HSUPA Description(2008!05!30)

RAN

HSUPA Description Issue 01

Date 2008-05-30

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RAN HSUPA Description Contents

Issue 01 (2008-05-30) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd

i

Contents

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

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

3 HSUPA Principles......................................................................................................................3-1 3.1 HSUPA Protocol Architecture .......................................................................................................................3-1 3.2 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

Contents RAN

HSUPA Description

ii Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd

Issue 01 (2008-05-30)

4.1.2 Algorithm of Flow Control ..................................................................................................................4-1 4.1.3 Algorithm of CE Allocation .................................................................................................................4-2 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........................................................................................................4-15

4.4 Dynamic CE Resource Management ..........................................................................................................4-16 4.5 Other HSUPA Related Algorithms ..............................................................................................................4-20

4.5.1 HSUPA Cell Load Control .................................................................................................................4-20 4.5.2 HSUPA DCCC ...................................................................................................................................4-20 4.5.3 HSUPA Power Control.......................................................................................................................4-21 4.5.4 HSUPA Mobility Management ..........................................................................................................4-21 4.5.5 HSUPA Directed Retry ......................................................................................................................4-22

5 HSUPA Reference Documents ................................................................................................5-1

RAN HSUPA Description 1 HSUPA Change History


1-1

1 HSUPA Change History

HSUPA Change History provides information on the changes between different document versions.

Document and s

T nt and p t versions

Product Version

able 1-1 Docume roduc

Document Version RAN Version RNC Version NodeB Version

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

n.

01 (2008-05-30This docum ercial release of

C d with draft (2008-03-20) of RAN10.0, issue 01 (2008-05-30) of RAN10.0 incorporates the changes described in the following table.

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

addition of information that was not provided in the previous versio

) is the

ompare

ent for the first comm RAN10.0.

Change Type

Change Description Parameter Change

Feature change

None. e no igurable are listed as follows:

Q Info for E-DCH HSUPA Scheduling Info power offset

The parameters that are changed to bn-conf

HAR

1 HSUPA Change History RAN

HSUPA Description

1-2 Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd

Issue 01 (2008-05-30)

Change Type


Editorial change

G

removed because of the creation of RAN10.0 parameter reference.

The structure is optimized.

None. eneral documentation change: The HSUPA Parameters is

Draft (2007-03This is a draft of the document for the first commercial release of RAN10.0.

C wit of RAN 6.1, this issue incorporates the chad d in the following table:

-20)

ompared escribe

h issue 03 (2008-01-20) nges

Change Type


SRB can be carried on E-DCH. None.

The algorithm of HSUPA scheduled transmission is changed. None.

The algorithm of HSUPA flow control is changed. None.

Feature change

None. The algorithm of HSUPA CE scheduling is introduced.

Editorial change

G entation information has been moved to a separate document. For detailed information on implementing HSUPA, refer to Configuring HSUPA in RAN Feature Configuration Guide.

None. eneral documentation change is as follows: Implem

RAN HSUPA Description 2 HSUPA Introduction


2-1

2 HSUPA Introduction

HSUPA (High Speed Uplink Packet Access) is an important feature of 3GPP R6. As an uplink SUPA provides a theoretical maximum uplink

AC uaw

The as follows:

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 handover

S) r with R99

o 6 ol

Iub flow control

Network Elements Involved The following table describes the Network Elements (NEs) involved in HSUPA.

(UL) high speed data transmission solution, HM -e rate of 5.73 Mbit/s on the Uu interface. The MAC-e peak data rate supported byH ei RAN10.0 is 5.73 Mbit/s.

main features of HSUPA are

2 ms short frame: It enables less Round Trip Time (RTT) in the Hybrid Automatic Repeat Request (HARQ) process, which is controlled by NodeB. It also shortens the scheduling response time. HARQ at threceived data packets between the User Equipment (UE) and NodeB.

NodeB-controlled UL fast scefficiency.

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

Higher UL peak data rate Lower latency: enhancing the subsc Faster UL resource co Better Quality of Service (QoS): imp UL peak rate: 5.73 Mbit/s per user 10 ms and 2 ms TTI Maximum 60 HSUPA users per Soft handover and sof Multiple RABs (3 P Dedicated/co-carrie UE categories 1 t Basic load contr OLPC for E-DCH

CE scheduling Power control of E-AGCH/E-RGCH/E-HICH

2 HSUPA Introduction RAN

HSUPA Description


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Table 2-1 NEs involved in HSUPA

UE NodeB RNC MSC Server MGW SGSN GGSN HLR

√ √ √ – – – – –

NOTE – = NE not involved √ = NE involved

UE = User Equipment, RNC = Radio Network Controller, MSC Server = Mobile Service Switching Center Server, MGW = Media Gateway, SGSN = Serving GPRS Support Node, GGSN = Gateway GPRS Support Node, HLR = Home Location Register

Impact Impact on System Performance

Compared with 3GPP R99, 3GPP R6 introduces HSUPA to provide a significant enhancement in the uplink in terms of peak data rate and cell throughput, a shorter latency, and a good balance between downlink and uplink.

Impact on Other Features The impact of HSUPA on the other features is as follows: − HSUPA does not affect the effectiveness of the other features. − 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.

RAN HSUPA Description 3 HSUPA Principles


3-1

3 HSUPA Principles

Th principles of HSUPA cover te he technical aspects of the feature:

HSUPA Physical Channel Timing HSUPA Key Technologies

3.1 HSUPArotocol architecture of HSUPA.

HSUPA Protocol Architecture HSUPA Channel Mapping HSUPA Physical Channels

MAC-e PDU Generation

Protocol Architecture HSUPA Protocol Architecture describes the p

Figure 3-1 shows the HSUPA protocol architecture.

Figure 3-1 Protocol 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

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.

3 HSUPA Principles RAN

HSUPA Description


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, ltiplexing.

added to SRNC to combine signals from different liver 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 SRNC MAC-es.

Step 4

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

ission, and switching.

3.2 HSUPA CU

3.2.1 Mappi service onto

scheme,

3.2.2 Mapping of Logical Channels onto Transport Channels Both Dedicated Control Channel (DCCH) and Dedicated Traffic Channel (DTCH) can be mapped onto the E-DCH in HSUPA.

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

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

A new transport channel (E-DCH) is added to transfer data blocks between NodeB MAC-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:

Mapping services information on the E-DCH, Mapping of logical channels onto the transport channels 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 thethe E-DCH according to the factors, such as, the traffic class, service rate, scheduling 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.



3-3

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

Figure 3-3 Mapping 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.


HSUPA Description


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Figure 3-4 Mapping of transport channels onto physical channels

3.3 HSUPA Physical Channels HSUPA Physical Channels describes five types of HSUPA physical channels:

E-DPCCH E-DPDCH E-AGCH E-RGCH E-HICH

3.3.1 E-DPCCH The E-DCH Dedicated Physical Control Channel (E-DPCCH) carries the control information associated with the E-DCH. Each radio link has at most one E-DPCCH. The spreading factor of the E-DPCCH is 256.



3-5

Figure 3-5 Frame structure of the E-DPCCH

The E-DPCCH carries the following control information:

Retransmission Sequence Number (RSN): 2 bits E-TFC Indicator (E-TFCI): 7 bits 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:

2 ms TTI E-DCH Transport Block Size Table 0 2 ms TTI E-DCH Transport Block Size Table 1 10 ms TTI E-DCH Transport Block Size Table 0 10 ms TTI E-DCH Transport Block Size Table 1

Table 0 or Table 1 is selected according to the signaling from the RNC and specified on the RNC LMT through the parameter E-TFCI Table Index. With the table, the E-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 indicate whether 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 set to Happy.


