HSUPA Description(2008!11!30)

7/27/2019 HSUPA Description(2008!11!30)

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RANHSUPA Description

Issue 03

Date 2008-11-30

Huawei Proprietary and Confidential

Copyright Huawei Technologies Co., Ltd


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Huawei Technologies Co., Ltd. provides customers with comprehensive technical support and service. Forany assistance, please contact our local office or company headquarters.

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Copyright Huawei Technologies Co., Ltd. 2008. All rights reserved.

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HSUPA Description Contents

Issue 03 (2008-11-30) Huawei Proprietary and Confidential


i

Contents

1 HSUPA Change History ...........................................................................................................1-1

2 HSUPA Introduction.................................................................................................................2-1

3 HSUPA Principles......................................................................................................................3-1

3.1 HSUPA Protocol Architecture ............................................................ ........................................................... 3-13.2 HSUPA Channel Mapping....................................................................................... ......................................3-2

3.2.1 Mapping of Services onto The E-DCH................................................................................................3-2

3.2.2 Mapping of Logical Channels onto Transport Channels......................................................................3-2

3.2.3 Mapping of Transport Channels onto Physical Channels.....................................................................3-3

3.3 HSUPA Physical Channels............................................................................................................................3-4

3.3.1 E-DPCCH ........................................................... ................................................................ .................3-4

3.3.2 E-DPDCH...................................................................... ............................................................... .......3-6

3.3.3 E-AGCH ............................................................. ................................................................ .................3-6

3.3.4 E-RGCH...............................................................................................................................................3-9

3.3.5 E-HICH..............................................................................................................................................3-12

3.4 HSUPA Physical Channel Timing ........................................................... .................................................... 3-13

3.4.1 E-DPDCH/E-DPCCH Timing Relative to the DPCCH ........................................................... ..........3-13

3.4.2 E-AGCH Timing Relative to the P-CCPCH................................................................... ...................3-13

3.4.3 E-RGCH Timing Relative to the P-CCPCH ................................................................... ...................3-14

3.4.4 E-HICH Timing Relative to the P-CCPCH........................................................................................3-15

3.4.5 Association Between Frames of Different Physical Channels ........................................................... 3-15

3.5 HSUPA Key Technologies.................................................................. ......................................................... 3-17

3.5.1 HSUPA HARQ..................................................... ............................................................... ...............3-17

3.5.2 HSUPA Short TTI .......................................................... ................................................................ ....3-19

3.5.3 HSUPA Fast Scheduling ............................................................ ........................................................ 3-19

3.6 MAC-e PDU Generation.............................................................................................................................3-19

3.6.1 MAC-e PDU Overview......................................................................................................................3-19

3.6.2 MAC-e PDU Generation Process.......................................................................................................3-20

3.6.3 MAC-e PDU Encapsulation...............................................................................................................3-25

4 HSUPA Algorithms ...................................................................................................................4-1

4.1 Overview of HSUPA Related Algorithms ............................................................... ......................................4-1

4.1.1 Algorithm of HSUPA Fast Scheduling........................... ................................................................ ......4-1

4.1.2 Algorithm of Flow Control ........................................................ .......................................................... 4-1


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4.1.3 Algorithm of CE Allocation ...................................................... ........................................................... 4-1

4.1.4 Relation Among HSUPA Algorithms........ ................................................................ ...........................4-2

4.2 HSUPA Fast Scheduling................................................................................................................................4-2

4.2.1 Overview of HSUPA Scheduling ......................................................... ................................................4-2

4.2.2 User Queuing in the Scheduling Algorithm.............................................................. ...........................4-4

4.2.3 AG UP Processing in the Scheduling Algorithm..................................................................................4-6

4.2.4 RG UP Processing in the Scheduling Algorithm................................................. .................................4-9

4.2.5 GBR Processing in the Scheduling Algorithm.....................................................................................4-9

4.2.6 MBR Processing in the Scheduling Algorithm .............................................................. ....................4-10

4.3 HSUPA Flow Control..................................................................................................................................4-11

4.3.1 Overview of HSUPA Flow Control........................................................................... ......................... 4-11

4.3.2 Adjusting the Maximum Available Bandwidth of the Iub Port .......................................................... 4-12

4.3.3 Adjusting the Available Bandwidth of HSUPA................ .................................................................. 4-14

4.3.4 Handling Iub Buffer Congestion........................................................................................................4-14

4.4 Dynamic CE Resource Management ................................................................. .........................................4-15

4.5 Other HSUPA Related Algorithms ...................................................................... ........................................4-20

4.5.1 Mapping of Service to HSUPA................................................................. .........................................4-20

4.5.2 HSUPA over Iur ............................................................. ................................................................ ....4-22

4.5.3 HSUPA Cell Load Control.................................................................................................................4-24

4.5.4 HSUPA DCCC............................................................... ................................................................ ....4-24

4.5.5 HSUPA Power Control.............................. ................................................................ .........................4-25

4.5.6 HSUPA Mobility Management ................................................................. .........................................4-25

4.5.7 HSUPA Directed Retry .............................................................. ........................................................ 4-26

5 HSUPA Parameters....................................................................................................................5-1

6 HSUPA Reference Documents ................................................................................................6-1

prietary and Confidential


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HSUPA Description 1 HSUPA Change History



1-1

1 HSUPA Change HistoryHSUPA Change History provides information on the changes between different document

versions.

Document and s

T nt and p t versions

Product Version

able 1-1Docume roduc

Document Version RAN Version RNC Version NodeB Version

03 (2008-11-30) 10.0 V200R010 V200R010

V100R010

02 (2008-07-30) 10.0 V200R010C01B061 V100R010C01B050

V200R010C01B041

01 (2008-05-30) 10.0 V200R010C01B051 V100R010C01B049

V200R010C01B040

Draft (2008-03-20) 10.0 V200R010C01B050 V100R010C01B045

Ther

Feature change: refers to the change in the HSUPA feature of a specific product version.

Editorial change: refers to changes in information that has already been included, or the

ion.

03 (2008-11-30

This is the document for the second commercial release of RAN10.0.

Compared with 01(2008-07-30) of RAN10.0, issue 03 (2008-11-30) of RAN10.0 incorporates

t ib following table.

e are two types of changes, which are defined as follows:

z

z

addition of information that was not provided in the previous vers

)

he changes descr ed in the

Change Type Change Description Parameter Change

Feature change NoneNone.


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Change Type Change Description Parameter Change

Mapping of Service to HSUPA is

added to 4.5 Other HSURelated Alg

PAorithm.

NoneEditorial change

HSDPA Over Iur is added to 4.5

Other HSUPA RelatedAlgorithm.

None

02 (2008-07-30

This is the document for the first commercial release of RAN10.0.

C with N10.0, issu RAN10.0inc ates the changes described in the following table.

)

omparedorpor

01 (2008-05-30) of RA e 02 (2008-07-30) of

Change Change Description Parameter ChangeType

Featurechange Management is optimized For

details, refer to 4.4 Dynamic

CE Resource Management

e

d as follows:

e Index

CH 3-Index-Step Threshold

z

E-RGCH 2-Index-Step Threshold

Dynamic CE Resource The parameters that are changed to bnon-configurable are liste

z Happy bit delay time

z HSUPA service rate extend scale

z E-TFCI Tabl

z E-RG

Editorial

change

A parameter list is added. See

chapter 5 HSUPA Parameters.

None.

01 (2008-05-30

This is the document for the first commercial release of RAN10.0.

C with N10.0, issue N10.0inc ates the changes described in the following table.

)

omparedorpor

draft (2008-03-20) of RA 01 (2008-05-30) of RA


Featurechange

None. eno igurable are listed as follows:

for E-DCH

duling Info power

offset

The parameters that are changed to bn-conf

z HARQ Info

z HSUPA Sche

Editorialchange

G

removed because of the creation

None.eneral documentation change:

z The HSUPA Parameters is



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HSUPA Description 1 HSUPA Change History



1-3


of RAN10.0 parameter reference.

z The structure is optimized.

Draft (2007-03-2

T draft of the document for the first commercial release of RAN10.0.

C wit 6.1, this issue incorporates the chad in th

0)

his is a

omparedescribed

h issue 03 (2008-01-20) of RAN ngese following table:

Change Description ParamChange eterType Change

SRB can be carried on E-DCH. None.

The algorithm ofHSUPA scheduled transmission is changed. None.

T None.he algorithm ofHSUPA flow control is changed.

Feature

The algorithm ofHSUPA CE scheduling is introduced. None.

change

Editorialchange

General documentation change is as follows:

z Implementation information has been moved to a separatedocument. For detailed information on implementing HSUPA,

refer to Configuring HSUPA inRAN Feature Configuration

Guide.

None.


