HSDPA RRM

1 © Nokia Siemens Networks RN31679EN30GLA1

HSDPA RRM & parameters


HSDPA Principles

High Speed Downlink Packet Access (HSDPA) based on:• Node B decisions • Multi-code operation• Fast Link Adaptation

• Adaptive Modulation & Coding AMC• Fast Packet Scheduling• Fast H-ARQ• Fast 2 ms TTI*• Downwards Compatibility with R99

• (shared or dedicated carrier)

* TTI = 1 Subframe = 3 Slots = 2 msH-ARQ: Hybrid Automatic Repeat Request

Motivation:- enhanced spectrum efficiency- higher peak rates >> 2 Mbps- higher cell throughput- reduced delay for ACK transmission

3GPP Rel. 5; TS 25.308:

“HSDPA Overall Description”

3GPP Rel. 5; TS 25.308:

“HSDPA Overall Description”

•••up to 15 HS – Physical

DL Shared Channels

HSDPAenabledWCEL; 0 = disabled; 1 =

enabled


Principles of DC HSDPA

SSHSC

S1: TBS B

S1: TBS A

Primary serving cell

HS-SCCHHS-PDSCHF-DPCH (RAN1201)

E-DPDCHE-DPCCHHS-DPCCHDPCCH

HS-SCCHHS-PDSCH

• Dual-Cell HSDPA of 3GPP Rel8 uses two adjacent WCDMA carriers (same bandwidth) to transmit data for a single UE

• Can be used with MIMO 2x2 and/or 64QAM• DC HSDPA UEs are assigned HS-PDSCHs in the primary serving cell & Secondary Serving High Speed

Cell (SSHSC)• UL (CQI, ACK/NACK) for DC HSDPA UEs via primary serving cell (no UL in SSHSC)• Besides HS-DSCH the primary serving cell is carrying

– The full set of control & common control channels

– UL transport channels E-DCH HS-DPDCH + optional DC HS-DPCCH (HSUPA UEs)

• SSHSC is left clean from control signaling (max. HS-DSCH capacity)– Among common channels only CPICH is used in SSHSC

– E-AGCH, E-RGCH, E-HICH in SSHSC existent but not used by DC HSDPA

f1

f2

DCellHSDPAEnabledWCEL; 0 = disabled; 1 =

enabled


Adaptive Modulation & Coding (1/2)

I

Q0000

0010

0011

0001

1000

1010

1011

1001

1100

1110

1111

1101

0100

0110

0111

0101

16QAM

4-Bit KeyingQPSK

2-Bit Keying

Q

I

(1,1)(0,1)

(1,0)(0,0)

HSDPA uses• QPSK• 16QAM• 64QAM*dynamically based on quality of the radio link

* defined in 3GPP Rel. 7 / implemented with NSN RU20


Adaptive Modulation & Coding (2/2)

RateMatching

Puncturing /Repetition

RateMatching

Puncturing /Repetition

Turbo Coding1/3

Turbo Coding1/3

EffectiveCode Rate:

1/4 - 3/4

HSDPA Adaptive Coding• based on the R’99 1/3 Turbo Coding• Rate Matching: Puncturing or Repetition code rate: 1/6 – 4/4

• dynamically based on quality of the radio link

HSDPA Adaptive Coding• based on the R’99 1/3 Turbo Coding• Rate Matching: Puncturing or Repetition code rate: 1/6 – 4/4

• dynamically based on quality of the radio link


TURBO CODING

1) ¼ qpsk2) 2/4 QPSK3) ¾ QPSK4) 2/4 16QAM5) ¾ 16QAM6) 4/4 16QAM- 14.4Mbps7) ¾ 64QAM8) 5/6 64QAM9) 4/4 64QAM --- 21.6Mbps


C1,0 = [1]

C2,1 = [1-1]

C2,0 = [11]

C4,0 = [1111]

C4,1 = [11-1-1]

C4,2 = [1-11-1]

C4,3 = [1-1-11]

C8,0 = [11111111]

C8,1 = [1111-1-1-1-1]

C8,2 = [11-1-111-1-1]

C8,3 = [11-1-1-1-111]

C8,4 = [1-11-11-11-1]

C8,5 = [1-11-1-11-11]

C8,6 = [1-1-111-1-11]

C8,7 = [1-1-11-111-1]

C16,0 = [.........]C16,1 = [.........]

C16,15 = [........]

C16,14 = [........]

C16,13 = [........]

C16,12 = [........]

C16,11 = [........]

C16,10 = [........]

C16,9 = [.........]

C16,8 = [.........]

C16,7= [.........]

C16,6 = [.........]

C16,5 = [.........]

C16,4 = [.........]

C16,3 = [.........]

C16,2 = [.........]

SF = 1

2 4 8 SF = 16

256 512...