HSUPA Description


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

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

The UE has enough power to transmit data at a higher rate. 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) may require more than Happy bit delay time ms to be transmitted with the current SG multiplied by the ratio of the number of active processes to the total number of processes.

In this case, Happy bit delay time is configured by RRC. 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 factor of the E-DPDCH ranges from 2 to 256.

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

Figure 3-6 Frame 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.



3-7

Figure 3-7 Frame 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.

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

The AG scope indicates whether the HARQ process activation or deactivation will affect one 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 primary or a secondary E-RNTI. Here, the E-RNTI stands for E-DCH Radio Network Temporary Identifier.

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


HSUPA Description


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Table 3-1 Mapping 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



3-9

Absolute Grant Value Index

(7/15)2 2

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 3-8 Frame structure of the E-RGCH

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

If the cell transmitting the E-RGCH is in the serving E-DCH Radio Link Set (RLS), then 3 or 12 slots are used, depending on the E-DCH TTI is 2 ms or 10 ms.

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 3-2 Mapping of RG commands

RG Command

RG Value (for Serving E-DCH RLS)

RG Value (for Non-Serving E-DCH RL)

UP 1 Not allowed

HOLD 0 0

DOWN –1 –1


HSUPA Description


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When the UE receives an RG command, the SG is adjusted upwards or downwards by one step. The step can be 1, 2, or 3 in the Scheduling Grant Table according to the current SG value, E-RGCH 3-Index-Step Threshold, and E-RGCH 2-Index-Step Threshold. The Scheduling Grant Table is provided in Table 3-3.

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

The UE determines the lowest power ratio and the corresponding index in the Scheduling Grant Table: SGIndexLUPR. The lowest power ratio is in the Scheduling Grant Table (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 the amplitude ratios prior to the quantization according to 4.5.3 HSUPA Power Control.

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) as follows:

If SGIndexLUPR < 3-index-step threshold, then SG = SG [MIN (SG + 3, 37)]LUPR . For example, if SGIndexLUPR = 15 and 3-index-step threshold = 20, then the new SG

index is 18. If 3-index-step threshold ≤ SGIndexLUPR < 2-index-step threshold, then SG = SG [MIN

(SG + 2, 37)]LUPR . For example, if SGIndexLUPR = 21 and 2-index-step threshold = 25, then the new SG

index is 23. If SGLUPR ≥ 2-index-step threshold, then SG = SG [MIN (SG + 1, 37)]LUPR . For example, if the SGIndexLUPR = 28 and 2-index-step threshold = 25, then the new SG

index is 29. If the UE receives an RG "DOWN", then SG = SG[MAX (SG - 1, 0)]LUPR . SG = SG[SGIndex] which means to get an SG from the Scheduling Grant Table

according to the SGIndex.

Table 3-3 Scheduling 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



3-11

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


HSUPA Description


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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 a fixed 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 a sequence of 40 binary values is transmitted as follows:

3 slots are used for the UE with 2 ms E-DCH TTI. 12 slots are used for the UE with 10 ms E-DCH TTI.

Figure 3-9 Frame 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 3-4 Mapping of HARQ acknowledgement

Command HARQ Acknowledgement Indicator

ACK +1

NACK (for the RLSs not containing the serving E-DCH cell)

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.



3-13

Table 3-5 ACK/NACK combining

Transmission Data Type

ACK/NACK from Serving RLS

ACK/NACK from Non-Serving RLs

Operation of UE

All data ALL NACK ALL NACK The UE performs HARQ (re)transmissions until the maximum number of transmissions is reached.

All data At least one ACK

Either ACK or NACK

ACK

High-level data only

ALL NACK At least one ACK

ACK

Higher layer data and SI triggered by an event or timer

ALL NACK At least one ACK

The UE notifies the Scheduling Information Reporting function that the Scheduling Information is not received by the serving the RLS, flushes the packet, and includes the scheduling information with new data payload 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 the serving cell is received or until the maximum number of transmissions is reached.

3.4 HSUPA Physical Channel Timing The Primary Common Control Physical Channel (P-CCPCH), on which the cell System Frame 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 as that 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.


HSUPA Description


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Figure 3-10 E-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 3-11 E-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:

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

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

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



3-15

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

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

be chips.

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.


HSUPA Description


Issue 01 (2008-05-30)

Figure 3-13 E-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 layer procedures 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 information received 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-DPDCH frame 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 SFNiinto account in the higher layer procedures that correspond to the E-DCH transmission in subframe j of the E-DPDCH frame SFNi+1.

For each cell that does not belong to the serving E-DCH RLS: The UE first takes the E-DCH control information received through the E-RGCH frame SFNi into account in the higher layer procedures that correspond to the E-DCH transmission in sub-frame t of the E-DPDCH frame SFNi+1+s, where



3-17

and

For the E-AGCH frame, UE first takes the E-DCH control information received through sub-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 uplink MAC-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. Every HSUPA UE has an HARQ entity on both the UE and NodeB sides, each having eight HARQ processes in the case of 2 ms TTI and four HARQ processes in the case of 10 ms TTI. Several HARQ 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 over MAC-controlled Service Access Point (SAP).

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

The HARQ entity has the following parameters:

E-TFC Retransmission Sequence Number (RSN) 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 than three, the RSN is set to 3. The RSN can help to indicate the RV of each HARQ transmission and to assist in the NodeB soft buffer management.


HSUPA Description


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If more than three consecutive E-DPCCH transmissions in the HARQ process cannot be decoded or the last received RSN is incompatible with the current one, the NodeB flushes the soft 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 bit set 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 3-6 Coding 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 case of 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 in the Table 3-7 .

Table 3-7 Relationship 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:

Nsys is the number of system bits after channel coding.



3-19

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

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.

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 TTI is 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 scheduling information 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 3-14 Simplified Architecture for MAC Inter-working in UE

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

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 logical channel, 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 of consecutive 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. The TSN 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 Transport Format 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 every TTI.

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:



3-21

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

Primary_Grant_Available: This state variable is a Boolean, indicating whether the UE SG is affected only by Primary Absolute Grants and Relative Grants (that is, not by Secondary Absolute Grants).

Primary Absolute Grant: An AG received with the primary E-RNTI. Secondary Absolute Grant: An AG received with the secondary E-RNTI. Serving E-DCH RLS or Serving RLS: A set of cells that contains at least the serving

E-DCH cell and from which the UE can receive and combine one RG. The UE has only one serving E-DCH RLS.

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

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


HSUPA Description


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Figure 3-15 SG update procedure



3-23

Figure 3-16 AG processing procedure

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

If any non-serving RGs indicate DOWN for a TTI, then the UE updates the SG and sets the Maximum_Serving_Grant to SG. the Non_Servig_RG_Timer is started (if it is inactive) and set to one HARQ RTT, and


HSUPA Description


Issue 01 (2008-05-30)

the AG or RG from the serving RLS at the same TTI is ignored. If no non-serving RGs indicate DOWN for a TTI, the UE updates the SG according to

the 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 not expired.

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 and non-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 3-8 RG commands

RG Command from Serving RLS

RG Commands from Non-Serving RLs

Final RG Command

UP All HOLD UP The new SG, however, can not exceed the Maximum _Serving_Grant if the Non_Serving_RG_Timer has not expired.