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HSUPA Description 2 HSUPA Introduction



2-1

2 HSUPA IntroductionHSUPA (High Speed Uplink Packet Access) is an

(UL) high speed data transmission solution, H

important feature of 3GPP R6. As an uplink

SUPA provides a theoretical maximum uplink

Huaw

The as follows:

z e physical layer: It is used to achieve rapid retransmission for erroneously

heduling: It is used to increase resource utilization and

U

riber experience with high-speed services

ntrol: maximizing resource utilization and cell throughput

roving the QoS of the network

cell

ter handoverS)

r with R99

o 6

ol

z Iub flow control

MAC-e rate of 5.73 Mbit/s on the Uu interface. The MAC-e peak data rate supported byei RAN10.0 is 5.73 Mbit/s.

main features of HSUPA are

z 2 ms short frame: It enables less Round Trip Time (RTT) in the Hybrid AutomaticRepeat reQuest (HARQ) process, which is controlled by NodeB. It also shortens thescheduling response time.

HARQ at threceived data packets between the User Equipment (UE) and NodeB.

z NodeB-controlled UL fast scefficiency.

HS PA improves the performance of the UMTS network in the following aspects:

z Higher UL peak data rate

z Lower latency: enhancing the subsc

z Faster UL resource co

z Better Quality of Service (QoS): imp

z UL peak rate: 5.73 Mbit/s per user

z 10 ms and 2 ms TTI

z Maximum 60 HSUPA users per

z

Soft handover and sofz Multiple RABs (3 P

z Dedicated/co-carrie

z UE categories 1 t

z Basic load contr

z OLPC for E-DCH

z CE scheduling

z Power control of E-AGCH/E-RGCH/E-HICH


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Network Elem

The foll le s lem s) in

Table 2- nvo d in HSUPA

ents Involved

owing tab describe the Network E ents (NE involved HSUPA.

1NEs i lveUE NodeB RNC MSC Server MGW SGSN GGSN HLR

N

z = NE involved

UE = User Equipment, RNC = Radio Network Controller, MSC Server = Mobile Service SwitchingCenter Server, MGW = Media Gateway, SGSN = Serving GPRS Support Node, GGSN = Gateway

GPRS Support Node, HLR = Home Location Register

OTE

z = NE not involved

Impact

ance

provide a significant

ghput, a shortere

z

Th

The implementation of HSUPA requires the support of power control, load control,admission control, and mobility management.

HSUPA and the other features have an impact on each other. For detailed information,see Other HSUPA Related Algorithms.

z Impact on System Perform

Compared with 3GPP R99, 3GPP R6 introduces HSUPA to

enhancement in the uplink in terms of peak data rate and cell throulat ncy, and a good balance between downlink and uplink.

Impact on Other Features

e impact of HSUPA on the other features is as follows:

HSUPA does not affect the effectiveness of the other features.



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HSUPA Description 3 HSUPA Principles



3-1

3 HSUPA PrinciplesThe principles of HSUPA cover the technical aspects of the feature:

z HSUPA Physical Channel Timing

z HSUPA Key Technologies

3.1 HSUPA

rotocol architecture of HSUPA.

z HSUPA Protocol Architecture

z HSUPA Channel Mapping

z HSUPA Physical Channels

z MAC-e PDU Generation

Protocol Architecture

HSUPA Protocol Architecture describes the p

Figure 3-1 shows the HSUPA protocol architecture.

Figure 3-1Protocol architecture of HSUPA

To e SUPA is implemented in the following ways:

e multiplexing, and E-DCH Transport Format

nhance the Access Stratum (AS), H

z A new MAC entity (MAC-es/MAC-e) is added to UE below the MAC-d to handle

HARQ retransmission, scheduling, MAC-Combination (E-TFC) selection.


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z A new MAC entity (MAC-e) is added to NodeB to handle the HARQ retransmissionscheduling, and MAC-e demu

,ltiplexing.

added to SRNC to combine signals from differentliver data to the MAC-d in sequence.

Step 1 es/MAC-e of the UE sends the MAC-e PDUs to the physical layer (PHY) of UE.

FP to the MAC-es of SRNC.

Step 3 CH FP of Iub interface controls the data flow between NodeB MAC-e and SRNCMAC-es.

Step 4

dio Access Network (UTRAN) supports higher-rateitched Core Network (PS CN) requires a higher rate

ission, and switching.

3.2 HSUPA C

U

3.2.1 Mappi

service onto

the E-DCH according to the factors, such as, the traffic class, service rate, scheduling scheme,

3.2.2 Mapping of Logical Channels onto Transport Channels

Both Dedicated Control Channel (DCCH) and Dedicated Traffic Channel (DTCH) can bemapped onto the E-DCH in HSUPA.

z A new MAC entity (MAC-es) isNodeBs in soft handover and de

z A new transport channel (E-DCH) is added to transfer data blocks between NodeBMAC-e and SRNC MAC-es.

The HSUPA data flow is as follows:

The MAC-

Step 2 The MAC-e of NodeB sends the MAC-es PDUs through E-DCH

The E-D

The MAC-es of SRNC sends MAC-d PDUs to SRNC MAC-d.

----End

With HSUPA, the Universal Terrestrial Ratransmission. Accordingly, the Packet Swof service assignment, user plane transm

hannel Mapping

HS PA Channel Mapping describes the following:

z

Mapping services information on the E-DCH,z Mapping of logical channels onto the transport channels

z Mapping of transport channels onto the physical channels

ng of Services onto The E-DCH

When the UE sends a service request, the RNC determines whether to map the

cell HSUPA capability and UE HSUPA capability.

For detailed information on mapping of signaling and traffic onto transport channels, see

Mapping of Signaling and Traffic onto Transport Channels in Radio Bearers.



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3-3

Figure 3-2Mapping of logical channels onto transport channels on the UE side

Figure 3-3Mapping of logical channels onto transport channels on the UTRAN side

3.2.3 Mapping of Transport Channels onto Physical Channels

After the coding and multiplexing on the E-DCH are performed, the subsequent data streams

are mapped sequentially (first in, first out) and directly onto the physical channels.


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Figure 3-4Mapping of transport channels onto physical channels

3.3 HSUPA Physical Channels

HSUPA Physical Channels describes five types of HSUPA physical channels:

z E-DPCCH

z E-DPDCH

z E-AGCH

z E-RGCH

z E-HICH

3.3.1 E-DPCCH

The E-DCH Dedicated Physical Control Channel (E-DPCCH) carries the control informationassociated with the E-DCH. Each radio link has at most one E-DPCCH. The spreading factor

of the E-DPCCH is 256.



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3-5

Figure 3-5Frame structure of the E-DPCCH

The E-DPCCH carries the following control information:

z Retransmission Sequence Number (RSN): 2 bits

z E-TFC Indicator (E-TFCI): 7 bits

z Happy Bit: 1 bit

Retransmission Sequence Number (RSN): 2 Bits

RSN is transmitted on the E-DPCCH and used to convey the uplink HARQ transmission

number.

E-TFCI: 7 Bits

E-TFCI is used on the current E-DPDCH. There are four transport block size tables defined in

3GPP 25.321. Each TTI has two tables, the details for which are as follows:

z 2 ms TTI E-DCH Transport Block Size Table 0




Table 0 or Table 1 is selected according to the signaling from the RNC.The E-TFCI Table

Index is 0 for Voip service and SRB for 2ms TTI and 1 for all the others. With the table, theE-TFCI can be mapped to a transport block size.

Happy Bit: 1 Bit

Happy Bit is a single bit field that is, passed from the MAC to the physical layer for the

E-DPCCH inclusion. This field takes two values: Unhappy and Happy, which indicatewhether the UE wants more resources.

The Unhappy value indicates a higher data rate than that supported by the current SG, due to

the sufficient data in the buffer and enough power in the UE. Otherwise, the Happy Bit is setto Happy.


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For every E-DCH transmission, the Happy Bit is set to Unhappy if the following conditionsare met:

z The UE transmits as much scheduled data as allowed by the current SG during E-TFCselection.

z The UE has enough power to transmit data at a higher rate.

z Based on the same power offset as the one selected during E-TFC selection to transmit

data in the same TTI as the Happy Bit, the Total E-DCH Buffer Status (TEBS) mayrequire more than Happy bit delay time which equals to 50 ms to be transmitted with thecurrent SG multiplied by the ratio of the number of active processes to the total numberof processes.

The ratio mentioned in the third criteria is always 1 for 10 ms TTI.

3.3.2 E-DPDCH

The E-DCH Dedicated Physical Data Channel (E-DPDCH) carries the data associated with

the E-DCH. Each radio link can have none, one, or several E-DPDCHs. The spreading factorof the E-DPDCH ranges from 2 to 256.

RAN10.0 provides a maximum of four E-DPDCHs with two SF4s and two SF2s.

