wr_bt10_e1_1 hsupa principle 59.pdf

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HSUPA Principle

ZTE University

2009-8-10

HSUPA Basic Principle

HSUPA Key Technologies

HSUPA Performance Analysis

HSUPA Evolution Strategy

Content

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HSUPA Protocol Architecture

UE: New MAC entity MAC-es/MAC-e is introduced under MAC-d, in charge of HARQ rapid retransmission, scheduling, data multiplexing and E-TFC (E-DCH TFC) selection. Node B: New MAC entity MAC-e is introduced, in charge of HARQ re-transmission, scheduling, and MAC-e de-multiplexing. SRNC: New MAC entity MAC-es is added to provide re-ordering and macro diversity combination in case of soft handover

PHY PHY

EDCH FP EDCH FP

IubUE NodeBUu

DCCH DTCH

TNL TNL

DTCH DCCH

MAC-e

SRNC

MAC-d

MAC-e

MAC-d

MAC-es / MAC-e

MAC-es

Iur

TNL TNL

DRNC

HSUPA Technical Features

In UE, dedicated physical data channels (E-DPDCH, at most 4

for each UE) and a dedicated physical control channel (E-

DPCCH) to be added in the uplink. Common physical channels

(E-HICH, E-AGCH and E-RGCH) to be added in the downlink.

E-DPDCH bears uplink data with SF=2 or 4, QPSK modulation

and 2ms TTI, it remains 10 ms TTI.

E-DPCCH, E-HICH, E-AGCH and E-RGCH accomplish the

HARQ and information exchange (including ACK/NACK, uplink

grants, and signaling control related to E-DCH)

The maximum rate of each E-DPDCH is 1.92 Mbps (2ms TTI,

QPSK, SF=2). The maximum traffic rate of each UE is 5.7Mbps.

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MAC layer Architecture in UE side

New MAC-es/MAC-e entity is introduced to control E-DCH in UE side.

in charge of HARQ rapid retransmission, scheduling, data multiplexing and E-TFC (E-DCH TFC) selection.

Associated Downlink Signalling

E-DCH

MAC-d

FACHRACH

DCCH DTCHDTCH

DSCH DCH DCH

MAC Control

USCH ( TDD only )

CPCH ( FDD only )

CTCHBCCHCCCH SHCCH( TDD only )

PCCH

PCH FACH

MAC-c/sh

USCH ( TDD only )

DSCH

MAC-hs

HS-DSCHAssociated

Uplink Signalling

Associated Downlink Signalling

MAC-es / MAC-e

Associated Uplink

Signalling

Structure of MAC-e/MAC-es entity in UE side

MAC - es/e

MAC – Control

Associated Uplink Signalling E- TFC

(E- DPCCH)

To MAC -d

HARQ

Multiplexing and TSN settingE- TFC Selection

Associated Scheduling Downlink Signalling

(E- AGCH / E - RGCH(s) )

Associated ACK/NACKsignaling

(E- HICH)

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Functions of MAC-e/MAC-es entity in UE side

HARQ entity: control the re-transmission of MAC-e PDU. The copy of MAC-e PDU is saved in the buffer of HARQ entity. The copy of MAC-e PDU will be re-send when the NACK is received from the peer HARQ entity. HARQ protocol is configured by the MAC-Control SAP of RRC。HARQ provides E-TFC, retransmission serial number (RSN) and the power offset used by L1.

Multiplexing and TSN setting entity: in charge of multiplexing multiple MAC-d PDUsinto one MAC-es PDU, and multiplexing multiple MAC-es PDUs into one MAC-e PDU. Which is processed under the guide of E-TFC selection. It is also in charge of setting and management of the TSN of logical channel.

E-TFC selection entity: select the E-TFC according to the scheduling indication (Relative Grants and Absolute Grants) of Node B, and control the Multiplexing. consequently decide the mapping relationship from different MAC-d to E-DCH. E-TFC is configured by the MAC-Control SAP of RRC.

