAWBZZA
Edition 1
All Rights Reserved Alcatel-Lucent 2007Alcatel-Lucent W-CDMAUMTS
Radio Principles
HSDPA Description HSDPA Scenarios 4 8 13
2 Mobility
2.1 Intra-Frequency Mobility
R4 cell HSDPA cell HSDPA cell HSDPA cell
DCHFallback
HS-DSCHTransition
HS-DSCHMobility
Core Network
RNC
HS-DSCHMobility
RNC
NodeB NodeB
Primary Cell
DCH only
HS-DSCH+DCH
HS-DSCHMobility
HS-DSCHMobility
Primary cell change
As defined by 3GPP HS-DSCH is established in only one cell so is
never in soft handover. In Alcatel-Lucent implementation HS-DSCH is
established in the primary cell because it is the best candidate
(good radio conditions and not changing too often).
Each time the primary cell changes the HS-DSCH RL is deleted on
the former primary right after the RRC Measurement Control
procedure has been performed, and it is re-established under the
new primary, using a synchronous reconfiguration.
If the new primary cell does not support HSDPA then the RB is
reconfigured to DCH (iRM CAC is performed). If the new primary cell
supports HSDPA while the former did not, and given that the UE
supports HSDPA, then the RB is reconfigured to HS-DSCH (HSDPA CAC
is performed).
-
Section 4 Module 8 Page 14
All Rights Reserved 2007, Alcatel-Lucent3JK10665AAAAWBZZA
Edition 1
All Rights Reserved Alcatel-Lucent 2007Alcatel-Lucent W-CDMAUMTS
Radio Principles
HSDPA Description HSDPA Scenarios 4 8 14
Activation CFN
2.1 Intra-Frequency Mobility
HS-DSCH Primary Cell Change
RNC source Node B
target Node B
UE
RB Reconfiguration (Activation CFN)
RL Reconfiguration Ready
Measurement Control (new neighbouring list)
RL Reconfiguration Prepare
RB Reconfiguration Complete
Primary cell change
RL Reconfiguration Ready
RL Reconfiguration Prepare
RL Reconfiguration Commit (Activation CFN)
RL Reconfiguration Commit (Activation CFN)
As defined by 3GPP HS-DSCH is established in only one cell so is
never in soft handover. In Alcatel-Lucent implementation HS-DSCH is
established in the primary cell because it is the best candidate
(good radio conditions and not changing too often).
Each time the primary cell changes, the HS-DSCH RL is deleted on
the former primary and it is reestablishedunder the new primary,
using a synchronous reconfiguration. During the reconfiguration
data transfer on HS-DSCH is suspended by the RNC.
If it is not possible to re-establish HS-DSCH on the new primary
(CAC failure) then the radio bearer may fall back to DCH.
If the new primary cell does not support HSDPA then the RB is
reconfigured to DCH (iRM CAC is performed). In case of CAC failure
for the DCH then the PS RAB is released.
If the new primary cell supports HSDPA while the former did not
and given the UE supports HSDPA, then the RB is reconfigured to
HS-DSCH. In case of CAC failure the radio bearer stays on DCH.
In the case the current primary cell is not present in the new
active set, the HS-DSCH link is deleted right after the Active Set
procedure (and before the Measurement Control procedure) and the UE
releases the HSDPA link. A new HS-DSCH link is then setup using a
normal SRLR procedure on the new primary cell after the Measurement
Control.
-
Section 4 Module 8 Page 15
All Rights Reserved 2007, Alcatel-Lucent3JK10665AAAAWBZZA
Edition 1
All Rights Reserved Alcatel-Lucent 2007Alcatel-Lucent W-CDMAUMTS
Radio Principles
HSDPA Description HSDPA Scenarios 4 8 15
2 Mobility
2.3 Inter-frequency HSDPA HHO with Measurements
R99 cellFrequency 1
HSDPA cell Frequency 2
Core Network
SRNC
The HSDPA Inter-freq mobility (HHO) with measurements (i.e.
Compressed Mode on associated DCH) is
supported with UA05.
The feature values are to Enable HSDPA call handover to another
cell based on criteria thresholds, avoiding
drop calls and to allow HSDPA mobiles entering an HSDPA cell
through an alarm handover to benefit from
HSDPA service.
UE solution supporting the Compressed Mode on DCH once in HSDPA
operation (i.e. HS-PDSCH(s) usage).
-
Section 4 Module 8 Page 16
All Rights Reserved 2007, Alcatel-Lucent3JK10665AAAAWBZZA
Edition 1
All Rights Reserved Alcatel-Lucent 2007Alcatel-Lucent W-CDMAUMTS
Radio Principles
HSDPA Description HSDPA Scenarios 4 8 16
3 Iub Flow Control
-
Section 4 Module 8 Page 17
All Rights Reserved 2007, Alcatel-Lucent3JK10665AAAAWBZZA
Edition 1
All Rights Reserved Alcatel-Lucent 2007Alcatel-Lucent W-CDMAUMTS
Radio Principles
HSDPA Description HSDPA Scenarios 4 8 17
3 Iub Flow Control
3.1 Flow Control Principles
IubCapacity Request
Control FPCapacity Allocation
Control FPData FP
RNC
RNC Buffers
NodeB Buffers
QId0 QId1 QIdNQId2 QId0 QId1 QIdNQId2
With HSDPA, the effective throughput per UE is not deterministic
and quite variable. A flow control mechanism has been introduced
between the RNC Mac-d and the NodeB MAC-hs entities in order to
fill the NodeB buffers with sufficient data to provide to the UEs
and be quite reactive to throughput variations.