Figure 3-6Frame structure of the E-DPDCH

Generally, the E-DPDCH and the E-DPCCH are transmitted simultaneously, except with the

power scaling as described in 3GPP TS 25.214, the E-DPCCH is transmitted discontinuously.

3.3.3 E-AGCH

The E-DCH Absolute Grant Channel (E-AGCH) carries AGs for uplink E-DCH scheduling.The E-AGCH is a common downlink physical channel with a fixed rate of 30 kbit/s. The

spreading factor of the E-AGCH is 256.

The E-AGCH is a shared channel for all HSUPA UE in the serving E-DCH cell.



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3-7

Figure 3-7Frame structure of the E-AGCH

An E-DCH AG has to be carried by one E-AGCH subframe or one E-AGCH frame,

depending on the E-DCH TTI is 2 ms or 10 ms.

The information transmitted on the E-AGCH includes a 5-bit field of the AG value and a 1-bit

field of the AG scope.

z The AG value indicates the maximum power ratio of the E-DPDCH to the correspondingDPCCH. The mapping of AG values is described in Table 3-1.

z The AG scope indicates whether the HARQ process activation or deactivation will affectone or all of the processes. The AG scope can take two different values: "Per HARQ

process" or "All HARQ processes". "Per HARQ process" means that the AG is for one HARQ process.

"All HARQ processes" means that the AG is for all HARQ processes.

When the E-DCH is configured with 10 ms TTI, only the value "All HARQ processes" is

valid.

For detailed information on SG update, see HSUPA Serving Grant Update (subclause 11.8.1.3

in 3GPP 25.321).

The RNC-assigned sequence of 16-bit CRC on the E-AGCH is masked with either a primaryor a secondary E-RNTI. Here, the E-RNTI stands for E-DCH Radio Network Temporary

Identifier.

z The primary E-RNTI is unique for each UE.

z The secondary E-RNTI is usually for a group of UEs.

When the UE demodulates the E-AGCH, the E-AGCH will again mask the CRC with the

primary or secondary E-RNTI. Only the UE having the same E-RNTI can demodulate the

information correctly.

Only the primary E-RNTI is used in the current RAN version.


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Table 3-1Mapping of AG values

Absolute Grant Value Index

(168/15)2

x 6 31

(150/15)2

x 6 30

(168/15)2

x 4 29

(150/15)2

x 4 28

(134/15)2

x 4 27

(119/15)2

x 4 26

(150/15)2

x 2 25

(95/15)2

x 4 24

(168/15)2 23

(150/15)2

22

(134/15)2

21

(119/15)2

20

(106/15)2

19

(95/15)2

18

(84/15)2

17

(75/15)2 16

(67/15)2

15

(60/15)2

14

(53/15)2

13

(47/15)2

12

(42/15)2

11

(38/15)2

10

(34/15)2 9

(30/15)2

8

(27/15)2

7

(24/15)2

6

(19/15)2

5

(15/15)2

4

(11/15)2

3

(7/15)2 2



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3-9

Absolute Grant Value Index

ZERO_GRANT 1

INACTIVE 0

3.3.4 E-RGCH

The E-DCH Relative Grant Channel (E-RGCH) carries RGs for uplink E-DCH scheduling.The E-RGCH is a dedicated downlink physical channel with a fixed rate of 60 kbit/s. The

spreading factor of the E-RGCH is 128.

Figure 3-8Frame structure of the E-RGCH

An RG is transmitted in 3, 12, or 15 consecutive slots. Each slot carries a sequence of 40binary values.

z If the cell transmitting the E-RGCH is in the serving E-DCH Radio Link Set (RLS), then3 or 12 slots are used, depending on the E-DCH TTI is 2 ms or 10 ms.

z If the cell transmitting the E-RGCH is not in the serving E-DCH RLS, 15 slots are used.

The RG commands are mapped to the RG values, as described in the following table.

Table 3-2Mapping of RG commands

RGCommand

RG Value (for ServingE-DCH RLS)

RG Value (for Non-ServingE-DCH RL)

UP 1 Not allowed

HOLD 0 0

DOWN 1 1


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When the UE receives an RG command, the SG is adjusted upwards or downwards by onestep. The step can be 1, 2, or 3 in the Scheduling Grant Table according to the current SGvalue, E-RGCH 3-Index-Step Threshold whose value is 17 for 2ms TTI and 9 for 10ms TTI,

and E-RGCH 2-Index-Step Threshold. Wose value is 18 for 2ms TTI and 12 for 10ms TTI.The Scheduling Grant Table is provided in Table 3-3.

When the SG needs to be determined due to E-RGCH signaling:

z The UE determines the lowest power ratio and the corresponding index in theScheduling Grant Table: SGIndexLUPR. The lowest power ratio is in the Scheduling GrantTable (Table 3-3), and is equal to, or higher than the reference_ETPR.

The reference_ETPR is the power ratio of E-DPDCH to DPCCH. The ratio is used for

the E-TFC selected for the previous TTI in this HARQ process and calculated by theamplitude ratios prior to the quantization according to 4.5.5 HSUPA Power Control.

z If the UE receives a serving RG "UP", the UE determines the SG (based on the

"3-index-step threshold" and "2-index-step threshold" configured by higher layers) asfollows:

z If SGIndexLUPR< 3-index-step threshold, then SG = SG [MIN (SG + 3, 37)]LUPR .

z For example, if SGIndexLUPR= 15 and 3-index-step threshold = 20, then the new SGindex is 18.

z If 3-index-step threshold SGIndexLUPR< 2-index-step threshold, then SG = SG [MIN(SG + 2, 37)]LUPR .

z For example, if SGIndexLUPR= 21 and 2-index-step threshold = 25, then the new SGindex is 23.

z If SGLUPR 2-index-step threshold, then SG = SG [MIN (SG + 1, 37)]LUPR .

z For example, if the SGIndexLUPR = 28 and 2-index-step threshold = 25, then the new SGindex is 29.

z If the UE receives an RG "DOWN", then SG = SG[MAX (SG - 1, 0)]LUPR .z SG = SG[SGIndex] which means to get an SG from the Scheduling Grant Table

according to the SGIndex.

Table 3-3Scheduling Grant Table

Index Scheduled Grant

37 (168/15)2

x 6

36 (150/15)2

x 6

35 (168/15)2

x 4

34 (150/15)2

x 4

33 (134/15)2

x 4

32 (119/15)2

x 4

31 (150/15)2

x 2

30 (95/15)2

x 4

29 (168/15)2

28 (150/15)2



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Index Scheduled Grant

27 (134/15)2

26 (119/15)2

25 (106/15)2

24 (95/15)2

23 (84/15)2

22 (75/15)2

21 (67/15)2

20 (60/15)2

19 (53/15)2

18 (47/15)2

17 (42/15)2

16 (38/15)2

15 (34/15)2

14 (30/15)2

13 (27/15)2

12 (24/15)2

11 (21/15)2

10 (19/15)2

9 (17/15)2

8 (15/15)2

7 (13/15)2

6 (12/15)2

5 (11/15)2

4 (9/15)2

3 (8/15)2

2 (7/15)2

1 (6/15)2

0 (5/15)2


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3.3.5 E-HICH

The E-DCH Hybrid ARQ Indicator Channel (E-HICH) carries uplink E-DCH HARQ

acknowledgement indicators. The E-HICH is a dedicated downlink physical channel with afixed rate of 60 kbit/s. The spreading factor of the E-HICH is 128.

The frame structure of the E-HICH is the same as that of the E-RGCH. An HARQ

acknowledgement indicator is transmitted in 3 or 12 consecutive slots and in each slot asequence of 40 binary values is transmitted as follows:

z 3 slots are used for the UE with 2 ms E-DCH TTI.

z 12 slots are used for the UE with 10 ms E-DCH TTI.

Figure 3-9Frame structure of the E-HICH

The ACK and NACK mappings on the E-HICH are described in the following table. For the

RLSs that do not contain the serving E-DCH cell, the NACK is transmitted discontinuously.

Table 3-4Mapping of HARQ acknowledgement

Command HARQ AcknowledgementIndicator

ACK +1

NACK (for the RLSs not containing the serving E-DCHcell)

0

NACK (for the RLS containing the serving E-DCH cell) 1

When an ACK and an NACK are received at the same time, the UE combines them as shown

in the following table.



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Table 3-5ACK/NACK combining

TransmissionData Type

ACK/NACKfrom ServingRLS

ACK/NACKfromNon-Serving

RLs

Operation of UE

All data ALL NACK ALL NACK The UE performs HARQ

(re)transmissions until the

maximum number oftransmissions is reached.