PDU Processing of MAC layer in UE side

MAC-d Flows

MAC-es PDU MAC-e header

DCCH DTCH DTCH

HARQ processes

Multiplexing

DATA

MAC-d DATA

DATA

DDI N Padding (Opt)

RLC PDU:

MAC-e PDU:

L1

RLC

DDI N

Mapping info signaled over RRC PDU size, logical channel id, MAC-d flow id => DDI

DATA DATA

MAC-d PDU:

DDI

Header

MAC-es/e

Numbering MAC-es PDU: TSN DATA DATA Numbering Numbering

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Structure of MAC layer in UTRAN side

In UTRAN side, MAC-e is located in Node B, MAC-es is located in SRNC.MAC-e of Node B is in charge of HARQ retransmission, scheduling, MAC-e de-multiplexingMAC-es of SRNC is in charge of re-ordering and macro diversity combination.MAC-e controls the access of E-DCH, connecting to MAC-es, connecting from MAC-es to MAC-d.New connection is defined in MAC-e and MAC Control SAP, also in MAC-esand MAC Control SAP.

Function and Structure of MAC-es in UTRAN side

MAC-es

MAC – Control

From MAC-e in NodeB #1

To MAC-d

Disassembly

Reordering Queue Distribution

Reordering Queue Distribution

Disassembly

Reordering/

Combining

Disassembly

Reordering/ Combining

Reordering/Combining

From MAC-e in NodeB #k

MAC-d flow #1 MAC-d flow #n

Re-ordering queue distribution entity: routing MAC-es PDU to the correct re-ordering buffer according to the configuration of SRNC.Re-ordering entity: re-ordering the received MAC-es PDU according to the received TSN and Node B ID.Macro diversity selection entity:selective combining for MAC-esPDU from multiple Node B in case of soft handover. MAC-es PDU disassembling entity: disassemble MAC-esheader, transmit MAC-d PDU to MAC-d layer.

Function entity of MAC-es in SRNC side: Function entity of MAC-es in SRNC side:

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Function and Structure of MAC-e in UTRAN side

MAC-e

MAC –Control

E-DCHAssociated Downlink Signalling

Associated Uplink

Signalling

MAC-d Flows

De-multiplexing

HARQ entity

E-DCHScheduling E-DCH

Control

Function entity of MAC-e in Node B side:Function entity of MAC-e in Node B side:

E-DCH scheduling and control entity: base on the scheduling request SR (Scheduling Request) from UE, allocate resource for UE, and notify UE though downlink resource indication.De-multiplexing entity: de-multiplexing MAC-e PDU, and save the de-multiplexed SI which is referenced by E-DCH scheduling entity.HARQ entity: processing multiple stop-wait :HARQ processes, produce ACK or NACK, indicate if the data transmitted on E-DCH is correct, count the times of re-transmission which is referenced by Scheduling entity.

HSUPA new transmission channel E-DCH

E-DCH and DCH use separated CCTrCHs.

Each UE only has one CCTrCH with E-DCH type.

Each CCTrCH with E-DCH type only has one corresponding E-DCH.

Each TTI only has one transmission block.

E-DCH supports 2ms TTI and 10ms TTI, 10ms TTI is mandatory to all

UE, 2ms TTI is optional.

Adopts Turbo 1/3 coding method.

After E-DCH is allocated, the data rate of original uplink DCH will be

restricted in 64kbps.

E-DCH attributes

Both uplink logical channel DCCH and DTCH can be mapped to E-DCHBoth uplink logical channel DCCH and DTCH can be mapped to E-DCH

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HSUPA new physical channel

Five physical channels are added in radio interface to support rapid re-

transmission, soft combination and Node B distributing scheduling in

physical, these five physical channels all support 10ms TTI and 2ms

TTI.

E-DPDCH: E-DCH Dedicated Physical Data Channel (uplink).