SF = 16 240 ksymb/s

Multi-Code operation:

1..15 codes 0.24 .. 3.6 Msymb/s

SF = 16 240 ksymb/s

Multi-Code operation:

1..15 codes 0.24 .. 3.6 Msymb/s

Multi Code Operation (1/3)


Multi Code Operation (2/3)

RU20 includes3GPP Rel. 7 features:• 64QAM (RAN1643)

ModulationModulation

QPSKQPSK

Coding rateCoding rate

1/41/4

2/42/4

3/43/4

5 codes5 codes 10 codes10 codes 15 codes15 codes

600 kbps600 kbps 1.2 Mbps1.2 Mbps 1.8 Mbps1.8 Mbps

1.2 Mbps1.2 Mbps 2.4 Mbps2.4 Mbps 3.6 Mbps3.6 Mbps


16QAM16QAM

2/42/4

3/43/4

4/44/4




64QAM64QAM

3/43/4

5/65/6

4/44/4




64QAM 6 bits/symbol

HSDPA64QAMAllowedWCEL; 0 (Disabled), 1 (Enabled)


UEIub

Uu

Re

du

ce

dre

tran

sm

iss

ion

Re

du

ce

dre

tran

sm

iss

ion

RNC:functionalities

shifted toNode B

RNC:functionalities

shifted toNode B

„more intelligence“new functionalities

new UEs HSDPA Capability

Classes

new UEs HSDPA Capability

Classes

Network Modifications for HSDPA

UTRAN & UE:• modified PHY layer• modified MAC

• modified transport and physical channels• modified coding• modified modulation

new Node B functionalities:• Acknowledged transmission: Fast H-ARQ faster retransmission / reduced delays ! less Iub retransmission traffic ! higher spectrum efficiency !

• Fast Packet Scheduling fast & efficient resource allocation !

• Fast Link Adaptation Adaptive Modulation & Coding ! compensation of fast fading (without fast PC) higher peak rates & spectrum efficiency !

Node B


TNL

MAC-d

DCHFP

DCHFP

MAC-d

TNL

Node B Iub RNC

RLC RLC

PHY PHY TNL

MAC-d

MAC-hsMAC-ehs

HS-DSCH FP

MAC-d

TNL

UE Uu Node B Iub RNC

RLC RLCMAC-d flow

HS-DSCH

PHY PHY

UE Uu

DCH

DPCH

HS-PDSCH

R99

HSDPA(R5)

(e)hs: (enhanced) high speedTNL : Transport Network Layer

HSDPA Protocol Model

MAC-hsMAC-ehs

HS-DSCH FP

HSDPA(R7)


MAC-hs• supports HSDPA with 3GPP Rel. 5 • Tasks of MAC-hs within the Node B

• Flow control • Packet scheduling• H-ARQ • Transport format selection

• Tasks of MAC-hs within the UE• HARQ (see section layer 1 re-transmission)• Disassembly of transport blocks• Re-ordering

• Header & payload • Payload: Concatenating of one or more MAC-d PDU into single MAC-hs PDU• Header: 21 bits assuming single MAC-d PDU size

MAC-ehs• supports enhanced HS-DSCH functions of 3GPP Rel. 7 - 9• must be configured to support features such as: 64QAM (RAN1643), MIMO (RAN 1642), flexible RLC (RAN1638),

Dual-Cell HSDPA (RAN1906)

MAC-hs & MAC-ehs


Physical Channel Overview : Transport Channel HS share channel

HS-PDSCHHigh-Speed Physical DL Shared Channel


HS-SCCHHigh Speed Shared Control Channel

HS-SCCHHigh Speed Shared Control Channel

associated DCHDedicated Channel (Rel. 99)

associated DCHDedicated Channel (Rel. 99)

HS-DPCCHHigh Speed Dedicated Physical Control Channel

HS-DPCCHHigh Speed Dedicated Physical Control Channel

Node B

MAC-hs

F-DPCHFractional Dedicated Physical Channel (Rel. 6/7)

F-DPCHFractional Dedicated Physical Channel (Rel. 6/7)


HS-PDSCH (DL)• HS-PDSCH: High-Speed Physical Downlink Shared Channel

• Transfer of actual HSDPA data• 5 - 15 code channels• QPSK or 16QAM modulation• Divided into 2 ms TTIs• Fixed SF16

••• up to 15 HS – PDSCHs

HSPDSCHCodeSet HS-PDSCH code set; WCEL; (-) (-) (5 codes)

• HS-PDSCH code set parameter• Specifies whether number of

codes channels reserved for HSDPA is fixed* or dynamically

adjustable

• Minimum 5 code channels / Maximum 15 codes channels

• Possible numbers of code channels enabled / disabled bit wise


HS-SCCH (1/2)(DL)• HS-SCCH: High-Speed Shared Control Channel

• L1 Control Data for UE; informs the UE how to decode the next HS-PDSCH frame e.g. UE Identity, Channelization Code Set, Modulation Scheme, TBS, H-ARQ process

information• Fixed SF128• transmitted 2 slots in advance to HS-PDSCHs• NSN implementation with slow power control: shares DL power with the HS-PDSCH• more than 1 HS-SCCH required when code multiplexing is used

TBS: Transport Block Size

• Code multiplexing• HSDPA service for several users

simultaneously• For each user individual HS-

SCCH required• available only, if > 5 codes can

be reserved for HS-PDSCH

SF16HS-PDSCH

Time

User 1 User 2 User 3 User 4

Subframe2 ms

5

10

15

MaxNbrOfHSSCCHCodesMaximum number of HS-SCCH codes WCEL; RU10 & earlier: 1..3; 1; 1; RU20: 1..4