All data At least one

ACK

Either ACK or

NACK

ACK

High-level dataonly

ALL NACK At least oneACK

ACK

Higher layer dataand SI triggeredby an event ortimer

ALL NACK At least oneACK

The UE notifies the SchedulingInformation Reporting functionthat the Scheduling Information

is not received by the serving the

RLS, flushes the packet, andincludes the schedulinginformation with new datapayload in the next packet.

SI only ALL NACK Either ACK or

NACK

The UE performs HARQ

(re)transmissions until an ACK

from the RLS containing theserving cell is received or until

the maximum number oftransmissions is reached.

3.4 HSUPA Physical Channel Timing

The Primary Common Control Physical Channel (P-CCPCH), on which the cell SystemFrame Number (SFN) is transmitted, is used as a timing reference for all the physical

channels, directly for the downlink and indirectly for the uplink.

3.4.1 E-DPDCH/E-DPCCH Timing Relative to the DPCCH

The timing of the E-DPCCH and all the E-DPDCHs transmitted from the UE is the same asthat of the uplink DPCCH.

3.4.2 E-AGCH Timing Relative to the P-CCPCH

The E-AGCH frame offset from the P-CCPCH should be = 5120 chips.


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Figure 3-10E-AGCH timing relative to the P-CCPCH

3.4.3 E-RGCH Timing Relative to the P-CCPCH

The timing of the E-RGCH relative to the P-CCPCH is shown in the following figure.

Figure 3-11E-RGCH timing relative to the P-CCPCH

If the E-RGCH is transmitted to the UE, and the cell transmitting the E-RGCH is in the

serving E-DCH RLS, the E-RGCH frame offset should be as follows:

z If the E-DCH TTI is 10 ms, the E-RGCH frame offset from the P-CCPCH ischips.

In this case, is the DPCH frame offset from the P-CCPCH.

z If the E-DCH TTI is 2 ms, the E-RGCH frame offset from the P-CCPCH ischips.



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If the E-RGCH is transmitted to the UE, and the cell transmitting the E-RGCH is not in the

serving E-DCH RLS, the E-RGCH frame offset from the P-CCPCH should be =

5120 chips.

3.4.4 E-HICH Timing Relative to the P-CCPCH

The timing of the E-HICH relative to the P-CCPCH is shown in the following figure.

Figure 3-12E-HICH timing relative to the P-CCPCH

z If the E-DCH TTI is 10 ms, the E-HICH frame offset from the P-CCPCH should

be chips.

z If the E-DCH TTI is 2 ms, the E-HICH frame offset from the P-CCPCH should be

chips.

3.4.5 Association Between Frames of Different Physical Channels

10 ms E-DCH TTI

For each cell in the E-DCH active set: The UE associates the control information received

through the E-HICH frame SFNi with the data transmitted in the E-DPDCH frame SFNi-3.

The following figure shows an example of timing of the E-HICH with 10 ms TTI.


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Figure 3-13E-HICH timing relative to the P-CCPCH

For each cell that belongs to the serving E-DCH RLS: The UE first takes into account the

E-DCH control information received through the E-RGCH frame SFNi in the higher layer

procedures that correspond to the E-DCH transmission in the E-DPDCH frame SFNi+1.

For each cell that does not belong to the serving E-DCH RLS: The UE first takes into account

the E-DCH control information received through the E-RGCH frame SFNi in the higher layerprocedures that correspond to the E-DCH transmission in the E-DPDCH frame SFNi+1+s,

Where,

For the E-AGCH frame: The UE first takes into account the E-DCH control informationreceived through the E-AGCH frame SFNi in the higher layer procedures that correspond to

the E-DCH transmission in the E-DPDCH frame SFNi+1+s,Where,

2 ms E-DCH TTI

For each cell in the E-DCH active set: The UE associates the E-DCH control information

received through subframe j of the E-HICH frame SFNi with subframe t of the E-DPDCHframe SFNi-s,

Where:

and .

For each cell that belongs to the serving E-DCH RLS: The UE first takes the E-DCH control

information received through subframe j of the E-RGCH frame SFNi into account in thehigher layer procedures that correspond to the E-DCH transmission in subframe j of theE-DPDCH frame SFNi+1.

For each cell that does not belong to the serving E-DCH RLS: The UE first takes the E-DCHcontrol information received through the E-RGCH frame SFNi into account in the higherlayer procedures that correspond to the E-DCH transmission in sub-frame t of the E-DPDCH

frame SFNi+1+s, where



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and

For the E-AGCH frame, UE first takes the E-DCH control information received throughsub-frame j of the E-AGCH frame SFNi into account in the higher layer procedures that

correspond to E-DCH transmission in sub-frame t of the E-DPDCH frame SFNi+s, where

and .

3.5 HSUPA Key Technologies

HSUPA Key Technologies describes the HSUPA key technologies: HARQ, short TTI, and fast

scheduling. With these key technologies, HSUPA provides a theoretical maximum uplinkMAC-e rate of 5.73 Mbit/s on the Uu interface, which increases the cell throughput.

3.5.1 HSUPA HARQ

Hybrid Automatic Repeat reQuest (HARQ) is a multi-instance Stop-And-Wait (SAW)

protocol. It is a combination of Forward Error Correction (FEC) and ARQ. For every HSUPAuser, an HARQ entity is present on both UE and NodeB sides, each having eight HARQ

processes in the case of 2 ms TTI or four HARQ processes in the case of 10 ms TTI. SeveralHARQ processes used together can fully use the transmission capability of the Uu interface.

HARQ Entity

In the UE, the HARQ entity is located in MAC-es/MAC-e. The HARQ entity can store the

MAC-e payloads and retransmit them. The RRC can configure the HARQ overMAC-controlled Service Access Point (SAP).

In the NodeB, the HARQ entity is located in MAC-e. Each process is responsible forgenerating ACKs or NACKs, which indicate the status of E-DCH transmissions.

The HARQ entity has the following parameters:

z E-TFC

z Retransmission Sequence Number (RSN)

z Power offset: used to calculate the power ratio of E-DPDCH to UL DPCCH

The E-TFC and the power offset are decided by HSUPA E-TFC Selection.

RSN (2-bit) is sent from the UE to the NodeB. If the number of transmissions is larger thanthree, the RSN is set to 3. The RSN can help to indicate the Redundancy Version (RV) of each

HARQ transmission and to assist in the NodeB soft buffer management.


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If more than three consecutive E-DPCCH transmissions in the HARQ process cannot bedecoded or the last received RSN is incompatible with the current one, the NodeB flushes thesoft buffer associated with the HARQ process to ensure that the soft buffer is in a good

condition.

Combining Modes of HARQ

HARQ supports two coding combining modes as shown in the following table. The

incremental redundancy mode is better because inconsistency between the retransmitted bitset and the former bit set leads to an increase in the redundant data and the possibility of

recovery from errors on the Uu interface.

Table 3-6Coding combining modes of HARQ

Coding Combining Mode Description

Chase combining mode In this mode, the same bit set is retransmitted.

Incremental redundancy mode In this mode, different bit sets are retransmitted.

Redundancy Version

Redundancy Version (RV) defines the selection of bits that can be transmitted on the air

interface resource, which is known as the rate matching pattern.

The RV can be derived by L1 from RSN and Connection Frame Number (CFN), or in the caseof 2 ms TTI from the subframe number.

The E-DCH RV index specifies the used RV. The UE uses the E-DCH RV indexes as listed inthe Table 3-7 .

Table 3-7Relationship between RSN values and E-DCH RV indexes

RSN Value E-DCH RV Index

(When Nsys/Ne,data,j < 1/2)

E-DCH RV Index

(When Nsys/Ne,data,j 1/2)

0 0 0

1 2 3

2 0 2

3 [ mod 2 ] x 2 mod 4

Note:

is to round down a value.

If configured by higher layers, only E-DCH RV index 0 can be used.

The parameters in the table are described as follows:

z Nsys is the number of system bits after channel coding.



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z Ne,data,j is the total number of bits available for the E-DCH transmission per TTI withtransport format j.

z TTIN is the TTI number.

For 10 ms TTI, TTIN = CFN.

For 2 ms TTI, TTIN = 5 x CFN + subframe number.

In this case, the subframe number counts the five TTIs within a given CFN, starting from 0

for the first TTI to 4 for the last TTI.

z NARQ is the number of HARQ processes.

3.5.2 HSUPA Short TTI

By using a short TTI on the Uu interface, HSUPA can implement faster data scheduling and

data transmission with lower delay. The 10 ms TTI is mandatory for R6 UE and the 2 ms TTIis optional for R6 UE.

RAN10.0 supports both 10 ms TTI and 2 ms TTI.

3.5.3 HSUPA Fast Scheduling

The MAC-e entity of the NodeB performs scheduling. The MAC-e entity uses the schedulinginformation contained in the enhanced uplink and the information carried by the E-DPCCH to

quickly adjust the rates of UEs based on the Uu resources. Thus, the fast scheduling helps

improve cell throughput.