UP At least one DOWN DOWN The UE saves a new Maximum_Serving_Grant. If the Non_Serving_RG_Timer is inactive, start it.

HOLD All HOLD HOLD

HOLD At least one DOWN DOWN The UE saves a new Maximum_Serving_Grant. If the Non_Serving_RG_Timer is inactive, start it.

DOWN All HOLD DOWN

DOWN At least one DOWN DOWN The UE saves a new Maximum_Serving_Grant. If the Non_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 UE performs 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:



3-25

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

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

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

The principle of configuring the multiplexing list is that the MAC-d packet of lower priority 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 be multiplexed 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:

The power offset is fixed to 6dB. 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:

The calculation of the required transmit power for each E-TFC is the same as that described in Power Control.

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

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 upcoming transmission 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 according to the following equation:

SG' = SG x (NC/15)

Where:

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

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 following principles.

The SI is always sent when the transmission is triggered.


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

For all logical channels:

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 in non-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 "fast retransmission 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 specified by 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 ] x MaxRateUpScale

Where:

MaxMACePDUSize: Max MAC-e PDU contents size Ceil(): to get the larger integer MBR: maximum bit rate specified by the Iu message RAB ASSIGNMENT REQUEST TTILen: TTI length RLCPDUpayload: RLC PDU payload, namely RLC PDU size minus RLC PDU header MACdPDUSize: MAC-d PDU size 18: sum of bits for the Transmission Sequence Number (TSN), Data Description

Indicator (DDI), and N (Number of MAC-d PDUs) fields MaxRateUpScale: used for multiplying the UL MBR in the RAB assignment to achieve

the peak bit rate for the service bearers on the E-DCH, which can be set on the RNC LMT through the parameter HSUPA service rate extend scale



3-27

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

RAN HSUPA Description 4 HSUPA Algorithms


4-1

4 HSUPA Algorithms

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

vide the detailed scheduling.

4.1 Overvi

orithms, namely, HSUPA fast heduling algorithm. These algorithms

4.1.1 AlgoriG), or relative grant (RG), the NodeB

performo ,

Iub fl nding or

e same Scheduling Priority Indicator (SPI), the ources 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 on twork, the buffer usage, and variation trend of the Iub

y the fast scheduling algorithm grants the UE, thus

ew of HSUPA Related Algorithms This section describes the relation among algorithms in HSUPA.

With the introduction of HSUPA, the NodeB uses three algscheduling 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

s fast scheduling to adjust the data rates of the UE. The scheduling procedure takes int account such factors as Scheduling Priority Indicator (SPI), Guaranteed Bit Rate (GBR)

ow control information, and CE resources of the UE, and uses the correspoalg ithms to perform the following functions:

Efficient use of uplink resources: The algorithm maximizes the uplink throughput of a cell 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

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

4 HSUPA Algorithms RAN

HSUPA Description


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4.1.3 Algoris the number of HSUPA UEs increases, ource may become a bottleneck.

es, thus fully using the CE resources.

4.1.4 Relatiota rate of the UE, the

MAC-e entity. That is,

thm of CE Allocation After HSUPA is introduced, more CEs are required. Athe consumption of CEs also increases, and the CE res

The CE scheduling algorithm dynamically adjusts the CE resources allocated to the UEs according to their data rates and preferentially serves the E-DCH RLS UE. It aims to reduce the probability of demodulation failure caused by CE resourc

n Among HSUPA Algorithms Flow control and CE scheduling cannot directly control the transmit daresults of both flow control and CE scheduling shall be reported to thethe MAC-e scheduling controls the UE maximum data rate.

Figure 4-1 Overview of HSUPA algorithms relation

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

PA flow control entity sends the available bandwidth of to the MAC-e scheduler. In addition to the Uu resources,

t of flow control and CE scheduling results

4.2 HSUPA4.2.1 Overview of HSUPA Scheduling

T e resou fect the E-TFCIs used by

rference on the Uu interface and avoid

HSUPA CE scheduler provides the MUE and the maximum SG. The HSUHSUPA UE and the grant indicator the MAC-e scheduling also considers the impacwhen giving the scheduling grants.

Fast Scheduling

In scheduled transmission mode, the NodeB can control uplink interference. In this mode, the UE 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

h scheduling algorithm considers the UL load factor, available Iub bandwidth, and CE rce. It uses the DL control channel (E-AGCH or E-RGCH) to af

the UEs. Thus, the algorithm can control the UL intecongestion on the Iub interface.



4-3

hm mainly performs the following operations:

imum

Assigning the RG according to the Happy Bit. the GBR by the RNC, and the GBR Schedule Switch PEN), the algorithm guarantees the GBR..

y user,

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

Process of the Scheduling Algorithm Whe

1. able

um Target Uplink Load Factor - actual

3. according to the MBR irectly sends RG DOWN to the UEs whose rates need to be downsized

4. Iub port whose buffer is in a

ow to judge the buffer status, see 4.3.4 Handling Iub

5. ed within the NodeB based on

peu

prio6. Upd

e s

7. Sche

a. UE camps or the available

The scheduling algorit

Assigning the AG based on the SI and Happy Bit sent by the UE to control the maxrate that can be used by the UE.

If the user is configured withparameter is set to TRUE (O

For an unhapp

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

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

Calculating the available Uu load resource of each cell and the Iub bandwidth availfor NodeB Available Uu load resource of a cell = Maximload Available Iub bandwidth of a NodeB = bandwidth available for HSUPA users within theNodeB range - total throughput of the users

2. Limiting the UE rates according to the CE resource Based on SGmax and CE preemption, the algorithm sends AG DOWN. For detailedinformation on CE preemption and SGmax, see 4.4 Dynamic CE Resource Management Limiting the UE rates The algorithm dby MBR limitation and updates the UL load based on the current UL load. For detailed information, see 4.2.6 MBR Processing in the Scheduling Algorithm. Limiting the UE rates according to the buffer congestion state The algorithm sends RG DOWN to the user on thecongested state. For details about hBuffer Congestion. Queuing users The algorithm arranges all the users that are not grantHa py Bit, thus obtaining a sequence of happy queues and a sequence of unhappy qu es. The factors to be considered include the scheduling information, scheduling

rity indicator, GBR, and effective data rate. ating the remaining resources

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

duling the unhappy queues in a reverse order

If the conditions for sending AG UP are met, the algorithm assigns AG to the user based on the available load resource of the cell where the 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 Scheduling Algorithm.


HSUPA Description


Issue 01 (2008-05-30)

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

unhappy queues in turn idth

updates the remaining resources.

In the pr er is al

Algo

h

d unless both of the

ent from the CRNC

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

4.2.2 User Qe queued first. When the

, the scheduling algorithm puts the users who can correctly receive ppy sequence or an unhappy sequence according to the happy bit carried

DPCCH. During the queuing, the algorithm also considers the SPI, GBR, and current effecti

Queuing Happ URegaqueu rityn.

Prior

yn is the priority value of user n ed by the RNC, which is used to provide different scheduling opportunities the scheduling priority.

reater the value of Priorityn. During the scheduling, the rate of efore that of a user with a smaller Priorityn.

b. If the conditions for sending RG UP are met, the algorithm assigns RG to the user based on the available load resource of the cell where the UE camps or the avabandresources. For details, see 4.2.4 RG UP Processing in the Scheduling Algorithm.