E-DPCCH: E-DCH Dedicated Physical Control Channel (uplink).

E-HICH: E-DCH HARQ acknowledgement Indicator Channel

(downlink).

E-AGCH: E-DCH Absolute Grant Channel (downlink).

E-RGCH: E-DCH Relevant Grant Channel (downlink).

Uplink dedicated physical channel E-DPDCH and E-DPCCH

Bear HSUPA uplink data.Alterable SF＝2～256.Adopt QPSK modulation.Support 10ms TTI and 2ms TTI.Each radio link has one or multiple E-DPDCH.

E-DPDCH is a uplink dedicated physical data channel to bear the data of E-DCHE-DPDCH is a uplink dedicated physical data channel to bear the data of E-DCH

E-DPCCH is a uplink dedicated physical control channel bearing control information of E-DCHE-DPCCH is a uplink dedicated physical control channel bearing control information of E-DCH

Bear HSUPA uplink control information. Fixed SF＝256.Adopt QPSK modulation.Support 10ms TTI and 2ms TTI.Each radio link has one E-DPCCH.

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Downlink common physical channel E-AGCH

Slot #1 Slot #14 Slot #2 Slot #iSlot #0

Tslot = 2560 chips

1 subframe = 2 ms

1 radio frame, Tf = 10 ms

E-AGCH 20 bits

Adopt fixed SF=256, the channel speed is 30kbps.E-AGCH is only existing in serving E-DCH cell.Absolute Grant of E-DCH is only transmitted in serving E-DCH cell.Absolute Grant can be transmitted in one sub-frame (2ms TTI) or one radio frame (10ms TTI).

E-AGCH is a downlink common physical channel to bear the absolute grant of E-DCHE-AGCH is a downlink common physical channel to bear the absolute grant of E-DCH

Downlink dedicated physical channel E-RGCH

Slot #14

Tslot = 2560 chip

bi,39 bi,1 bi,0

Slot #0 Slot #1 Slot #2 Slot #i


1 subframe = 2 ms

E-RGCH is a Downlink dedicated physical channel to bear the relative grant of E-DCHE-RGCH is a Downlink dedicated physical channel to bear the relative grant of E-DCH

Adopt fixed SF=128.A relative grant can be transmitted in 3, 12 or 15 continuous time slots. 3 and 12 time slots are corresponded to 2ms TTI and 10ms TTI in serving E-DCH cell, 15 time slots is used in non-serving E-DCH cell.

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Downlink dedicated physical channel E-HICH

Slot #14

Tslot = 2560 chip

bi,39 bi,1 bi,0

Slot #0 Slot #1 Slot #2 Slot #i


1 subframe = 2 ms

E-HICH is a Downlink dedicated physical channel to bear the HARQ acknowledgement Indicator of E-DCHE-HICH is a Downlink dedicated physical channel to bear the HARQ acknowledgement Indicator of E-DCH

Adopt fixed SF=128.A HARQ acknowledgement Indicator can be transmitted in 3 or 12 continuous time slots, which are corresponded to 2ms TTI and 10ms TTI.E-HICH and E-RGCH have the same SF and radio frame structure, they are differentiated by different signature sequence.

Basic Concept

Serving E-DCH cell: Serving E-DCH cell:

The cell where the UE receives AGs (absolute grants). One UE has only one

serving E-DCH cell.

Serving E-DCH RLS or Serving RLS:Serving E-DCH RLS or Serving RLS:

A set of cells that have E-DCH serving cell, one UE has only one serving RLS,

UE can receive and combine a relevant grant under serving RLS.

Non-serving E-DCH RLS or Non-serving RLS：非服务E-DCH RLSNon-serving E-DCH RLS or Non-serving RLS：非服务E-DCH RLS

A set of cells that have no E-DCH serving cell, One UE can has zero, one or

multiple non-serving RLS, UE can only receive a relevant grant under Non-

serving RLS.

E-DCH active set: E-DCH active set:

A set of cells that have E-DCH bearer between the UE.