For details about fast scheduling, see 4.2 HSUPA Fast Scheduling.

3.6 MAC-e PDU Generation

MAC-e PDU Generation describes the data transmission and MAC-e PDU generation on the

UE side.

3.6.1 MAC-e PDU Overview

MAC-e PDU Overview describes the overview of MAC-e PDU.


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Figure 3-14Simplified Architecture for MAC Inter-working in UE

In the figure, the left part shows the functional split, while the right part shows PDUarchitecture.

An RLC PDU enters MAC-d on a logical channel. The MAC-d C/T multiplexing is bypassed.

In the MAC-e header, the DDI (Data Description Indicator) field (6 bits) identifies logicalchannel, MAC-d flow and MAC-d PDU size. A mapping table is signaled over RRC, to allow

the UE to set DDI values. The N field (fixed size of 6 bits) indicates the number ofconsecutive MAC-d PDUs corresponding to the same DDI value. A special value of the DDI

field indicates that no more data is contained in the remaining part of the MAC-e PDU. TheTSN field (6 bits) provides the transmission sequence number on the E-DCH. The MAC-e

PDU is forwarded to a Hybrid ARQ entity, which then forwards the MAC-e PDU to layer 1

for transmission in one TTI.

3.6.2 MAC-e PDU Generation Process

On UE side, in each TTI, the UE performs Serving Grant (SG) update upon reception from

the downlink control command. Based on the SG, the UE selects the E-DCH TransportFormat Combination Indicator (E-TFCI) and finally creates the MAC-e PDU according to the

information on different logical channels in the buffer.

HSUPA Serving Grant Update

The Serving Grant (SG) update applies to every TTI boundary and takes into account the

Absolute Grant (AG), serving Relative Grant (RG), and non-serving RGs that apply to everyTTI.

The SG update procedure is shown in the Figure 3-15, and the AG processing procedure is

shown in Figure 3-16. Related terms and definitions are as follows:



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z AG_Timer and Non_serving_RG_timer: They are equal to one HARQ RTT (40 ms inthe case of 10 ms TTI, or 16 ms in the case of 2 ms TTI), as defined in 3GPP TS 25.321.

z Primary_Grant_Available: This state variable is a Boolean, indicating whether the UESG is affected only by Primary Absolute Grants and Relative Grants (that is, not by

Secondary Absolute Grants).z Primary Absolute Grant: An AG received with the primary E-RNTI.

z Secondary Absolute Grant: An AG received with the secondary E-RNTI.

z Serving E-DCH RLS or Serving RLS: A set of cells that contains at least the servingE-DCH cell and from which the UE can receive and combine one RG. The UE has onlyone serving E-DCH RLS.

z Identity Type: It takes the value "Primary" or "Secondary" based on whether the messageis addressed to the primary or the secondary E-RNTI.

z Stored_Secondary_Grant: This state variable is used to store the last received SecondaryAbsolute Grant value. The possible values are "Zero_Grant" and numerical values.


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Figure 3-15SG update procedure



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Figure 3-16AG processing procedure

According to the two procedures shown above, the SG update is described as follows:

z If any non-serving RGs indicate DOWN for a TTI, then

z The UE updates the SG and sets the Maximum_Serving_Grant to SG.

z The Non_Servig_RG_Timer is started (if it is inactive) and set to one HARQ RTT, and

z The AG or RG from the serving RLS at the same TTI is ignored.


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z If no non-serving RGs indicate DOWN for a TTI, the UE updates the SG according tothe AG or RG (used when no AG has been received and the AG_Timer has expired)received from the serving RLS. In addition, the new SG cannot exceed the

Maximum_Serving_Grant saved last time if the Non_Serving_RG_Timer has notexpired.

If the HSUPA UE receives more than one RG command, then one is from the serving RLS

and the others are from non-serving RLs. The RG commands from the serving RLS andnon-serving RLs are listed in the following table.

For detailed information on SG update, see subclause 11.8.1.3 in 3GPP 25.321.

Table 3-8RG commands

RG Commandfrom ServingRLS

RG Commandsfrom Non-ServingRLs

Final RG Command

UP All HOLD UP

The new SG, however, can not exceed theMaximum _Serving_Grant if theNon_Serving_RG_Timer has not expired.

UP At least one DOWN DOWN

The UE saves a new

Maximum_Serving_Grant. If theNon_Serving_RG_Timer is inactive, start it.

HOLD All HOLD HOLD

HOLD At least one DOWN DOWNThe UE saves a newMaximum_Serving_Grant. If theNon_Serving_RG_Timer is inactive, start it.

DOWN All HOLD DOWN

DOWN At least one DOWN DOWN

The UE saves a newMaximum_Serving_Grant. If theNon_Serving_RG_Timer is not active, start it.

HSUPA E-TFC Selection

At every TTI boundary, where a new transmission is required by the HARQ entity, the UEperforms the E-TFC selection procedure.

The RRC configures the MAC with a HARQ profile and a multiplexing list for each MAC-d

flow, as described below:

z The HARQ profile includes the power offset and the maximum number of HARQtransmissions.

z

The configuration of the HARQ profile is described in E-DCH Outer-Loop PowerControl.



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z The multiplexing list identifies the other MAC-d flows from which data can bemultiplexed for transmission that uses the power offset included in its HARQ profile.

z The principle of configuring the multiplexing list is that the MAC-d packet of lowerpriority logical channel can be multiplexed into the MAC-e PDU of the higher priority

logical channel, but the MAC-d packet of higher priority logical channel cannot bemultiplexed into the MAC-e PDU of the lower priority logical channel.

If the Scheduling Information (SI) needs to be transmitted without any higher-layer data, the

RRC configures the MAC with a special HARQ profile for "Control-only" transmissions:

z The power offset is fixed to 6dB.

z The maximum number of HARQ transmissions is eight in this case.

At each TTI boundary, the UE in CELL_DCH state with an E-DCH transport channel

determine the state of each E-TFC for each configured MAC-d flow based on its required

transmit power and the maximum UE transmit power. Note that:

z The calculation of the required transmit power for each E-TFC is the same as that

described in Power Control.

z For each configured MAC-d flow, a given E-TFC can be in Supported state or Blockedstate. Only E-TFCs in Supported state are considered in E-TFC selection.

z The SG update function provides the E-TFC selection function with the maximum

E-DPDCH to DPCCH power ratio that the UE is allowed to allocate for the upcomingtransmission for scheduled data.

If a 10 ms TTI is configured and the TTI for the upcoming transmission overlaps with a

compressed mode gap, the SG provided by the SG update function is scaled down accordingto the following equation:

SG' = SG x (NC/15)

Where:

z SG' represents the modified SG considered by the E-TFC selection algorithm.

z NC represents the number of non DTX slots in the compressed TTI.

Nc depends on the compressed mode which can be configured by the SET TGPSCP

command.

Through power offset and E-DCH Transport Format Combination (E-TFC) restriction

procedure, the TB size can be obtained in the next TTI.

For the detailed procedure of E-TFC selection, refer to the 25.321 protocol.

3.6.3 MAC-e PDU Encapsulation

The detailed procedure for encapsulating the MAC-e PDUs is described in Section 11.8.1.4

and Appendix C of 3GPP 25.321. According to the priority levels of logical channels and the

scheduling modes, the MAC-e PDUs can be encapsulated on the basis of the followingprinciples.

z The SI is always sent when the transmission is triggered.

z Logical channels support absolute priority, that is, the UE maximizes the transmissionamount of higher-priority data.

z For all logical channels:


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If the logical channel belongs to a non-scheduled MAC-d flow, the current non-scheduled

grant of the user determines whether the data can be transmitted.

If the logical channel does not belong to a non-scheduled MAC-d flow, the current SG of the

user determines whether the data can be transmitted.

The MAC-d flows are configured in non-scheduled transmission mode or scheduled

transmission mode.

Non-Scheduled Transmission Mode

In non-scheduled transmission mode, the UE can transmit data at the rate specified by the

RNC, without a grant from the Node B. The non-scheduled transmission mode is suitable for

the services with the requirements for low delay and steady source data rate.

In RAN10.0, only the streaming service, conversational service can be mapped onto the E-DCH innon-scheduled transmission mode.

If only non-scheduled MAC-d flows are configured for a UE, the NodeB does not send any

AG or RG to this UE. Therefore, in non-scheduled mode, the E-DCH becomes a "fastretransmission DCH" without scheduling.

If an MAC-d flow is configured with the non-scheduled transmission mode, the MAC-d

PDUs for logical channels belonging to this MAC-d flow shall not exceed the size specifiedby the IE "Max MAC-e PDU contents size".