8. Scheduling the happy queues and theIf the available load resource of the cell where the UE camps or the available bandwof the Iub port where the UE is carried is smaller than zero, the algorithm sends RG DOWN to the UE and

ocess, if the GBR Schedule Switch is ON and the value of Reff of an unhappy ussm ler than the GBR, the algorithm performs 4.2.5 GBR Processing in the Scheduling

rithm.

The update is necessary to the UL load remaining load source and remaining Iub bandwidtafter sending the AG and RG to the UEs.

The NodeB does not send the non-serving RL RG DOWN commanfollowing criteria are met:

Experienced RTWP of the NodeB > target RTWP sent from the CRNC Non-serving E-DCH to total E-DCH power ratio > Target Non-serving E-DCH to

Total E-DCH Power ratio s

Target Non-serving

ueuing in the Scheduling Algorithm Regardless of whether AG or RG is assigned, the users must bscheduling period arrivesdata or SI into a haon the E-

ve data rate of each user.

y sers rdless of whether the requirements of the users for the GBRs are met, the algorithm es all the happy users in descending order by Prio

ityn = Reff/γSPI

Where,

Priorit SPI is assign

according to SPI and γSPI (SPI weight) are the same as those used for HSDPA. For details, see QoS Management of Services Mapped on HSDPA. The smaller the SPI, the gsuch a user is decreased b

Reff is calculated according to the formula described in Calculating the Effective Data Rate.



4-5

Queuing Unh pWhe SPIsatisfac

First ant users,

t users in descending order by Priorityn and puts them to the end of t

Prior

Where,

Pri SP ich is used to provide different scheduling opportunities

acc in ity. e

a

Then, fo

calculated by using the following formula:

of the user.

order by Priorityn and puts them before the users whose requirements for the GBRs are not met. Priorityn is calculated by using the following formula:

ers are queued according to the following

lgorithm arranges them in descending order by Priorityn:

ased after that of a

Calculating the Effective Data Rate (Reff) ltered value of the successfully received data rate

TTI k. qual to the total size of all the MAC-es PDUs

ed by the TTI length.

ap y Users n queuing unhappy users, the algorithm considers the effective data rate, γ , and GBR

tion degree.

ly, for zero_gr

The algorithm arranges zero_granhe unhappy sequence. Priorityn is calculated by using the following formula:

ityn = 1/(γSPI x Rreq)

orityn is the priority value of user n. I is assigned by the RNC, whord g to the scheduling prior

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

r non-zero_grant users,

If the GBR Schedule Switch is set to ON, the algorithm queues the users according to the 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 isPriorityn = Reff/(γSPI x RGBR)RGBR is the GBR

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

Priorityn = Reff/γSPI. The rate of a user is decreased before that of a following user but increased after that ofthe following user.

If the GBR Schedule Switch is OFF, the usprinciples: For non-zero_grant users, the aPriorityn = Reff/γSPI

The rate of a user is decreased before that of a following user but increfollowing user.

Reff is the effective data rate, which is a fiwith a α-filter:

Reff(n,k) = (1 - αeff) x Reff(n, k - 1) + αeff x R(n, k)

(n, k) means user n and If the data is received correctly, R(n, k) is e

(which are from the same MAC-e PDU) divid


HSUPA Description


Issue 01 (2008-05-30)

f is an effective rate smooth factor and is fixed to 0.6%.

Calculating the RequThe Nod unt obtained E buffer. The Rreq can not exceed the maximum data rate configur c t e rom UE Power H

The form

Rreq(n,k)TTI k.

1. Ca

a.

A (ßed/ßc)2UPH + (ßec/ßc)2 + 1, where 1 stands for (ßc/ßc)2, the

p

b.

Q power offset of the MAC-d flow carrying

the ID of HLID.

PH).

t one E-TFCI whose (ß /ß ) is the most similar to but smaller than (ß /ß ) . Then, the TB size can be

y to obtain. 2. Calculate R, which acts as the TB size divided by the TTI length for each E-TFC.

3. Calculate R . ximum set of E-DPDCHs), R(E-DCH MBR)}

4.2.3 AG UPte e NodeB calculates the

ether to assign UE,

et are available. If the ates the grant that can be assigned to the user based on the requested rate, Iub bandwidth, and Uu bandwidth.

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

ested Data Rate (Rreq) eB must determine the requested data rate (Rreq) based on the available data amo from TEBS in the Ued by the RNC and the power an no xceed the available power obtained feadroom (UPH).

ula for calculating R is as follows: req

= min(Rmax(UPH), argmax{R|Q(k) ≥ R x TTI}, Rsupport), where (n,k) means user n and

lculate Rmax(UPH).

Calculate (ßed/ßc)2UPH according to UPH.

ssume that UPH = ower of DPCCH.

Because (ßec/ßc)2 is known, (ßed/ßc)2UPH can be obtained from the equation.

Calculate all (ßed/ßc)2 for all E-TFCIs according to 3GPP.

1-1 Get the TB size for jth E-TFCI based on the TB table configured by the RNC. 1-2 Calculate the quantized ßed,j for jth E-TFCI using the method presented in HSUPAPower Control. Here, Δharq is the HARthe logical channel with1-3 j ++ ; If the value exceeds the range of the TB table, the process stops. Otherwise, return to 1-2.

c. Select Rmax(U

The maximum (ßed/ßc)2 is (ßed/ßc)2UPH. From the TB table, selec

2 2ed c ed c UPH

obtained. With the TTI attribute of the UE, the Rmax(UPH) is eas

− Argmax{R|Q(K) ≥ R x TTI} means finding a value R that is the maximum one and meets the condition Q(k) ≥ R x TTI.

− 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.

support

Rsupport = min{R (Ma

Processing in the Scheduling Algorithm Af r the serving E-DCH cell of the UE receives the SI of the UE, threquested rate. For a user in the unhappy sequence, the algorithm determines wh

AG UP to the user based on whether a request for the SI is received from the wh her the AGCH code is idle, and whether the Iub bandwidth and CE resource

conditions for sending AG UP are met, the algorithm calcul



4-7

Conditions for SeWhen th AG:

Th o the user is idle and not used by other users.

FCI

cur length. The MAC-e PDU

Queuing in the Scheduling Algorithm.

namically according to the traffic volume at the service

ling algorithm calculates the AG to be

Dynamically S tiWhe est, the NodeB can schedule the user through

Comperfo threshold is too low, AG causes larger fluctuation of

na

all, the AG threshold is set to 3 so that helps to improve

o ead RG can be used to provide a steady cell uplink load and a

tSG

t

The scheduler in NodeB maintains the Flag for each user periodically. The Flag can be ded in the following ways:

of the following requirements is met:

nding AG UP e user meets all of the following conditions, the NodeB schedules this user through

The user is unhappy and the SI sent from the user is received. e AGCH code allocated t

The user meets the requirement: SGIndexreq - SGIndexcur > AG Threshold. SGIndexreq and SGIndexcur are obtained from Rreq and Rcur. − Rcur is the current bit rate of the UE, which is calculated on the basis of the E-T

carried on the E-DPCCH. R is equal to the MAC-e PDU size divided by the TTI size can be obtained according to the E-TFCI.

− Rreq is calculated according to the formula described in 4.2.2 User

The AG threshold is adjusted dysource. For details, see Dynamically Setting the AG Threshold.

The rate of the user is not decreased because of MBR processing, Iub bandwidth limitation, and CE resource limitation.