HS-SCCH (2/2)

128 128128

Available CCAllocated CC Blocked CC

SF16

SF32 32

SF64 64 64 64

SF256 256 256 256 256 256 256 256 256 256 256256 256256 256 256

128 128 128 128 128 128 128SF128

+15 x SF16

HS-PDSCH

CPICH

S-CCPCH1

S-CCPCH2 HS-SCCH HS-SCCH HS-SCCH

FACH-s: for Service Area Broadcast (CTCH)

P-CCPCHAICH

PICH


HS-DPCCH UL

• UL HS-DPCCH: High-Speed Dedicated Physical Control Channel• MAC-hs Ack/Nack information (send when data received)• Channel Quality Information (CQI reports send every 4ms, hardcoded period)• Fixed SF 256

HARQ-ACK(10 bit)

1 Slot = 2560 chip 2 Slots = 5120 chip

Subframe # 0 Subframe # i Subframe # N

1 HS-DPCCH Subframe = 2ms

CQI (20 bit)Channel Quality Indication

TS 25.21: CQI values = 0 (N/A), 1 .. 30; steps: 1;1 indicating lowest, 30 highest air interface quality

TS 25.21: CQI values = 0 (N/A), 1 .. 30; steps: 1;1 indicating lowest, 30 highest air interface quality


Associated DCH (DL & UL)

• DL DPCH: Associated Dedicated Physical Channel TPC• L3 signalling messages• Speech - AMR• Power control commands for associated UL DPCH

• UL DPCH: (DPDCH & DPCCH)• L3 signalling messages• Transfer of UL data 16 / 64 / 128 / 384 kbps, e.g. TCP

acknowledgements• Speech - AMR

DPDCH / DPCCH (time multiplexed)DPDCH: L3 signalling; AMR

DPCCH: TPC for UL DPCH power control

DPDCH: L3 signalling, AMR; TCP ACKs; 16 / 64 / 128 / 348 kbps

DPCCH: TPC, Pilot, TFCI


Fractional DPCH: F-DPCH (DL)

The Fractional DPCH (F-DPCH):• introduced in 3GPP Rel. 6 (enhanced in Rel. 7; NSN RU20 implementation based on

Rel. 7)• replaces the DL DPCCH• includes Transmit Power Control (TPC) bits but excludes TFCI & Pilot bits & SRB

– TFCI bits - no longer required as there is no DPDCH– Pilot bits - no longer required as TPC bits are used for SIR measurements– SRB mapped to E-DCH & HS-DSCH

• increases efficiency by allowing up to 10 UE to share the same DL SF256 channelization code

- time multiplexed one after another• RU20 feature RAN1201;

– requires Rel. 7 or newer UE– HSDPA & HSUPA must be enabled– Feature is licensed using an RNC ON/OFF license– License CPC exists and its state is ON

Tx OffTPC

Slot #i

1 time slot 2560 chips

Tx Off

256 chips

FDPCHEnabledWCEL; 0 (Disabled), 1 (Enabled)


SummaryCharacteristic RU10 RU20 RU30 RU40

HSDPA users per cell

≤ 64 ≤ 72 (RAN1668) ≤ 72 ≤ 128 (RAN2124)

Modulation QPSK/16QAMQPSK/16QAM & 64QAM (RAN1643)

QPSK/16QAM/64QAM QPSK/16QAM/64QAM

MIMO No Yes (2x2) (RAN1642) Yes Yes

Dual-Cell HSDPA No Yes (RAN1906) DC-HSDPADC-HSDPADB DC HSDPA (RAN2179)

Data rate per UE up to 14 Mbps up to 42 Mbpsup to 42 Mbps 84 Mbps (RAN 1907)

up to 84 Mbps (RAN1907)

Traffic ClassesInteractive + Background + Streaming

+ CS Voice over HSPA (RAN1689)

all traffic classesall traffic classes

Packet SchedulerProportional Fair (PF)+ QoS Aware HSPA Scheduling

PF + QoS aware scheduling

PF + QoS awarescheduling

PF + QoS awarescheduling

HSDPA Multi-RAB multiple RAB HSDPA + AMR

multiple RAB HSDPA + AMR

multiple RAB HSDPA + AMR, +CS64 Conv.

multiple RAB HSDPA + AMR, +CS64 Conv.

Code Multiplexing(Scheduled users per TTI)

Yes (up to 3) Yes (up to 4) Yes (up to 4) Yes (up to 4)

UL associated DCH 16, 64, 128, 384 Kbps 16, 64, 128, 384 Kbps 16, 64, 128, 384 Kbps 16, 64, 128, 384 Kbps

DB: Dual Band


•Most enhanced features must be licensed individually and are activated by setting individual off / on parameter

•Some features can be activated on cell level, others on WBTS or even RNC level only

Feature Activation

HSDPAenabledWCEL; 0 = disabled; 1 = enabled

HSDPA48UsersEnabledRNFC; 0 = disabled; 1 = enabled

HSDPA64UsersEnabledWCEL; 0 = disabled; 1 = enabled

HSDPA14MbpsPerUserWBTS; 0 = disabled; 1 = enabled

HSDPAMobilityServing HS-DSCH cell change & SHO on/off switchRNFC ; 0 = disabled; 1 = enabled

HspaMultiNrtRabSupportHSPA multi RAB NRT supportWCEL; 0 = disabled; 1 = enabled

HSDPADynamicResourceAllocationHSDPA Dynamic Resource AllocationRNFC; 0 = disabled; 1 = enabled

HSDPA16KPBSReturnChannelHSDPA 16 Kbps UL DCH return channel on/offRNFC; 0 = disabled; 1 = enabled

HSPA72UsersPerCellWCEL; 0 = disabled; 1 = enabledif enabled, max. 72 HSDPA/HSUPA users can be supported per cell.