This flow control mechanism is based on three main
procedures:
z the Capacity Request procedure that provides means for the RNC
to indicate for each session of each UE its buffer occupancy (at
MAC-d level).
z the Capacity Allocation procedure generated by the NodeB to
indicate to the RNC how many PDUs are required for the desired
session and the interval in which data should be sent. This is
based on the estimated throughput for this session and the amount
of unsent data in NodeB transmission buffers.
z the HS-DSCH data transfer procedure in which the RNC sends the
MAC-d PDUs grouped in FP frames (1 to 255 PDUs per FP frame). The
updated buffer occupancy is also given. The RNC may choose to send
all the required MAC-d PDUs in a single FP frame, or to space out
(within the notified interval) the transmission in several FPs.
-
Section 4 Module 8 Page 18
All Rights Reserved 2007, Alcatel-Lucent3JK10665AAAAWBZZA
Edition 1
All Rights Reserved Alcatel-Lucent 2007Alcatel-Lucent W-CDMAUMTS
Radio Principles
HSDPA Description HSDPA Scenarios 4 8 18
3.1 Flow Control Principles
3.2 HS-DSCH Capacity Allocation
ServingRNC
NB.: The UE is in cell_DCH state
UE Node B
HS-DSCH FP
MAC-hsMAC-hs
HS-DSCH FP
HS-DSCH FPHS-DSCH FP
9. Data Transfer
11. Data Transfer
10. HS-SCCH
Priority Indicator, UE buffer Size
8. HS-DSCH Capacity Allocation
HS-DSCH credits, inter-TTI interval,
7. HS-DSCH Capacity Request
After HS-DSCH Configuration
As soon as the SRNC detects the necessity to send HS-DL data on
one HS-DSCH, it sends an HS-DSCH Capacity Request control frame
within the HS-DSCH Frame Protocol to the CRNC. Parameters: Common
Transport Channel Priority Indicator and User Buffer Size. The CRNC
forwards this message (HS-DSCH Capacity Request control frame) to
the Node B. So in this example sequence, the CRNC does not
interfere with the HS-DSCH scheduling.Parameters: Common Transport
Channel Priority Indicator and User Buffer Size.
The Node B determines the amount of data (credits) that can be
transmitted on the HS-DSCH and reports this information back to the
DRNC in a HS-DSCH Capacity Allocation control frame in the HS-DSCH
Frame Protocol.Parameters: Common Transport Channel Priority
Indicator, HS-DSCH Credits, HS-DSCH Interval, HS-DSCH Repetition
period, Maximum MAC-d PDU length.The DRNC sends the HS-DSCH
Capacity Allocation control frame to SRNC. So again, the DRNC does
not react itself to that message in this example.Parameters: Common
Transport Channel Priority Indicator, HS-DSCH Credits, HS-DSCH
Interval, HS-DSCH Repetition period, Maximum MAC-d PDU length.
The SRNC starts sending DL data to the Node B. This is done via
the two HS-DSCH Frame Protocol "hops" on Iurand Iub interface. The
Node B schedules the DL transmission of DL data on HS-DSCH which
includes allocation of PDSCH resources.
The Node B transmits the control information for the concerned
UE using the HS-SCCH.
The Node B sends the HS-DSCH data to the UE on the
HS-PDSCH(s).
-
Section 4 Module 8 Page 19
All Rights Reserved 2007, Alcatel-Lucent3JK10665AAAAWBZZA
Edition 1
All Rights Reserved Alcatel-Lucent 2007Alcatel-Lucent W-CDMAUMTS
Radio Principles
HSDPA Description HSDPA Scenarios 4 8 19
Summary
-
Section 4 Module 8 Page 20
All Rights Reserved 2007, Alcatel-Lucent3JK10665AAAAWBZZA
Edition 1
All Rights Reserved Alcatel-Lucent 2007Alcatel-Lucent W-CDMAUMTS
Radio Principles
HSDPA Description HSDPA Scenarios 4 8 20
Self-Assessment on the Objectives
z Please be reminded to fill in the formSelf-Assessment on the
Objectivesfor this module
z The form can be found in the first partof this course
documentation
-
Section 4 Module 8 Page 21
All Rights Reserved 2007, Alcatel-Lucent3JK10665AAAAWBZZA
Edition 1
All Rights Reserved Alcatel-Lucent 2007Alcatel-Lucent W-CDMAUMTS
Radio Principles
HSDPA Description HSDPA Scenarios 4 8 21
End of ModuleHSDPA Scenarios