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

If the user meets all these conditions, the scheduassigned to the user based on the Uu bandwidth and Iub bandwidth.

et ng the AG Threshold n a non-zero_grant user sends an SI requ

AG if SGIndexreq - SGIndexcur > AG Threshold.

pared with RG, which increases or reduces the UE scheduling grant step by step, AG can rm a faster data rate. But if the AG

uplink load due to a large UE data rate change.

Dy mically setting AG threshold can avoid the disadvantage described above.

When the traffic volume of a service source is smthe user can get enough resource to send data out as soon as possible. It user experience with smaller latency.

When the traffic volume of a service source is large, the AG threshold is set to 37 tavoid usage of AG, and inststeady throughput for each user.

When an SI is received by NodeB, the scheduler checks a Flag to decide the AG threshold:

If he Flag is TRUE, the AG threshold is 3, the scheduler assigns AG to this UE when Indexreq - SGIndexcur > AG Threshold.

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

deci

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


HSUPA Description


Issue 01 (2008-05-30)

data rate is greater than 4 k byte/sec, AG will not be used except at the beginning of transmission.

received in this period is greater than 20, which means 1658byte < TEBS ≤ 2202byte.

SI Transmission to notify the serving NodeB of

owing figures.

− If the total received data bit number is greater than 2 k bytes or the

− If any TEBS in SI

The SI is attached to the end of the MAC-e PDU and is used the amount of system resources required by the UE.

The SI is sent by the UE to the NodeB, as shown in the foll

Figure 4-2 SI transmission

Figure 4-3 SI structure

he

which indicates the ratio of the maximum UE transmission

t of data available across all logical channels (for which the reporting has been requested by the RRC) and

the amount of

ty Logical channel ID, which identifies the highest-priority logical e data.

The supp tails, see 3GPP25.321.

The repomay be delayed if the HARQ processes are occupied by retransmissions.

W re,

UPH: UE Power Headroom, power to the corresponding DPCCH code power.

TEBS: Total E-DCH Buffer Status, which identifies the total amoun

indicates the amount of data in bytes available for transmission and retransmission at theRLC layer.

HLBS: Highest priority Logical channel Buffer Status, which indicates data available from the logical channel identified by the HLID.

HLID: Highest priorichannel with availabl

transmission of SI is initiated by the quantization of the transport block sizes that can beorted, or by the triggering conditions. For de

reporting of SI is triggered according to the SG after SG is updated. The triggering of a rt is indicated to the E-TFC selection function at the first new transmission. This process



4-9

Whe

e ing E-DCH cell is not in the previous serving E-DCH RLS.

, edule

h iod

PDU that contains a triggered SI to the RLS that contains the serving cell, and the SI is transmitted together with higher-layer data

gered.

s, into this MAC-e PDU. In this case, however, no new SI is gg

4.2.4 RG UP hm rs.

The rate of the user is not decreased because of MBR idth

Uu bandwidth and the Iub bandwidth allow an s RG UP to the user.

4.2.5 GBR Proc gorithm If a Uset tothe G

deB:

n 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 SG and the buffer status. If the SG has the value Zero_Grant or all processes are deactivated and the TEBS becomes greater than zero, 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 a 1D event measurement report. In this case, a new serving E-DCH cell is indicated in the messagand the new serv

Triggered periodically Triggered by the timer T_SIG (Timer Scheduling Information - not "Zero_Grant")which can be configured on the RNC LMT through the parameter HSUPA schperiod with grantTriggered by the timer T_SING (Timer Scheduling Information - "Zero_Grant"), whiccan be configured on the RNC LMT through the parameter HSUPA schedule perwithout grant.

If the HARQ process fails to deliver an MAC-e

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

If the SI transmission is not triggered under the previous condition, but the size of the data plus the header is smaller than or equal to the TB size of the UE-selected E-TFC minus 18 bit the SI is concatenatedtri ered if the HARQ process fails to deliver the MAC-e PDU.

For details of SI triggering, see 3GPP 25.321.

Processing in the Scheduling AlgoritThis part describes the conditions necessary for the algorithm to send the RG UP to the use

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

processing, Iub bandwlimitation, and CE resource limitation.

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

If all these conditions are met and both theincrease in the user rate, the algorithm send

essing in the Scheduling AlE is configured with the GBR by the RNC and the GBR Schedule Switch parameter is TRUE (OPEN), the scheduling algorithm should compare the effective data rate with BR and decide whether the GBR is met.

GBR is transmitted from RNC to No

If the RAB ASSIGNMENT REQUEST message from the CN carries the GBR when theRAB is set up, the GBR is sent to the NodeB. Otherwise, the GBR configured on the RNC LMT is sent to the NodeB when the RAB is carried on HSUPA.


HSUPA Description


Issue 01 (2008-05-30)

GBR pro

ximum Target Uplink Load P to those users whose requirements

ink Load load congestion threshold, the algorithm meets the

tnot

When th

r than the GBR,

is assigned to the user. aximum grant that can be assigned to the

sent to the user.

xceed the load will send RG DOWN

tter whether the requirement for the GBR can be met, the grant assigned to e

4.2.6 MBR Pcur avg than the E-DCH MBR, RG DOWN is

t

. For detailed

.

e basis of the E-TFCI carried on the E-DPCCH.

The GBR can be configured for each user priority (gold, silver, or copper) through the SET USERGBR command on the RNC LMT.

cessing is as follows:

If the load on the Uu interface exceeds the value of MaFactor, the algorithm does not send AG UP or RG Ufor the GBRs are already met.

If the load on the Uu interface exceeds the value of Maximum Target UplFactor but does not exceed therequirements of the users for the GBRs. If he load on the Uu interface exceeds the load congestion threshold, the algorithm does

meet the requirements of the users for the GBRs.

e user meets the conditions for sending AG UP,

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

− If the estimated load does not exceed the load congestion threshold after the GBR is reached, at least the GBR

− Otherwise, the algorithm calculates the muser 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,

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

Otherwise, RG UP is not

The load congestion threshold is 0.95. If the estimated load does not econgestion threshold, neither the serving RLS nor the non-serving RLto those users whose Reff is smaller than the GBR.

In addition, no mathe user can not cause the throughput of the user to exceed the bandwidth available for thHSUPA users in the NodeB.

rocessing in the Scheduling Algorithm At each TTI, if both R and R of a user are greater sen to this user.

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

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

Ravg(n, k) = (1 - αavg) x Ravg(n, k - 1) + αavg x Rcur(n, k)

(n, k) indicates user n and TTI k αavg is an Average Rate Smooth Factor, which is an α coefficient. Ravg(n,–1) is an Average Rate Initial Value, which is used at the beginning. Rcur(n, k) is the current bit rate of the UE, which is calculated on th



4-11

U size divided by the TTI length. The MAC-e PDU size can be CI.

avg is set to 0.6%. Thus, the smoothing time occurs during 3 km/h movement. The

4.3 HSUPA F4.3.1 Overview

wthrou

PA n a more flexible way than R99 UEs.

hroughput on the Uu interface is continuously wider than the Iub

Principles of Ft given by

rface under the restricts

Rcur is equal to the MAC-e PDobtained according to the E-TF

Average Rate Initial Value is set to 0 kbit/s and αis 1.6s, about 10 times the period of fast fading that purpose is to reflect the impact of the channel fading and to smooth it.

low Control of HSUPA Flow Control

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

The uplink throughput of a UE on the Uu interface may vary in a wide range. HSUUEs would share Iub resources i

If the uplink tbandwidth, the data stored in the Iub buffer will be continuously increased. Without flow control, a higher delay or packet loss rate may be incurred.