HSPA128UsersPerCellWCEL; 0 = disabled; 1 = enabledif enabled, max. 128 HSDPA/HSUPA users can be supported per cell.

RU20/30

HSDPA64QAMAllowed; MIMOEnabled; DCellHSDPAEnabled; MIMOWith64QAMUsageWCEL; 0 (Disabled), 1 (Enabled)

DCellAndMIMOUsageWCEL; 0=DC-HSDPA and MIMO disabled; 1=DC-HSDPA and MIMO w/o 64QAM enabled; 2=DC-HSDPA and MIMO with 64QAM enabled

FDPCHEnabled; CPCEnabledWCEL; 0 (Disabled), 1 (Enabled)

HSPAQoSEnabledWCEL; 0..4; 1; 0 = disabled0 = QoS prioritization is not in use for HS transport1 = QoS prioritization is used for HS NRT channels2 = HSPA streaming is in use3 = HSPA CS voice is in use4 = HSPA streaming & CS voice are in use

RU40


HSDPA RRM


Link adaptation algorithm1) Generation of CQImeasured :

– UE monitors EC/I0

– UE reads PHS-PDSCH SIG (L3/RRC signalling)

2) UE reports CQImeasured every 4 ms (NSN solution) – can be increased with Mass Event Eandler

3) CQI Correction in Node BNode B corrects reported CQImeasured to CQIcompensated based on:

– actual HS-PDSCH power PHS-PDSCH TRUE

– Number of ACK & NACK

4) Link Adaptation decision: Node B decides about TB size for next sub-frame:– Modulation– Coding rate– Number of codes

CQI Reporting & Link Adaptation

••• up to 15 HS – PDSCHs

P-CPICH

HS – DPCCH (ACK; CQI)HS – SCCH

CQI used for:• Link Adaptation decision • Packet Scheduling decision

ACK/NACK used for:• H-ARQ process • Link Adaptation decision • HS-SCCH power adaptation

Remember:

* UE internal (proprietary) process

PHS-PDSCH: HS-PDSCH transmission power

TB: Transport Block

UE observesP-CPICH (Ec/Io)

CQImeasured*

CQImeasured*


CQI Compensation (1/3)CQImeasured

UE generates CQImeasured assuming Tx power PHS-PDSCH SIG = PCPICH + +

– calculated by RNC: = f x Min(PtxMaxHSDPA, PtxMax – PtxNonHSDPA) – PCPICH

PHS-PDSCH SIG = (f x Min(PtxMaxHSDPA, Ptxmax – PtxNonHSDPA)) [dBm] +

= Reference Power Adjustment (Power Offset) [dB] CQI tablesPtxMax = max. cell powerPtxNonHSDPA = total power allocated to R99 & DL control channels (latest report is taken)PtxMaxHSDPA = max. allowed HSDPA power

signalled to UE in case of HS-DSCH setup

Serving cell change

f = 0.7 for static HS-PDSCH power allocationf = 0.5 for dynamic HS-PDSCH power

CQI Compensation in Node B• Node B compensates CQI from differences between assumed HS-PDSCH

Tx power & actual HS-PDSCH Tx power PHS-PDSCH TRUE

– Part of HSDPA power used for HS-SCCH– HS-PDSCH power can vary because of dynamic power allocation

• Offset X used to convert reported CQImeasured into compensated CQIcompensatedCQIcompensated = CQImeasured + X [dB]

X = PHS-PDSCH TRUE – (PCPICH + + ) – A [dB]

correction A estimated by outer loop link adaptation algorithm


Outer loop link adaptation algorithm correction A• If ACK received for first transmission of a packet

– Correction A decreased by 0.005 dB– But not below -4 dB (maximum CQI improvement towards higher TBS)

• If NACK received for first transmission of a packet– Correction A increased by 0.05 dB– But not above 4 dB (maximum CQI downgrade towards lower TBS)

ACK for 1st transmission

NACK for 1st transmission

time

P0

CQI Compensation (2/3)

increase CQI

lower CQI


CQIMEASURED = 3233 bits per TB (167 K)e.g. PHS-PDSCH SIG = 37 dBm

e.g. PHS-PDSCH TRUE = 40 dBmX = (40 – 37) dB = 3 dBCQICOMPENSATED = 3 + 3 = 6461 bits per TB (230 K)

X = 3 dB

• CQI compensation makes it difficult to map reported CQI from UE log files into expected HSDPA transport block size TBS

CQI Compensation (3/3)


0

5

10

15

20

25

30

-15 -14 -13 -12 -11 -10 -9 -8 -7 -6 -5

CPICH Ec/Io (dB)