The value of "Max MAC-e PDU contents size" is calculated in the RNC by the following

formula:

MaxMACePDUSize = [Ceil(MBR x TTILen / RLCPDUpayload) x MACdPDUSize + 18 ] xMaxRateUpScale

Where:

z MaxMACePDUSize: Max MAC-e PDU contents size

z Ceil(): to get the larger integer

z MBR: maximum bit rate specified by the Iu message RAB ASSIGNMENT REQUEST

z TTILen: TTI length

z RLCPDUpayload: RLC PDU payload, namely RLC PDU size minus RLC PDU header

z MACdPDUSize: MAC-d PDU size

z 18: sum of bits for the Transmission Sequence Number (TSN), Data DescriptionIndicator (DDI), and N (Number of MAC-d PDUs) fields

z MaxRateUpScale: used for multiplying the UL MBR in the RAB assignment to achievethe peak bit rate for the service bearers on the E-DCH The default value of

MaxRateScale is 1.01 for each RAB and 5 for each SRB.

Scheduled Transmission Mode

In scheduled transmission mode, the UE receives a grant from the NodeB before sending data.For detailed information, see 4.2 HSUPA Fast Scheduling.



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4-1

4 HSUPA AlgorithmsHSUPA algorithms introduce the HSUPA related algorithms, and proinformation on algorithms for fast scheduling, flow control, and CE

vide the detailedscheduling.

4.1 Overvi

orithms, namely, HSUPA fast

heduling algorithm. These algorithms

4.1.1 Algori

G), or relative grant (RG), the NodeB

performs fast scheduling to adjust the data rates of the UE. The scheduling procedure takes

o ,Iub fl onding

or

z he uplink throughput of a

z e same Scheduling Priority Indicator (SPI), theources to these UEs.

as a higher SPI, it can obtain more uplink resources

4.1.2 Algorithm of Flow Control

Flow control algorithm dynamically adjusts the available bandwidth of HSUPA UE based ontwork, the buffer usage, and variation trend of the Iub

y the fast scheduling algorithm grants the UE, thus

4.1.3 Algorithm of CE Allo

ew of HSUPA Related Algorithms

This section describes the relation among algorithms in HSUPA.

With the introduction of HSUPA, the NodeB uses three alg

scheduling algorithm, flow control algorithm, and CE screspectively consider the Uu resources, Iub resources, and CE resources on the NodeB.

thm of HSUPA Fast Scheduling

By sending a scheduling grant, absolute grant (A

int account such factors as Scheduling Priority Indicator (SPI), Guaranteed Bit Rate (GBR)ow control information, and CE resources for the UE, and uses the corresp

alg ithms to perform the following functions:

Efficient use of uplink resources: The algorithm maximizes tcell under the condition that the QoS requirements of all the UEs are met.

Fairness of services: If some UEs have thalgorithm allocates the same uplink res

z Differentiated services: If a user hcompared with a user with a lower SPI.

Flow control is implemented to reduce delay and packet loss rate, to maximize uplink

throughput, and to achieve better utilization of the Iub bandwidth.

the congestion state of the transport ne

port. This algorithm can also affect the wamatching the Uu rate with the Iub transport capability.

cation

After HSUPA is introduced, more CEs are required. As the number of HSUPA UEs increases,

the consumption of CEs also increases, and the CE resource may become a bottleneck.


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The CE scheduling algorithm dynamically adjusts theaccording to their data rates and preferentially serves t

CE resources allocated to the UEshe E-DCH RLS UE. It aims to reduce

4.1.4 Relation Among HSUPA Algorithms

ol the transmit data rate of the UE, theMAC-e entity. That is,

the probability of demodulation failure caused by CE resources, thus fully using the CE

resources.

Flow control and CE scheduling cannot directly contrresults of both flow control and CE scheduling shall be reported to the

the MAC-e scheduling controls the UE maximum data rate.

Figure 4-1Overview of HSUPA algorithms relation

The figure shows the relation among the three HSUPA algorithms on the NodeB side. TheHSUPA CE scheduler provides the MAC-e scheduler with the number of CEs allocated to the

UE and the maximum SG. The HSUPA flow control entity sends the available bandwidth ofto the MAC-e scheduler. In addition to the Uu resources,

rs the impact of flow control and CE scheduling results

4.2 HSUPA

4.2.1 Overview of HSUPA Scheduling

deB can control uplink interference. In this mode, the

b bandwidth, andr

avoid

e

z trol the maximumsed by the UE.

z Assigning the RG according to the Happy Bit.

HSUPA UE and the grant indicator

the MAC-e scheduling also conside

when giving the scheduling grants.

Fast Scheduling

In scheduled transmission mode, the NoUE sends resource requests with the Scheduling Information (SI) on the E-DPDCH and the

Happy Bit on the E-DPCCH, and the NodeB assigns a granted power ratio to the UE to

determine the UE rate.

Principle of the Scheduling Algorithm

The scheduling algorithm considers the UL load factor, available uplink IuCE esource. It uses the DL control channel (E-AGCH or E-RGCH) to affect the E-TFCIsused by the UEs. Thus, the algorithm can control the UL interference on the Uu interface and

congestion on the Iub interface.

Th scheduling algorithm mainly performs the following operations:

Assigning the AG based on the SI and Happy Bit sent by the UE to conrate that can be u



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z If the user is configured with the GBR by the RNC, and the GBR Schedule Switchparameter is set to TRUE (OPEN), the algorithm guarantees the GBR.

the conditions for sending RG UP are met, the algorithm assigns RG to the user.

Process of the Scheduling Algorithm

Whe

as foll

1. ch cell and the uplink Iub bandwidth for

l

h available for HSUPA users within the

2.

ailedResource Management

3.

d updates the UL load based on the current UL load. For detailed4.2.6 MBR Processing in the Scheduling Algorithm.

4.

ub

nhappy

heduling information, scheduling

6. d

Thefor t

7.

a.ilable

Scheduling Algorithm.

the Scheduling Algorithm.

For an unhappy user,

z

If the conditions for sending AG UP are met, the algorithm assigns AG to the user.z Else if

n the scheduling period (equal to one TTI) arrives, the scheduling algorithm functions are

ows:

Calculating the uplink Uu load resource of eaNodeB

Uplink Uu load resource of a cell = Maximum Target Uplink Load Factor - actuaload

Uplink Iub bandwidth of a NodeB = bandwidtNodeB range - total throughput of the users

Limiting the UE rates according to the CE resource

Based on SGmax and CE preemption, the algorithm sends AG DOWN. For detinformation on CE preemption and SGmax, see 4.4 Dynamic CE

Limiting the UE rates according to the MBR

The algorithm directly sends RG DOWN to the UEs whose rates need to be downsizedby MBR limitation aninformation, see

Limiting the UE rates according to the buffer congestion state

The algorithm sends RG DOWN to the user on the Iub port whose buffer is in acongested state. For details about how to judge the buffer status, see 4.3.4 Handling IBuffer Congestion.

5. Queuing users

The algorithm arranges all the users that are not granted within the NodeB based onHappy Bit, thus obtaining a sequence of happy queues and a sequence of u

queues. The factors to be considered include the scpriority indicator, GBR, and effective data rate.

Up ating the remaining resources

algorithm calculates the maximum resources that can be released by the happy usershe unhappy users, rather than sends RG DOWN to the happy users.

Scheduling the unhappy queues in a reverse order

If the conditions for sending AG UP are met, the algorithm assigns AG to the userbased on the available load resource of the cell where the UE camps or the ava

bandwidth of the Iub port where the UE is carried, and updates the remaining

resources. For details, see 4.2.3 AG UP Processing in the

b. If the conditions for sending RG UP are met, the algorithm assigns RG to the userbased on the available load resource of the cell where the UE camps or the availablebandwidth of the Iub port where the UE is carried, and updates the remaining

resources. For details, see 4.2.4 RG UP Processing in

8. Scheduling the happy queues and the unhappy queues in turn


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If the available load resource of the cell where the UE camps or the available bandwidtof the Iub port where the UE is carried

his smaller than zero, the algorithm sends RG

chedule Switch is ON and the value ofReffof an unhappy user is

smaller tha hedulinggo

The hafter sendi

z Experienced RTWP of the NodeB > target RTWP sent from the CRNC

4.2.2 User Queuing in the Scheduling Algorithm

Regardless of whether AG or RG is assigned, the users must be queued first. When the

to a happy sequence or ane e according to the happy bit carried on the E-DPCCH. During the queuing,

onsiders the SPI, GBR, and current effective data rate of each user.

Queuing Happ U

queu rder by Priorityn.