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HSUPA basic principle SRNC DRNC

MAC-es FP

MAC-d

NodeBs Iur/Iub FP

Scheduler

MAC-e

NodeBd FP

MAC-e

UE MAC-e/ MAC-es

MAC-d

DTCHs

E-DPDCH E-DPCCH

E-AGCH (Absolute Grants, "E-RNTI" -> UE)

serving cell

E-HICH (ACK/NACKs) E-RGCH (relative grants) (ChCode, signature -> UE)

MRC MRC

1 TNL bearer per MAC-d flow

Iur/Iub FP

Serving RLSServing RLS

Non-serving RLS

Non-serving RLS

E-DCH Active SetE-DCH

Active Set

E-DCH Serving Cell

E-DCH Serving Cell

HSUPA working principle under soft handover

HSUPA working principle under soft handover

Only one cell is in charge of E-DCH scheduling under the state of non-soft handover, that is E-DCH serving cell.

HSUPA basic working process (1)

UE sends service request to network side as the same process of R99/R4.

Upon receiving RAB establishment request, the SRNC determines to select uplink E-DCH according to service attributes and sends the RL SETUP message to NodeB. The RL SETUP message indicates which RL is the E-DCH RL and which RL is the serving E-DCH RL.

After establishing RL, the NodeB sends RL SETUP response to RNC. The response message contains the E-AGCH/E-RGCH/E-HICH scramble and channelization code, and E-RGCH/E-HICH signature sequence. If the RLs contain the serving RL, the NodeB allocates E-RNTI to the UE. The response message also contains the E-RNTI.

The RNC sends UE the RB SETUP message, carrying E-RNTI, mapping relationship between RB and Mac-d Flow, E-TFCS, Mac-d Flow, E-AGCH/E-RGCH/E-HICH code resource and signature information.

Establishing process of dedicated channel E-DCHEstablishing process of dedicated channel E-DCH

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UE has a E-DCH serving cell, the scheduling is processed by the Node B which the E-DCH serving cell belongs to. E-DCH serving cell sends scheduling command to UE by E-AGCH, that is Absolute Grant, AG limits the maximal resource that UE can use, AG includes the E-RNTI of UE, and the maximal transmitting power that UE allows, etc.

E-DCH serving cell and E-DCH non-serving cell send Relative Grant though downlink channel E-RGCH, Relative Grant is a offset to Absolute Grant (tiny tuning), its value can be “Up”, “Hold”, or “Down“. Serving E-DCH RLS can sends all these 3 values. Non-Serving E-DCH RLS can only send “HOLD” or “DOWN”. Usually, the reason of sending “DOWN” by non-Serving E-DCH RLS is uplink overload.

E-DCH scheduling process E-DCH scheduling process


According to the grant information received, the UE selects E-TFC. It sends data (including data resent) in E-DPDCH, and E-TFC information, HARQ RV information (RSN), and a Happy bit in E-DPCCH. The Happy bit notifies Node B whether the UE is satisfied with the current resources (grant) allocated, that is, whether higher grant is required.

Firstly, the E-DCH data received from the different cells under the same Node B of E-DCH Set is combined (MRC Combination), and then the data is sent to Mac-e for processing. Each UE has a Mac-e in each Node B. The Mac-e de-multiplexes the Mac-e PDU to MAC-es PDU and sends it to RNC. The Mac-e also sends E-DCH scheduling information and the ACK/NACK of HARQ.

Each UE has a Mac-es entity in SRNC. When receiving MAC-es PDUs from different Node Bs, the Mac-es performs macro diversity combination, re-sorts their order, divides them into Mac-d PDUs, and sends them to Mac-d.

HARQ process: The UE sends HARQ RV (retransmission serial number, RSN) through uplink E-DPCCH. The Node B sends the ACH/NACH through downlink E-HICH.