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

low Control The data rate on the Uu interface is restricted only by the UE capability and the granthe MAC-e scheduler. Meanwhile, the flow control algorithm needs to maintain the throughput from the Uu interface, which is the input throughput of the Iub intemaximum rate allowed by the Iub bandwidth. Therefore, the flow control algorithmthe throughput on the Uu interface only by affecting the grant given by the scheduler.

Figure 4-4 Principles of flow control

To c e Iub interface, the flow control algorithm

ontrol the packet loss and the delay on thperforms the following functions:


HSUPA Description


Issue 01 (2008-05-30)

ate of the transport network. This prevents large amounts of data from being discarded when

etwork. Adjusts the available bandwidth of HSUPA according to the change trend of the Iub

Es

lowed

Adjusts the maximum available bandwidth of Iub port according to the congestion st

data convergence causes congestion in the transport n

buffer, and informs the scheduler of controlling the total traffic volume of HSUPA Uaccording to their available bandwidth.

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

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

Figure 4-5 Functional Modules of Flow Control Algorithm

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

Flow Control Module: adjusts the available bandwidth of every HSUPA user according he maximum available bandwidth,

Iub port according to the buffer use. Transport Network Congestion Control Module: detects the congestion state of the

ngly. Buffer Usage Reporting Module: reports the buffer use of Iub port.

um Available Bandwidth of the Iub Port

djusts the maximum available bandwidth of the Iub port

to the reported change trend of the buffer usage and tand provides the buffer congestion state of

transport network and adjusts the maximum available bandwidth of Iub port accordi

The detailed functions of each module are described in the following sections.

4.3.2 Adjusting the Maximum Available Bandwidth of the Iub Port 4.3.3 Adjusting the Available Bandwidth of HSUPA 4.3.4 Handling Iub Buffer Congestion

4.3.2 Adjusting the Maxim

In the case of network convergence or hub NodeB, the bandwidth configured for the NodeB can be greatly wider than the resource available in the transport network. The HSUPA flow control algorithm automatically a



4-13

. ATM transport is different from IP transport; therefore, two different algorithms are provided.

ng the to notify the

terface, as

based on the congestion state of the transport network

Algorithm for ATM Transport The RNC side detects the delay and loss of the FP frame in each MAC-d flow by usiFSN and CFN in the FP frame. Then, the RNC side sends a congestion indication NodeB of the congestion state when the MAC-d flow is transmitted on the Iub inshown in the following figure.

Figure 4-6 Procedure of TNL congestion indication

us indicates whether there is transport network congestion. Its ue

stion – detected by delay build-up T

When th odeB takes statis sthe follo

If tNo the th. This step is set to 2%.

congestion indication "TNL Congestion – detected by delay build-up", et

received during three consecutive periods nor the

s.

Where the Congestion Statval range is described as follows:

0: no TNL congestion 1: reserved for future use 2: TNL Conge3: NL Congestion – detected by frame loss

e period for adjusting the maximum available bandwidth arrives, the Ntic on the congestion indications of all the MAC-d flows on the Iub port and performs

wing operations:

here is a congestion indication "TNL Congestion – detected by frame loss", the deB subtracts the product of the maximum available bandwidth and a preset step from maximum available bandwid

Otherwise, − If there is a

the NodeB subtracts the product of the maximum available bandwidth and a presstep from the maximum available bandwidth. This step is set to 1%.

− If neither congestion indication isuse of the Iub bandwidth exceeds a preset value which equals to 85%, the NodeB increases the maximum available bandwidth by one step. The initial step is 10 kbit/


HSUPA Description


Issue 01 (2008-05-30)

Algorithm for IP Transport For Irather thdelay an network.

After knoperatio

t of the maximum andwidth. This step

bandwidth by one step. The initial step is 10 kbit/s.

4.3.3 Adjustther than the transport

network, the maximum available bandwidth of the Iub port is just equal to the bandwidth e Iub port bandwidth is adjusted by 4.3.2 Adjusting

M ork, b

intro s an in

The excecapa l the w erefore, through the variation trend of the occupancy rate of the buffer, the NodeB can learn how to adjust the available bandwidth of HSUPA.

is 150

% in the buffer non-congestion state, the of HSUPA users based on the variation. The riation. The adjustment upper limit is 150

The adjustment must guarantee that the available bandwidth of HSUPA users cannot exceed

When a lot of R99 users access the network in a short period of time, the occupancy rate of the Iub buffer jumps and even the buffer may overflow. To avoid this problem, the

The step is doubled every time the five consecutive increases are complete. The maximum step is 100 kbit/s.

P transport, the NodeB side directly uses the Performance Monitor (PM) algorithm, an the congestion indication from the RNC, to periodically detect the transmission d frame loss in the IP

owing the congestion state of the Iub interface, the NodeB performs the following ns:

If the congestion is due to frame loss, the NodeB subtracts the producavailable bandwidth and a preset step from the maximum available bis set to 2%.

Otherwise, − If the congestion is due to delay, the NodeB subtracts the product of the maximum

available bandwidth and a preset step from the maximum available bandwidth. This step is set to 1%.

− If neither congestion is detected during three consecutive periods nor the NodeB increases the maximum availableThe step is doubled every time the five consecutive increases are complete.

ing the Available Bandwidth of HSUPA If the transmission bottleneck of the Iub interface lies in the NodeB ra

configured for the NodeB. Otherwise ththe aximum Available Bandwidth of the Iub Port. When R99 users enter or exit the netwthe andwidth available for HSUPA users changes accordingly. Therefore, a scheme is

duced to estimate the bandwidth available for HSUPA users. This bandwidth is taken aput of the scheduling algorithm.

data is buffered on the NodeB side when the traffic on the Uu interface jumps and eds the capacity of the Iub interface. If the traffic on the Uu interface exceeds the city of the Iub interface all the while, the occupancy rate of the buffer also increases alhile. Th

The adjustment process is as follows:

If the occupancy ratio of the Iub buffer increases, the NodeB reduces the available bandwidth of HSUPA users based on the variation. The adjustment upper limitkbit/s. The adjustment is in direct proportion to the variation.

If the occupancy ratio of the Iub buffer decreases and the use of the Iub bandwidth exceeds a preset value, which equals to 85NodeB increases the available bandwidth adjustment is in direct proportion to the vakbit/s.

the maximum available bandwidth.



4-15

ow control algorithm based on the occupancy rate of the buffer. For detailed information, see 4.3.4 Handling Iub Buffer Congestion.

4.3.4 Handlin

igure 4-7 Handling Iub buffer congestion

backpressure mechanism is introduced to the fl

g Iub Buffer Congestion The HSUPA flow control algorithm detects the status of the Iub buffer periodically and handles Iub buffer congestion to minimize Iub packet loss rate and delay in the Iub buffer.

The following figure shows the procedure for handling Iub buffer congestion.

F

The measures and stores the value of the Iub buffer occupancy rate

The of the buffer state is as follows:

t Used Ratio T r state is

hWh

− ffer Used Ratio is 5%.

e

If the Iub buffer is congested, the NodeB compares the value of the Iub buffer occupancy rate with the previous one every 40 ms. .

eduler sends the RG Down message is allowed to be sent to these

users. ncrease, neither AG Up nor RG Up is

n

Iub flow control moduleevery 40 ms and compares it with the previous one.

detection

If he Iub buffer occupancy rate > The Congestion Threshold of IUB Buffer+ he Congestion Threshold Hysteresis of IUB Buffer Used Ratio, the buffemarked congested.