Com

pens

ated

Cha

nnel

Qua

lity

Indi

cato

r (C

QI)

PtxMaxHSDPA = 30 dBm



Compensated

Reported

CQI as a function of CPICH Ec/Io

Measurement Examples

• CQI improves both with increasing:

– EC/I0

– HSDPA power


• CQI estimation differs from one type of UE to the next one Prediction of different values in spite of identical channel conditions• CQI compensation capable to remove most of these differences Almost same service experienced in spite of proprietary CQI estimation

0

5

10

15

20

25

30

-15 -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3

CPICH Ec/Io (dB)

Cha

nnel

Qua

lity

Indi

cato

r (C

QI)

Samsung zx20

Novatel U740

Common Channel Loaded

Unloaded

0

5

10

15

20

25

30

-15 -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3

CPICH Ec/Io (dB)

Com

pens

ated

Cha

nnel

Qua

lity

Indi

cato

r (C

QI) Samsung zx20

Novatel U740

Common Channel Loaded

Unloaded

Prior to compensation After compensation

Measurement Examples


HSDPA RRM


R99 & HSDPA Retransmission

Terminal

BTS

R99 DCH R5 HS-DSCH

Packet

Re-transmission

RLC ACK/NACK

Re-transmission

L1 ACK/NACK

Packet

Terminal

BTS

RNC RNC

Dat

aflo

w

DL control moved to BTS

H-ARQ: Hybrid Automatic Repeat reQuest


Hybrid Automatic Repeat Request H-ARQ

• H-ARQ Objective:– ensures reliable data transfer between UE and Node B– short Round Trip Time between UE and network

• HSDPA connection re-transmission can originate from:– MAC-hs layer between UE and Node B (HARQ)– RLC layer between UE and RNC– TCP layer between UE and application server

• Re-transmission time out– after 3rd L1 re-transmission HSDPA packet discarded (hardcoded threshold)

• HARQ algorithms:– Chase combining CC– Incremental Redundancy IRAlgorithm selected by operator on BTS level

HARQRVConfigurationWBTS; 0 = Chase

Combining, 1 = Incremental

Redundancy


HSDPA RRM


Scheduler Types

• Supports packet schedulers– Round Robin RR

– Proportional Fair PF (requires individual license)

– Type of scheduler set by HSDPA.BB.Resource.Allocation commissioning parameter

Round Robin Scheduler• assigns sub-frames in rotation

– User at cell edge served as frequently as user at cell centre

• does not account for channel conditions experienced by UE– Low total throughput in cell

• if no data have to be transferred from Node B to certain UE then the sub-frame is assigned to the next one


Proportional Fair PF Scheduler (1/2)

TTI 1 TTI 2 TTI 3 TTI 4

USER 1 Es/N0USER 2 Es/N0

Scheduled user

• Takes into account multipath fading conditions experienced by UE

– Improved total throughput in cell in comparison to round robin

• Sub-frames assigned according scheduling metric

– Ratio instantaneous data rate / average data rate experienced in the past

– User at cell edge served less frequently as user at cell centre

Estimate of instantaneously supported user throughput

Based on compensated CQI

Calculated average user throughput in the past

Throughput measured every 10 ms with 100 ms sliding window

ave

inst

TP

TP


Round Robin RR scheduling

Max. total throughput 1100 KbpsProportional Fair PF scheduling

Max. total throughput 1300 Kbps

Example:

Macro cell≤ 5 codes for HSDPACarrier shared with R99Maximum total transmission power 20

WStatic HS-PDSCH + HS-SCCH power

Proportional Fair PF Scheduler (2/2)


Scheduling / HSDPA Code Multiplexing

UE1 UE2 UE3

Amount of

data in buffer

UE1 UE2 UE3

Full buffer Different data amounts

7

8

7

8

RU10 & later

15 codes2

10

5

8

3

10

Codes & power are divided optimally between users depending on data amount.

MaxNbrOfHSSCCHCodes

Max. number of HS-SCCH codesWCEL; 1..4*; 1; 1

(no Code Multiplexing)

HSDPA Code Multiplexing: enables simultaneous transmission of up to 4* HSDPA UEs during 1 TTI

– each simultan. served HSDPA UEs must have separate HS-SCCH– ≥ 5 codes must be allocated to HS-PDSCH– MAC-hs entity selects (3) best users (based on PF or QoS aware metric) for transmission in the next TTI– HS-PDSCH codes & power resources shared, taking into account:

how much data user has in its buffer Channel conditions of user

* 3 before RU20


Basics of QoS Aware Scheduling• Shortcomings of standard PF

– PF metric does not distinguish between traffic classes– No bit rate guarantee, i.e. no streaming services supported– Interactive service not prioritised against background one

• Idea of QoS aware HSPA scheduling (RAN1262)– QoS aware HSPA scheduling enabled with parameter HSPAQoSEnabled– HSDPA dynamic resource allocation must be enabled– Streaming services

Guaranteed bit rate set by RNC– Interactive IA & Background BG services

Operator can set nominal bit rate (target minimum bit rate)If not defined, service treated as best effort one

Operator can set service priorities, so that IA services are scheduled more often than BG onesServices belonging to same traffic class againscheduled according PF