Prior

Whe

z

ing to the scheduling priority.

e the same as those used for HSDPA. For details, see QoSof Services Mapped on HSDPA.

reased before that of a user with a smaller Priorityn.

g to the formula described in Calculating the Effective Data

Queuing Unh

sers, the algorithm considers the effective data rate, SPI, and GBRon degree.

e

end o ulated by using the following formula:

DOWN to the UE and updates the remaining resources.

In the process, if the GBR S

n the GBR, the algorithm performs 4.2.5 GBR Processing in the ScAl rithm.

update is necessary to the remaining UL load source and remaining UL Iub bandwidtng the AG and RG to the UEs.

The NodeB does not send the non-serving RL RG DOWN command unless both of the

following criteria are met:

z Non-serving E-DCH to total E-DCH power ratio > Target Non-serving E-DCH toTotal E-DCH Power ratio sent from the CRNC

Target Non-serving E-DCH to Total E-DCH Power ratio can be set on the RNC LMT.

scheduling period arrives, and the NodeB receives the data or SI correctly, the schedulingalgorithm puts the users who can correctly receive data or SI inunhappy sequ nc

the algorithm also c

y sers

Regardless of whether the requirements of the users for the GBRs are met, the algorithmes all the happy users in descending o

ityn = Reff/SPI

re,

Priorityn is the priority value of user n

z SPI is assigned by the RNC, which is used to provide different scheduling opportunitiesaccord

SPI and SPI (SPI weight) arManagement

The smaller the SPI, the greater the value of Priorityn. During the scheduling, the rate of

such a user is dec

z Reffis calculated accordinRate.

appy Users

When queuing unhappy usatisfacti

Firstly, for zero_grant users,

Th algorithm arranges zero_grant users in descending order by Priorityn and puts them to the

f the unhappy sequence. Priorityn is calc



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Priorityn = 1/(SPI x Rreq)

Where,

n of user n.

g priority.

z re

Ra

Then, fo

z If t et to ON, the algorithm queues the users according to

l a by using the following formula:

f the user.

g order by Priorityn and puts them before the users whose requirements

SPI.

z If the GBR Schedule Switch is OFF, the users are queued according to the following

e al thm arranges them in descending order by Priorityn:

user is decreased before that of a following user but increased after that of a

Calculating th Ef

Reffi eceived data rate

f(n

If the data is received correctly, R(n, k) is equal to the total size of all the MAC-es PDUs

ooth factor and is fixed to 0.6%.

Calculating th

req

from TEBS in the UE buffer. The Rreq can not exceed the maximum data rate

f the power can not exceed the available power obtained from UEPow e H

z Priority is the priority value

z SPI is assigned by the RNC, which is used to provide different scheduling opportunitiesaccording to the schedulin

R q is calculated according to the formula described in Calculating the Requested Datate (Rreq).

r non-zero_grant users,

he GBR Schedule Switch is sthe following principles:

For the users whose requirements for the GBRs are not met, the algorithm arranges

them in descending order by Priorityn and puts them before the zero_grant users.Priorityn is ca cul ted

Priorityn = Reff/(SPIx RGBR)RGBRis the GBR o

For the users whose requirements for the GBRs are met, the algorithm arranges them

in descendinfor the GBRs are not met. Priorityn is calculated by using the following formula:

Priority = R /n eff

The rate of a user is decreased before that of a following user but increased after that ofthe following user.

principles:

For non-zero_grant users, th goriPriorityn = Reff/SPI

The rate of afollowing user.

e fective Data Rate (Reff)

s the effective data rate, which is a filtered value of the successfully r

with a -filter:

Ref ,k) = (1 - eff) x Reff(n, k - 1) + effx R(n, k)

z (n, k) means user n and TTI k.

z

(which are from the same MAC-e PDU) divided by the TTI length.

z Otherwise, R(n, k) is equal to zero. Reff(n, 1) is an initial value and is zero.

z effis an effective rate sm

e Requested Data Rate (Rreq)

The NodeB must determine the requested data rate (R ) based on the available data amount

obtained

con igured by the RNC ander H adroom (UP ).


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The form

Rreq(n,k) = R x user n and

TTI k.

1. lca.

b. (ed/c)2

for all E-TFCIs according to 3GPP.

1 or jth E-TFCI based on the TB table configured by the RNC.

rwise,

c.

/ )2

. From the TB table, select one E-TFCI whose

d. With the TTI attribute of the UE, the Rmax(UPH) is easy to obtain.

acts as the TB size divided by the TTI length for each E-TFC.

e maximum one andmeets the condition Q(k) R x TTI.

4.2.3 AG UP

cell of the UE receives the SI of the UE, the NodeB calculates therequested rate. For a user in the unhappy sequence, the algorithm determines whether to

er the AGCH code is idle, and whether the Iub bandwidth and CE resource are available.

the s the grant that can beUu bandwidth.

Conditions fo e

When

AG:

z Th

z Th ot used by other users.

z

SG ined from R req and Rcur.

ula for calculating Rreq is as follows:

min(Rmax , argmax{R|Q(k) TTI}, R(UPH) support), where (n,k) means

Ca ulate Rmax(UPH).Calculate ( / )ed c UPH

Assume that UPH = (

2according to UPH.

ed/c)2

UPH+ (ec/c)2

+ 1, where 1 stands for (c/c)2, the

power of DPCCH.

Because (ec/c)2

is known, (ed/c)2

UPH can be obtained from the equation.

Calculate all

-1 Get the TB size f

1-2 Calculate the quantized ed,j for jth E-TFCI using the method presented in HSUPAPower Control. Here,harq is the HARQ power offset of the MAC-d flow carryingthe logical channel with the ID of HLID.

1-3 j ++ ; If the value exceeds the range of the TB table, the process stops. Othereturn to 1-2.

Select Rmax(UPH).

The maximum (ed/c)2

is (ed c UPH(ed/c)

2is the most similar to but smaller than (ed/c)

2UPH. Then, the TB size can be

obtaine

2. Calculate R, which

Argmax{R|Q(K) R x TTI} means finding a value R that is th

Q(k) is the buffer size.

According to the buffer size and the TTI attribute of the UE, the R restricted by Q(k) isobtained.

3. Calculate Rsupport.

Rsupport= min{R (Maximum set of E-DPDCHs), R(E-DCH MBR)}

Processing in the Scheduling Algorithm

After the serving E-DCH

assign AG UP to the user based on whether a request for the SI is received from the UE,

wheth

If conditions for sending AG UP are met, the algorithm calculateassigned to the user based on the requested rate, Iub bandwidth, and

r S nding AG UP

the user meets all of the following conditions, the NodeB schedules this user through

e user is unhappy and the SI sent from the user is received.

e AGCH code allocated to the user is idle and n

The user meets the requirement: SGIndexreq - SGIndexcur> AG Threshold.

Indexreq and SGIndexcurare obta



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Rcuris the current bit rate of the UE, which is calculated on the basis of the E-TFCIcarried on the E-DPCCH.

Rcuris equal to the MAC-e PDU size divided by the TTI length. The MAC-e Psize can be obtained according to the

DUE-TFCI.

.2.2 User Queuing in the

ased because of MBR processing, Iub bandwidthitation.

ing algorithm calculates the AG to be

Dynamically Sthrough

Comperform of

lin

Dyna avoid the disadvantage described above.

z to 37 to

link load and a

B, the scheduler checks a Flag to decide the AG threshold:

G to this UE when

z

The sche

decid

z The initial value of the Flag is TRUE. The period is set to 500ms.

In the period, the Flag is set to FALSE when one of the following requirements is met:

r

If any TEBS in SI received in this period is greater than 20, which means 1658byte AG Threshold.

pared with RG, which increases or reduces the UE scheduling grant step by step, AG cana faster data rate. But if the AG threshold is too low, AG causes larger fluctuation

up k load due to a large UE data rate change.

mically setting AG threshold can

z When the traffic volume of a service source is small, the AG threshold is set to 3 so that

the user can get enough resource to send data out as soon as possible. It helps to improveuser experience with smaller latency.

When the traffic volume of a service source is large, the AG threshold is set

avoid usage of AG, and instead RG can be used to provide a steady cell upsteady throughput for each user.

When an SI is received by Node

z If the Flag is TRUE, the AG threshold is 3, the scheduler assigns ASGIndexreq - SGIndexcur> AG Threshold.

If the Flag is FALSE, AG threshold is 37 and only the RG can be used.

duler in NodeB maintains the Flag for each user periodically. The Flag can be

ed in the following ways:

z

If the total received data bit number is greater than 2 k bytes or the data rate is greatethan 4 k byte/sec, AG will not be used except at the beginning of transmission.

TEBS 2202byte.


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The SI is sent by the UE to the NodeB, as shown in the following figures.