If the Iub buffer occupancy rate < The Congestion Threshold of IUB Buffer Used Ratio - The Congestion Threshold Hysteresis of IUB Buffer Used Ratio, the buffer state is marked not congested. Ot erwise, the buffer status remains unchanged.

ere, − The Congestion Threshold of IUB Buffer Used Ratio is 30%,

The Congestion Threshold Hysteresis of IUB Bu

Th processing after congestion detection is as follows:

− If the Iub buffer occupancy rate increases, the schto all the HSUPA users on this Iub port, and no AG

− If the Iub buffer occupancy rate does not iallowed to be sent to the users on this Iub port.

If the Iub buffer is not congested, the flow control algorithm does not affect the decisioof the scheduler.


HSUPA Description


Issue 01 (2008-05-30)

4.4 Dynam

Overview of D E Resource Management

res the CE

pacity, but HSUPA consumes large CE resources.

he NodeB will allocate the CE resources me is very low. In this

c CE resource management

cally adjusts CE .

decoding due to CE.

ic CE Resource Management

ynamic CA channel element (CE) is defined as the baseband resources required in the NodeB to provide capacity for 12.2 k AMR voice, including 3.4 k DCCH. The HSUPA sharesource with the R99 services.

The HUSPA improves the uplink performance of delays and rates ca

If there is no dynamic CE resource management, taccording to the maximum rate of the UE, even if the actual traffic volucase, the utility of the CE resource is inefficient. Thus, the dynamiis necessary.

Considering that the rate of HSUPA user changes fast, the algorithm periodiresources of users according to the users’ rate and the available CE resources

Dynamic CE management can minimize the failures in demodulation andMeanwhile, it also can maximize the CE usage and UL throughput.

Figure 4-8 Overview of CE resource management

MAC-e scheduler always takes the CE resources allocated to the user into consideration.

CE resource adjustment is performed periodically or triggered by events.



4-17

Periodical CE Resource Adjustment The procedure for periodical CE resource adjustment is shown in the following figure.

Figure 4-9 Procedure for periodical CE resource adjustment

When each adjustment period arrives, the algorithm performs the following operations:

1. Call back the CE resources of the serving RLS

The NodeB determines whether to call back the CEs based on the CEavg during the previous period.

If the CEallocate is greater than both CEinit and CEavg, the NodeB calls back some CEs and decreases CEallocate to Max(CEavg,CEinit). The CE resources called back takes effect during the next period. The algorithm notifies the SGmax to the MAC-e scheduler at current TTI.

CEallocate: The number of CEs allocated to the serving RLS. CEinit: Initial number of CEs, which is calculated on the basis of the configured GBR. If

the user is not configured with the GBR, then CEinit is the CE resources for transmitting an RLC PDU.

CEavg: Average number of CEs, which is calculated on the basis of the average rate of the serving RLS.

SGmax: Maximum SG for the UEs, which is determined by the function of the dynamic CE resource management. Since one SG may correspond to different CE numbers, if MAC-e scheduler uses this SG, the allocated CE resources may be insufficient. Therefore,


HSUPA Description


Issue 01 (2008-05-30)

the algorithm needs to notify the MAC-e scheduler of the SGmax to avoid CE insufficiency.

2. Processing CE resources among serving RLS for fairness

If the available CE resources for serving RLS are less than the CE resources that are required for increasing the SF4 to 2xSF4, the algorithm performs fairness processing.

Table 4-1 HSUPA CEs consumption rules

MinSF HSUPA phase 1 HSUPA phase 2

SF64 1+1+1 1

SF32 1+1+1.5 1.5

SF16 1+1+3 3

SF8 1+1+5 5

SF4 1+1+10 10

2xSF4 1+1+20 20

2xSF2 Not supported 32

2xSF2 + 2xSF4 Not supported 48

The algorithm selects a user with the largest value of priority and reduces its rate. The users whose GBR are met are downsized before the users whose GBR are not met. When the next period arrives, this user’s CE resources will be called back.

The queuing of users is as follows:

For the users whose Reff is smaller than the GBR, the algorithm queues the users based on Priority = Reff/(γSPI x GBR).

For the users whose Reff is greaterr than or equal to the GBR or the users whose GBR is not configured, the algorithm queues the users based on Priority = Reff/γSPI.

For the users of the serving RLS, the algorithm stops decreasing its CE resources if the CE resources equals to CEinit.

After processing, the algorithm notifies the MAC-e scheduler of the new SGmax.

3. Increasing CE resources of the serving RLS

If the CEavg during the previous period is greater than or equal to CEallocate, the algorithm can increase the CE resources of theses users by one step if there are available CE resources. For example, if the CE resource of a user corresponds to SF4, the algorithm increases the CE resources to that correspond to 2xSF4, as listed in Table 4-1.

The operation of increasing CE resources is based on the user queuing. The users are queued in ascending order based on priority value. The smaller the priority value of a user is, the earlier this user’s CE is increased. The queuing of users is as follows:

For the users whose Reff is smaller than the GBR, the algorithm queues the users based on Priority = Reff/(γSPI x GBR).



4-19

For the users whose Reff is greaterr than or equal to the GBR or the users whose GBR is not configured, the algorithm queues the users based on Priority = Reff/γSPI.

The processing of increasing CE resources is as follows:

The users whose GBR is not reached are increased before the users whose GBR is satisfied or not configured.

During the increasing procedure, the algorithm can preempt the CE resources of the non-serving RLs until their resource decreases to the minimum CE resources, which are required for E-DPCCH demodulation and decoding.

After the increase of CE, the algorithm notifies the MAC-e scheduler of the new allocated CEs and SGmax.

4. Allocating CE resources to non-serving RLs

When there are available CE resources for non-serving RLs, the algorithm allocates them to the users of non-serving RLs.

The algorithm allocates available CE resources as much as possible to non-serving RLs, so that more users can obtain the gain of soft handover.

Based on the CEavg of non-serving RLs during the previous period, the algorithm increases the number of CEs to CEup, where CEup is obtained by increasing CEavg by one step, as listed in Table 1-1.

The users are queued in ascending order based on their priority value. The smaller the value of priority is, the earlier the user is processed. The priority value is calculated as follows:

Priority = CE / γneed SPI

CE = N need RL * (CE - CE )new assign NRL: the number of RLs on the current UL board. CEassign: the CE resource allocated to this user CE = Min[CE , CE , CE ]new up E-DCH MBR Maximum Set of E-DPDCHs

− CEE-DCH MBR: the CE resources corresponding to the E-DCH MBR − CEMaximum Set of E-DPDCHs: the CE resources corresponding to the Maximum Set of

E-DPDCHs − CEup: the CEassign after increasing by a step

γSPI : is the weight of SPI

If the available CE resources can meet the requirements for CEneed of a user, the algorithm allocate the CE resources to this user.

If no enough CE resources are available, the algorithm allocates the minimum CE resources.

After increasing, the algorithm notifies the MAC-e scheduler of the new CEs and SGmax.

5. Allocating the remaining CE resources

This NodeB allocates the remaining CE resources to the users of serving RLS in order to improve the efficiency of utility of CE resources.

NodeB schedules the user of serving RLS by the ascending order of priority until the remaining CE resources are not enough to increase the user by a step or all users have gotten the CE resources of Min[ CE(E-DCH MBR), CE(Maximum Set of E-DPDCHs)].