E-DCH data transmission and retransmission processE-DCH data transmission and retransmission process

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HSUPA physical channel forming process

E-DPDCH Fixed reference channel 3 (FRC3)E-DPDCH Fixed reference channel 3 (FRC3)

Information Bit Payload NINF = 8100

CRC Addition

3 x (NINF+24)/2 = 12186

Code Block Segmentation (8100+24)/2 = 4062

Turbo Encoding (R=1/3)

RV Selection 11520

Physical Channel Segmentation 3840

24NINF = 8100

12

(8100+24)/2 = 4062

3840 1920 1920

3 x (NINF+24)/2 = 12186 12

SF=4SF=4SF=2SF=2

2ms subframe 2ms subframe

HSUPA UE Category

2Mbps/5.76Mbps20000/1148410ms, 2ms2×SF2＋

2×SF4Category 6

2Mbps2000010ms2×SF2Category 5

2Mbps/2.9Mbps20000/577210ms, 2ms2×SF2Category 4

1.45Mbps1448410ms2×SF4Category 3

1.45Mbps/1.42Mbps14484/279810ms, 2ms2×SF4Category 2

0.71Mbps711010ms1×SF4Category 1

Data Rate(10ms/2ms)

Max. Transmission Block Size (bit)

(10ms/2ms)TTICodes X

SpreadingE-DCH

Category

Remark: Data Rate = (Max. Transmission Block Size + 36bit CRC) / TTI

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2009-8-10

Content





HARQ – Fast Hybrid Automatic Repeat Request

HARQ is an error correction technology. The "hybrid" is the combination of forward error correction (FEC) and automatic repeat request (ARQ)

HARQ function is located in MAC-e entity of Node B and UE.

The fast HARQ of HSUPA is implemented by adding an HARQ functional entity in Node B. If data is not received correctly, the Node B will request the UE to resend the uplink packet data.

In uplink, HARQ adopts the N channel Stop And Wait (NSAW) protocol.

In HSUPA, 10ms TTI corresponds to 4 HARQ processes, and 2ms TTI to 8 HARQ processes.

HARQ - Reduce transmission delay and improve throughput of UE and systemHARQ - Reduce transmission delay and improve throughput of UE and system

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HARQ retransmission combination

The forward error correction of uplink HARQ provides two modes, namely, Chase Combining (CC) and Incremental Redundancy (IR) The information resented by CC mode has the same content as the original information, which is processed with maximal ratio combining before UE decodes it. Thus, the decoding grain is increased. The IR retransmission supports two retransmission modes:

The IR enables different redundancy information to be sent in retransmission. Thus, the data cannot be decoded unless the data sent by the first time and that retransmitted are combined. The IR also enables the same redundancy information to be sent in retransmission. However, that information can be self-decoded. With incremental redundancy given in each HARQ retransmission, the forward error correction capability is enhanced.

Node B uses different ways to combine the multiple retransmissions of a single packet, decrease the receive Ec/No of each transmission. With HARQ, HSUPA can effectively increase data transmission rate and shorten transmission delay.

Node B uses different ways to combine the multiple retransmissions of a single packet, decrease the receive Ec/No of each transmission. With HARQ, HSUPA can effectively increase data transmission rate and shorten transmission delay.

Retransmission comparing between HSUPA HARQ and R99 RLC

The fast HARQ may cause higher target block error rate (BLER) in the first transmission, because it enables shorter delay in resending the packets that are not correctly received previously compared with RLC retransmission. The higher BLER target can reduce the transmit power that is required by the UE in transferring the data of certain rate. Therefore, for the same cell load, the fast HARQ can increase the cell capacity. When the data rate is fixed, the energy decreasing of each bit can improve the coverage.