Figure 4-2SI transmission

Figure 4-3SI structure

Whe

z

gical channels (for which the reporting has been requested by the RRC) ande

l channel identified by the HLID.

he triggering of a

When

z

G and the buffer status. If the SG has the

1D eventthis case, a new serving E-DCH cell is indicated in the message

and the new serving E-DCH cell is not in the previous serving E-DCH RLS.

re,

z UPH: UE Power Headroom, which indicates the ratio of the maximum UE transmission

power to the corresponding DPCCH code power.

TEBS: Total E-DCH Buffer Status, which identifies the total amount of data available

across all loindicates the amount of data in bytes available for transmission and retransmission at thRLC layer.

z HLBS: Highest priority Logical channel Buffer Status, which indicates the amount ofdata available from the logica

z HLID: Highest priority Logical channel ID, which identifies the highest-priority logicalchannel with available data.

The transmission of SI is initiated by the quantization of the transport block sizes that can be

supported, or by the triggering conditions. For details, see 3GPP25.321.

The reporting of SI is triggered according to the SG after SG is updated. T

report is indicated to the E-TFC selection function at the first new transmission. This processmay be delayed if the HARQ processes are occupied by retransmissions.

the TEBS is not zero, the SI transmission can be triggered by the following conditions:

Triggered by events

At each TTI boundary, the UE checks the S

value Zero_Grant or all processes are deactivated and the TEBS becomes greater thanzero, then the SI transmission is triggered.

If the serving E-DCH cell changes, the SI transmission is triggered. The change occurs,

for example, when the RNC sends a reconfiguration message in response to ameasurement report. In



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z

ured on the RNC LMT through the parameterHSUPA schedule

hd on the RNC LMT through the parameterHSUPA schedule period

RLSta

18

wever, no new SI is

MAC-e PDU.

4.2.4 RG UP

is ditions necessary for the algorithm to send the RG UP to the users.

z use of MBR processing, Iub bandwidth

bandwidth allow an

4.2.5 GBR Pr

d compare the effective data rate withet.

z from the CN carries the GBR when the

z onfigured on the RNC LMT is sent to the NodeB when the RAB is

ity (gold, silver, or copper) through theon the RNC LMT.

R

z

end AG UP or RG UP to those users whose requirements

z

stion threshold, the algorithm meets the

requirements of the users for the GBRs.

Triggered periodically

Triggered by the timer T_SIG (Timer Scheduling Information - not "Zero_Grant"),

which can be configperiod with grant.

Triggered by the timer T_SING (Timer Scheduling Information - "Zero_Grant"), whiccan be configurewithout grant.

If the HARQ process fails to deliver an MAC-e PDU that contains a triggered SI to thethat contains the serving cell, and the SI is transmitted together with higher-layer da

multiplexed into the same MAC-e PDU, the transmission of a new SI is triggered.

If the SI transmission is not triggered under the previous condition, but the size of the dataplus the header is smaller than or equal to the TB size of the UE-selected E-TFC minus

bits, the SI is concatenated into this MAC-e PDU. In this case, ho

triggered if the HARQ process fails to deliver the

For details of SI triggering, see 3GPP 25.321.

Processing in the Scheduling Algorithm

Th part describes the con

z The user is unhappy.

z The user does not meet the conditions for sending AG UP.

The rate of the user is not decreased becalimitation, and CE resource limitation.

z The user demodulates the data on the E-DPDCH correctly.

If all these conditions are met and both the Uu bandwidth and the Iubincrease in the user rate, the algorithm sends RG UP to the user.

ocessing in the Scheduling Algorithm

If a UE is configured with the GBR by the RNC and the GBR Schedule Switch parameter is

set to TRUE (OPEN), the scheduling algorithm shoulthe GBR and decide whether the GBR is m

GBR is transmitted from RNC to NodeB:

If the RAB ASSIGNMENT REQUEST message

RAB is set up, the GBR is sent to the NodeB.

Otherwise, the GBR ccarried on HSUPA.

The GBR can be configured for each user priorSET USERGBR command

GB processing is as follows:

If the load on the Uu interface exceeds the value ofMaximum Target Uplink LoadFactor, the algorithm does not sfor the GBRs are already met.

If the load on the Uu interface exceeds the value ofMaximum Target Uplink Load

Factor but does not exceed the load conge


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z If the load on the Uu interface exceeds the load congestion threshold, the algorithm doesnot meet the requirements of the users for the GBRs.

When the user meets the conditions for sending AG UP,

z

If Rreq is smaller than the GBR, only Rreq needs to be assigned to the user.z If Rreq is larger than the GBR,

If the estimated load does not exceed the load congestion threshold after the GBR isreached, at least the GBR is assigned to the user.

Otherwise, the algorithm calculates the maximum grant that can be assigned to theuser according to the load congestion threshold.

When the user does not meet the conditions for sending AG UP but meets the conditions for

sending RG UP,

z If the estimated load does not exceed the load congestion threshold after RG UP is sent,RG UP is sent to the user.

z Otherwise, RG UP is not sent to the user.

The load congestion threshold is 0.95. If the estimated load does not exceed the load

congestion threshold, neither the serving RLS nor the non-serving RL will send RG DOWN

to those users whose Reffis smaller than the GBR.

In addition, no matter whether the requirement for the GBR can be met, the grant assigned to

the user can not cause the throughput of the user to exceed the bandwidth available for the

HSUPA users in the NodeB.

4.2.6 MBR Processing in the Scheduling Algorithm

At each TTI, if both Rcurand Ravg of a user are greater than the E-DCH MBR, RG DOWN is

sent to this user.

The E-DCH MBR is transmitted by RNC to NodeB through the signaling. For detailedinformation, see 3GPP 25.433 9.2.2.13T.

Ravg is the average data rate of the UE, which is a smoothed value of Rcurwith an filter.

R (n, k) = (1 - ) x R (n, k - 1) + x R (n, k)avg avg avg avg cur

z (n, k) indicates user n and TTI k.

z avg is an Average Rate Smooth Factor, which is an coefficient.

z Ravg(n,1) is an Average Rate Initial Value, which is used at the beginning.

z Rcur(n, k) is the current bit rate of the UE, which is calculated on the basis of the E-TFCIcarried on the E-DPCCH.

Rcuris equal to the MAC-e PDU size divided by the TTI length. The MAC-e PDU size can beobtained according to the E-TFCI.

Average Rate Initial Value is set to 0 kbit/s and avg is set to 0.6%. Thus, the smoothing time is1.6s, about 10 times the period of fast fading that occurs during 3 km/h movement. Thepurpose is to reflect the impact of the channel fading and to smooth it.



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4.3 HSUPA Flow Control

4.3.1 Overview of HSUPA Flow Control

Flow control is implemented to reduce delay and packet loss rate, to maximize uplinkthroughput, and to achieve better use of the Iub bandwidth.

z The uplink throughput of a UE on the Uu interface may vary in a wide range. HSUPAUEs would share Iub resources in a more flexible way than R99 UEs.

z If the uplink throughput on the Uu interface is continuously wider than the Iub

bandwidth, the data stored in the Iub buffer will be continuously increased. Without flowcontrol, a higher delay or packet loss rate may be incurred.

z When the Iub bandwidth becomes the bottleneck of uplink data transmission, the delaymust be kept within the given range and packet loss must be minimized, thusmaximizing the uplink throughput and achieving better use of the Iub bandwidth.

Principles of Flow Control

The data rate on the Uu interface is restricted only by the UE capability and the grant given by

the MAC-e scheduler. Meanwhile, the flow control algorithm needs to maintain thethroughput from the Uu interface, which is the input throughput of the Iub interface under the

maximum rate allowed by the Iub bandwidth. Therefore, the flow control algorithm restrictsthe throughput on the Uu interface only by affecting the grant given by the scheduler.

Figure 4-4Principles of flow control

To control the packet loss and the delay on the Iub interface, the flow control algorithm

performs the following functions:

z Adjusts the maximum available bandwidth of Iub port according to the congestion stateof the transport network. This prevents large amounts of data from being discarded whendata convergence causes congestion in the transport network.

z Adjusts the available bandwidth of HSUPA according to the change trend of the Iubbuffer, and informs the scheduler of controlling the total traffic volume of HSUPA UEsaccording to their available bandwidth.

z Controls the Iub buffer usage to ensure that the buffer-caused delay is within the allowedrange without any packet loss.

The functional modules of the flow control algorithm are shown in the following figure.


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Figure 4-5Functional Modules of Flow Control Algorithm

z Scheduling Module: allocates grants to the UEs according to the Uu load resources andthe available bandwidth of the HSUPA users.

z Flow Control Module: adjusts the available bandwidth of every HSUPA user according

to the reported change trend of the buffer usage and the maximum available bandwidth,and provides the buffer congestion state of Iub port according to the buffer use.

z Transport Network Congestion Control Module: detects the congestion state of thetransport network and adjusts