HSUPA Description


Issue 01 (2008-05-30)

The priority is calculated as follows:

Priority = CEneed / F(SPI), and

Where,

CEneed = NRL * (CEup – CEassign) CEassign is the CE resources allocated to the user of the serving RLS. CEup is the CE resources that are required for increasing the CEassign by a step.

CE Resource Adjustment Triggered by Event When a new RL is admitted, the new RL requests CE resources according to CEinit.

If the CE resources are insufficient, CE preemption is triggered and processed as follows:

The algorithm preempts the CEs of non-serving RLs until their CE resources decrease to the minimum CE number.

If the CE resources are still insufficient after preemption of non-serving RL, the algorithm preempts the CE resources of serving-RLSs until the CE resources decreases to CEinit.

The algorithm preempts the CE resources of users in Type1, then in Type2.

Type1: users with the GBR and Reff ≥ GBR, or the user without GBR Type2: users with the GBR and Reff < GBR

In each type, the algorithm preempts the CE resources according to the priority value of the users:

Priority= Reff / γSPI

Reff, and γSPI are the same as those described in “HSUPA Fast Scheduling”.

4.5 Other HSUPA Related Algorithms This section describes the following HSUPA related RAN features: HSUPA cell load control, HSUPA DCCC, HSUPA power control, HSUPA mobility management, and HSUPA directed retry.

4.5.1 HSUPA Cell Load Control For detailed information about load control, see Load Control.

4.5.2 HSUPA DCCC HSUPA DCCC involves rate reallocation based on throughput, UL BE rate downsizing and recovery based on UL basic congestion, and UE state transition when uplink channel is E-DCH.

For detailed information, see the following descriptions in DCCC of Rate Control:

Rate Reallocation Based on Throughput UL BE Rate Downsizing and Recovery Based on UL Basic Congestion



4-21

UE State Transition Algorithm

4.5.3 HSUPA Power Control HSUPA introduces the five new physical channels. HSUPA power control refers to the power control of these five channels: UL E-DPCCH, UL E-DPDCH, DL E-AGCH, DL E-RGCH, and DL E-HICH.

For detailed information on the HSUPA power control on these channels, see

Power Control on E-DPCCH Power Control on E-DPDCH E-DCH Outer-Loop Power Control Downlink Power Control on E-AGCH, E-RGCH, and E-HICH

4.5.4 HSUPA Mobility Management After HSUPA is implemented, there are two possible connections between the UE and the network. Both HSUPA handover and DPCH handover are controlled by the network through the measurement report of the UE. If HSUPA and DPCH connections are available at the same time, handover decisions for both of them are made individually according to the channel mapping policy and the capabilities of the UE and the cell.

Table 4-2 Connections between UE and network

Connection Handover

HSUPA connection

Similar to handovers in R99-based systems, HSUPA handovers include intra-frequency handover, inter-frequency handover, and inter-RAT handover. The difference is that an HSUPA handover requires the management of the HSUPA serving cell. Cell capacity varies with R6, HSUPA, or others. Therefore, it is necessary to employ the channel mapping policy based on different cell capacity combinations in the active set, to decide whether the services can be carried on E-DCH.

DPCH connection

Similar to handovers in R99-based systems, DPCH handovers include intra-frequency handover, inter-frequency handover, and inter-RAT handover. The difference is whether services are carried on E-DCH according to the channel mapping policy when both the UE and the cell support HSUPA.

The principles of the HSUPA soft handover algorithm are as follows:

The E-DCH active set and the DCH active set are maintained separately. The E-DCH active set is a subset of the DCH active set or the same.

The HSUPA serving cell always tries to change with the best cell in the DCH active set. The type of bearer carrying the uplink services is decided on the basis whether the best

cell in the DCH active set supports HSUPA. If the best cell in the DCH active set supports HSUPA, the uplink services are preferentially carried on the E-DCH. Otherwise, the uplink services are preferentially carried on the DCH.


HSUPA Description


Issue 01 (2008-05-30)

For details, refer to manuals:

Intra-Frequency Handover Inter-Frequency Handover SRNS Relocation

4.5.5 HSUPA Directed Retry With the feature of directed retry, resources can be shared between R99 and HSUPA cells or, between HSUPA cells.

To support directed retry, the DRD_SWITCH needs to be enabled.

Directed Retry from an R99 Cell to an HSUPA Cell Suppose that an R99 cell and a neighboring HSUPA cell cover the same physical area and one is the other’s DRD neighboring cell. Directed retry is triggered in the following cases:

In the R99 cell, the UE initiates a service that has to be set up on the E-DCH according to the service mapping rules.

The traffic volume of the UE increases when the UE stays in CELL_FACH state in the R99 cell, and the service fulfills the criteria of service mapping to HSUPA.

The associated timer expires. For a service that must be set up on the E-DCH according to the service mapping rules, it can be set up on the DCH of the R99 cell because, for example, the admission request is rejected. Under such a circumstance, the system starts a timer for the inconsistency between the channel that is suitable for the service and the channel that carries the service. The length of this timer is defined by the H Retry timer length parameter.

DRD is enabled after the relative switch is on:

If DRD_SWITCH, HSUPA_DRD_SWITCH and INTRA_HO_D2H_DRD_SWITCH are enabled, DCH to HSUPA retry is allowed only when it is required after a soft handover or an intra-frequency hard handover.

If DRD_SWITCH, HSUPA_DRD_SWITCH and INTER_HO_D2H_DRD_SWITCH are enabled, DCH to HSUPA retry is allowed only when it is required after an inter-frequency hard handover.

Directed Retry Between Two HSUPA Cells Assume that two neighboring HSUPA cells cover the same physical area and one cell supports HSUPA DRD. If both DRD_SWITCH and HSUPA_DRD_SWITCH are enabled, directed retry is allowed only when it is required.

Directed retry is triggered in the following cases:

The access to an HSUPA cell is rejected when the service is set up. The access to an HSUPA cell is rejected when the channel switching from FACH to

E-DCH is triggered by the increase of the traffic volume. The access to an HSUPA cell is rejected when the channel switching from DCH to

E-DCH is triggered.

When one of the preceding conditions is met, the system assigns the service to the E-DCH of the other HSUPA cell through directed retry.



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For detailed information of the following parameters, refer to Load Control:

DRD_SWITCH INTRA_HO_D2H_DRD_SWITCH INTER_HO_D2H_DRD_SWITCH HSUPA_DRD_SWITCH

RAN HSUPA Description 5 HSUPA Reference Documents


5-1

5 HSUPA Reference Documents

HSU cuments lists 3GPP protocols and documents related to HSUPA.

and reception (FDD) transport channels onto physical

l coding (FDD)

d principles 3GPP TS 25.423: UTRAN Iur interface RNSAP signaling 3GPP TS 25.430: UTRAN Iub interface: general aspects and principles 3GPP TS 25.433: UTRAN Iub interface NBAP signaling

PA Reference Do

3GPP TS 25.101: User Equipment (UE) radio transmission 3GPP TS 25.211: Physical channels and mapping of

channels (FDD) 3GPP TS 25.212: Multiplexing and channe 3GPP TS 25.213: Spreading and modulation (FDD) 3GPP TS 25.214: Physical layer procedures (FDD) 3GPP TS 25.309: FDD Enhanced Uplink 3GPP TS 25.301: Radio Interface Protocol Architecture 3GPP TS 25.302: Services provided by the physical layer 3GPP TS 25.321: Medium Access Control (MAC) protocol specification 3GPP TS 25.420: UTRAN Iur interface general aspects an

HSUPA Description(2008!05!30)

Documents

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