HSPAQoSEnabledWCEL; 0..4;1; 0 = disabled0 = QoS prioritization is not in use for HS transport1 = QoS prioritization is used for HS NRT channels2 = HSPA streaming is in use (RAN1004)3 = HSPA CS voice is in use (RAN1689)4 = HSPA streaming and CS voice are in use


Application Aware RAN – NSN implementation

Application Aware RAN solution is implemented in 2 network elements GGSN and RNC

1. In GGSN: Core network based DPI (Deep Packet Inspection) provides application detection and inner (user) IP packet marking with DSCP (Differential Service Code Point - a field in the IPv4 and IPv6 header)

DSCP of user packet is marked based on PCC rule action

2. In RNC: Initial Scheduling Priority Indicator of the radio bearer is demoted or promoted in the RNC PDCP layer according to Deep Packet Inspection marking (DSCP marking).


Overview HS-PDSCHHigh-Speed Physical DL Shared Channel


HS-SCCHShared Control Channel for HS-DSCH

HS-SCCHShared Control Channel for HS-DSCH

associated DCH*Dedicated Channel

associated DCH*Dedicated Channel

HS-DPCCHDedicated Physical Control Channel (UL) for HS-DSCH

HS-DPCCHDedicated Physical Control Channel (UL) for HS-DSCH

Static power allocationTx power „fixed“Slowly adjusted in dependence on HS-SCCH Tx power

Dynamic power allocationAll power not needed for R99 services available for HSDPASlowly adjusted in dependence on R99 & HSDPA traffic

Fast power control in dependence on:- CQI- Feedback of UE

Fast power control parallel to DPCCH with offset for CQIACK/NACK

Inner loop PC basing DL TPC and CQI

WBTSUE

F-DPCH*Fractional Dedicated Physical Channel

F-DPCH*Fractional Dedicated Physical Channel

* F-DPCH can be allocated in DL only if SRB can be mapped to HSPA channels


HS-PDSCH Power Allocation

Static Power Allocation Dynamic Power Allocation

• PHSDPA ≤ PtxMaxHSDPA PHSDPA ≤ min(PtxMaxHSDPA, PtxCellMax)-

power allocated to R99 DCH & DL control channels• Fixed load target PtxTargetHSDPA Dynamically adjusted load target PtxTargetPS• Fixed overload threshold for R99 Overload threshold for R99 goes parallel to

load target:PtxTargetHSDPA + PtxOffsetHSDPA PtxTargetPS + PtxOffset

• In case of overload HSDPA might be In case of overload HSDPA power might be reduced,released immediately but usually service not released immediately

• Priorities distinguish between R99 & Priorities distinguish between interactive & background

• HSDPA users only users as well

PtxMaxHSDPAMaximum allowed HSDPA powerWCEL; 0..50 dBm; 0.1 dB; 43 dBm

PtxTargetHSDPA Target for transmitted non-HSDPA

powerWCEL; -10..50 dBm; 0.1 dB; 38.5 dBm

PtxOffsetHSDPAOffset for transmitted non-HSDPA powerWCEL; 0..6 dB; = 0.1 dB; 0.8 dB

HSDPADynamicResourceAllocationHSDPA Dynamic Resource Allocation RNFC; 0 = disabled; 1 = enabled

PtxCellMaxCell maximum transmission powerWCEL; 0 .. 50 dBm; 0.1 dB; 43 dBm

PtxOffsetOffset for transmitted powerWCEL; 0 .. 6 dB; 0.1 dB; 1 dB


• BTS may allocate all unused DL power up to maximum cell power• all power available after DCH traffic, HSUPA control & common channels can be used for

HSDPA

PtxNC

PtxNRT

PtxHSDPA

PtxMax = min (PtxCellMax, MaxDLPowerCapability)

PtxNonHSDPA

Dynamic HS-PDSCH Power Allocation (1/7)

PtxCellMaxCell maximum transmission power0..50 dBm; 0.1 dB; 43 dBm

MaxDLPowerCapability: 0..50 dBm; 0.1 dB; -


Dynamic HS-PDSCH Power Allocation (2/7)

No active HSDPA users• NRT DCH scheduling to

– PtxTarget + PtxOffset if HS-RACH isn’t set up in the cell

– PtxTargetPS if HS-RACH is set up in the cell

• RT DCH admission to PtxTarget

Active HSDPA users• NRT DCH scheduling to

PtxTargetPS • RT DCH admission to

– PtxTarget no RT HS-SDCH– PtxTargetTot at least 1 RT HS-DSCH

HSDPA activeNo HSDPA users No HSDPA users

PtxTarget + PtxOffset

PtxMax

PtxTargetPS

PtxNC

PtxNRT

PtxHSDPA

1

2

3

PtxNonHSDPA

PtxTotal


Dynamic HS-PDSCH Power Allocation (3/7)• Adjustable load target PtxTargetPS

– PtxTargetPSMin (minimum value)– PtxTargetPSMax (maximum value, also initial value, HS-RACH is set up in the cell)– PtxTargetPSMaxHSRACH (maximum value used if HS-RACH is set up in the cell)

PtxTargetPSMinMin DCH PS target for dynamic HSDPA pwr allocationWCEL; -10..50 dBm; 0.1 dB; 36 dBm

PtxTargetPSMaxMax DCH PS target for dynamic HSDPA pwr allocationWCEL; -10..50 dBm; 0.1 dB; 40 dBm

PtxTargetPSMaxHSRACHMax DCH target power level with HS-RACH for dynamic HSDPA pwr allocationWCEL; 0..40 dBm; 0.1 dB; 32767 dBm (Value set by the PtxTargetPSMax parameter used when the HS-RACH has been setup in the cell)

PtxNC

PtxNRT

PtxHSDPA

PtxMax

PtxNonHSDPA

PtxTargetPSMin (36 dBm)

PtxTargetPSMax (40 dBm)PtxTargetPS

PtxTargetPSMin-10..50 dBm; 0.1 dB; 36 dBm

PtxTargetPSMax-10..50 dBm; 0.1 dB; 40 dBm


Load Target Adjustment (6/7)

• Required information– Total power PtxTotal measured by Node B– Non HSDPA power PtxNonHSDPA measured by Node B– Both averaged according PSAveragingWindowSize (same parameter as for R99)

• Need for adjustment checked periodically according PtxTargetPSAdjustPeriod• If adjustment needed

– Increase by PtxTargetPSStepUp in case of DCH congestion– Decrease by PtxTargetPSStepDown in case of HSDPA congestion

PSAveragingWindowSize Load measurement averaging window size for PS WBTS; 1..20; 1; 4 scheduling periods

PtxTargetPSAdjustPeriodDCH PS target adjust period for dyn HSDPA power alloc; WBTS; 1..255; 1; 5 RRI periods

PtxTargetPSStepUpDCH PS target step up for dynamic HSDPA pwr alloc.WCEL; 0..5; 0.1; 1 dB

PtxTargetPSStepDownDCH PS target step down for dynamic HSDPA pwr alloc.WCEL (0..5 dB) ( = 0.1 dB) (1 dB)


Actions in Case of Congestion (7/7)

DCH congestion only• Increase PtxTargetPS by PtxTargetPSStepUp, if currently below ideal load target (but not above PtxTargetPSMax)

HSDPA congestion only• Decrease PtxTargetPS by PtxTargetPSStepDown, if currently above ideal load target (but not below PtxTargetPSMin)

Both DCH & HSDPA congestion• Increase PtxTargetPS, if currently below ideal load target• Decrease PtxTargetPS, if currently above ideal load target


Static & Dynamic Allocation (1/3)

HSPDSCHCodeSet11010 10100

100000

HSPDSCHCodeSet00000 10100

100000

HSPDSCHCodeSet00000 00000 100000

Additionally required HSDPADynamicResourceAllocation =

enabled

Number of HS-

PDSCH codes (full

set)

HSDPA

15

Codes

HSDPA

10

Codes

Static

code

allocation

5 X X X

6 - - -

7 - - -

8 X X -

9 - - -

10 X X -

11 - - -

12 X - -

13 - - -

14 X - -

15 X - -



Dynamic code allocation applied if:• HSDPA dynamic resource allocation

enabled (HSDPADynamicResourceAllocation)

• Maximum number of codes > minimum number (HSPDSCHCodeSet)

• BTS capable of 10/15 codes• HSDPA service starts with minimum

number of codes defined by HSPDSCHCodeSet

• Cell-specific scheduler reserves HS-SCCH codes from the spreading code tree according to MaxNbrOfHSSCCHCodes

If HSDPA dynamic resource allocation disabled, 5 codes are available only

SF=8

SF=4

SF=2

SF=1

SF=161514131211109876543210

HS-PDSCH

………. ……….

SF=8

SF=4

SF=2

SF=1

SF=161514131211109876543210

HS-PDSCHRel-99 channels(& HS-SCCH)

Rel-99 code area (& HS-SCCH)

Shared code area

Dedicated HS-PDSCH

SF=8

SF=4

SF=2

SF=1

SF=161514131211109876543210

HS-PDSCH

………. ……….

SF=8

SF=4

SF=2

SF=1

SF=161514131211109876543210

HS-PDSCHRel-99 channels(& HS-SCCH)

Rel-99 code area (& HS-SCCH)

Shared code area

Dedicated HS-PDSCH code area



128 128128

Available CCAllocated CC Blocked CC

SF16

SF32 32

SF64 64 64 64

SF256 256 256 256 256 256 256 256 256 256 256256 256256 256 256

128 128 128 128 128 128 128SF128

+14 x SF16

HS-PDSCH

CPICH AICH

S-CCPCH1

S-CCPCH2HS-SCCH HS-SCCH HS-SCCH

32

64 64

256 256 256 256 256 256 256 256

128 128 128 128

SF16

E-RGCH E-HICH

E-AGCH

Maximum of 14 HS-PDSCH codes possible with 3 HS-SCCH & HSUPA

P-CCPCH PICH


Dynamic Allocation Procedure (1/2)

Periodic upgrade• HSDPA service starts with minimum number of codes• RNC attempts periodic upgrade according the timer

HSPDSCHAdjustPeriod if• Number of currently allocated HS-PDSCH codes < maximum allowed

number supported by BTS capability• Free SF 16 codes adjacent to currently allocated ones available• After upgrade enough SF 128 codes available according

HSPDSCHMarginSF128• If all conditions are fulfilled, the next greater value from HS-PDSCH code

set is taken

Periodic downgrade• RNC attempts periodic downgrade according the timer

HSPDSCHAdjustPeriod if• Number of currently allocated HS-PDSCH codes > minimum allowed

number• Not enough SF 128 codes available according HSPDSCHMarginSF128

• If all condition fulfilled, the next lower value from HS-PDSCH code set is taken

HSPDSCHMarginSF128

WCEL; 0..128; 1; 8# SF128 codes to be available after Code

upgrade

HSPDSCHAdjustPeriodRNHSPA; 1..60; 1; 10s


Dynamic Allocation Procedure (2/2)N

um

be

r o

f a

llo

ca

ted

SF

16

co

de

s

DPCHOverHSPDSCHThresholdset relative to max. number of codes

6789101112131415 Maximum code

set

5

• Code congestion events– RT request congested due to lack of code HS-PDSCH downgrade in any case– NRT request congested due to lack of code HS-PDSCH downgrade only, if actually for HSDPA

too much SF 16 codes in use according DPCHOverHSPDSCHThreshold

• Limitations of congestion triggered downgrade– Not below minimum allowed number of HS-PDSCH codes– Highest still possible number of codes according HSPDSCHCodeSet is taken

Minimum code set

HSPDSCHCodeSet

WCEL; 5..15; 1; 5

DPCHOverHSPDSCHThreshold

WCEL; 0..10; 1; 5

Code tree optimization• Code tree optimization procedure tries to re-arrange DPCH

codes to make room for HS-PDSCH code upgrade• DPCHs having SRB DCH only are not allowed to be re-arranged

CodeTreeOptimisationWCEL; 0 = disabled; 1 = enabled


HSPDSCHCodeSet

WCEL; 5..15; 1; 5


DPCHOverHSPDSCHThreshold

WCEL; 0..10; 1; 5


HSDPA Mobility

Serving Cell Change SCC (1/5): CandidateInitial cell selection• 1 cell active only: just attempt to establish service

• More than 1 cell active– Initial selection of Serving Cell based on latest reported Ec/I0

– To be candidate, HSDPA capable cell must fulfil following condition:

– Serving cell is chosen in order of EC/I0

– If allocation of HS-DSCH fails due to any reason, next best candidate cell is attempted

EC/I0 (active cell*) ≥ EC/I0 (best cell) – HSDPAServCellWindow

HSDPAServCellWindowCPICH Ec/Io window for serving HS-

DSCH cell selectionRNMOBI; 0..6; 0.5; 2 dB

* Serving Cell

Max. allowed difference between the best cell in the Active Set & the Serving HSDSCH cell. If Serving HS-DSCH cell out of this window Serving HS-DSCH cell change procedure initiated.

Methods to handle HSDPA mobility• Serving HS-DSCH cell change• Cell reselection with HS-DSCH - FACH channel type switching

HSDPAMobilityServing HS-DSCH cell change & SHO on/off

switchRNFC; 0 = HSDPA cell reselection 1 = Serving HS-DSCH cell change


Directed RRC Connection Setup

Enhanced functionality• More than 2 layers supported• Can be restricted to certain types of

services• Load balancing applied• R99 directed RRC connection setup

simultaneously supported• Layering in Cell_FACH supported

(same rules as for RRC con. setup)

HSDPALayeringCommonChEnabled HSDPA layering for UEs in common channels enabled

WCEL; 0 = disabled; 1 = enabled

Basic functionality• Only for 2 layers• Service (cause for RRC connection

setup) not considered• Load of target layer not

considered• Cannot be used simultaneously

with

R99 directed RRC connection setup

• Layering in Cell_FACH supported

(same rules as for RRC con. setup)

Basic feature• Target

– R5 or newer UEs directed from non-HSDPA supporting carrier to HSDPA supporting one

– R99 or R4 UEs directed from HSDPA supporting carrier to non-HSDPA supporting one

– Feature works within same sector defined by SectorID

• Required parameter settings– DirectedRRCForHSDPALayerEnabled =

enabled– DirectedRRCForHSDPALayerEnhanc =

disabled

DirectedRRCForHSDPALayerEnabled

WCEL; 0 = disabled; 1 = enabled

DirectedRRCForHSDPALayerEnhancRNMOBI; 0 = disabled; 1 =

enabled

SectorIDWCEL; 0..12; 1; 0 = cell not

belonging to any sector


Enhanced feature• Non-HSDPA UEs

– Directed away from HSDPA capable cell if Load of the target cell not too big (i.e. R99 load balancing

back to source cell not triggered)

• HSDPA UEs– Directed away from non-HSDPA capable cell if

Establishment cause indicated by UE allowed in HSDPA layer Not too much HS-DSCH users in target cell

– Directed to other HSDPA capable cell if Load balancing required Establishment cause indicated by UE allowed in HSDPA layer

• HSUPA UEs– Same rules as for HSDPA UEs, but additionally

Directed to HSUPA capable cell if possible Not directed away from HSUPA capable cell

Directed RRC Connection Setup

HSDPA RRM

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