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Uplink HARQ Soft HandoffIn CDMA system, the software handoff gain is generated when a Node B receives packets correctly, while another Node B cannot decode. In the soft handoff of HSUPA HARQ, one Node B sends acknowledgement (ACK) to the UE, while the other one sends negative acknowledgement (NACK). In this case, the network already receives the packet, and the UE should not sent the same packet. Accordingly, the HARQ process of the Node B that receives packet incorrectly can resume from the reception failure. The RNC must ensure the sequence of the packet and send it to the upper layer, and performs selective combination of the packets received from different Node Bs.

In the process of SHO, UE can perform retransmission only when all Node Bs in the active set

can’t decode correctly, otherwise, UE will not perform retransmission if there is one ACK.

SHO enables link diversity gain, improves throughput effectively, and reduces retransmission

times.

Fast Packet Scheduling

To R99/R4/R5, packet scheduling is based on RNC. In HSUPA, the scheduling is located in Node B, and the scheduling period can be 2ms, to implement fast scheduling strategy, thus, the uplink air interface capacity can be effectively utilized.

The packet scheduling controlled by RNC will cause some delay, so the change of current channel can not be reflected quickly, thus, the fast link self-adaptation and fast packet scheduling can not be performed.In HSUPA, the packet scheduling entity of Node B can directly use real-time measurement information of physical layer, inner statistic information and the information reported by UE to perform scheduling, thus, to reduce the system transmission delay by utilizing the situation of channel and fading attribute of different users.

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Fast Uplink Packet Scheduling

As serving Node B, Allocate uplink resource to the UEs under serving E-DCH cell.

As non-serving Node B, detect the interference of other cells and send relative grant

information to UEs.

Notify SRNC while there is short of processing resource.

Uplink and downlink radio packet scheduling have the different complication of resource controlling.Uplink and downlink radio packet scheduling have the different complication of resource controlling.

In downlink: Node B can easily get the information of buffer occupation of each service streaming, and the downlink power is central controlled, so Node B can allocate and free the power resource accurately, thus to control the system load efficiently and ensure the QoS of each service.In Uplink: the time delay and uncertainty are existed in uplink service streaming cause the information of it need to be reported to Node B by radio channel. In uplink, each UE has its own power source, because of the time variability of radio channel and the limitation of code resource, the accurate control of uplink system resource (total uplink power) became more complicated, so as to the uplink packet scheduling.

The function of Node B scheduler:

Uplink Packet Scheduling Model

In order to confirm the uplink transmission rate and transmitting power, some information of user must be known like the situation of serving streaming and available power, etc. which is named SI (Scheduling Information).SI is periodically reported in HSUPA, and the period of report is integral times of TTI, SI is multiplexed with packet data.Node B allocates uplink resource to user according to the SI information multiplexed from received data, that is, Node B sends resource indication of scheduling Absolute Grant by downlink AGCH channel.

……

……

……

Service queue of user 1



Radio C

hannel

Code resource management

Resourceallocation

Link qualitydetection

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Scheduling Resource CompensationMechanism

In HSUPA, Node B performs tiny tuning to the resource allocated to UE by sending Relative Grant through RGCH channel

The error of SI transmission is unavoidable and the report is unreliable cause of being transmitted by the radio channel.Node B adopts periodical scheduling, but the SI may be not accurately reflect the UE situation at real time.While the situation of radio channel is bad, the SI will not be received correctly before it has been multiple retransmitted. That causes time delay.

The shortage of SI transmissionThe shortage of SI transmission

Compensation MechanismCompensation Mechanism

Scheduling Resource CompensationProcess

UE reports Happy bit to Node B in E-DPCCH, Happy bit has 1 bit to indicate if UE is satisfied with the allocated resource. After UE received the resource indication, it will make a judgment according to the following principle:

UE has surplus power for the scheduling resource. The required time for transmitting all the data in buffer will exceed 1 TTI by using the allocated power resource.

UE will express its “un-satisfaction” to Node B by Happy bit, and will require more resource to be allocated.If UE report “satisfy”, then Node B will indicate to keep the current allocated resource.

Packet scheduling is not simply adjust the resource of UE according to the

situation of UE, it will integrate with the system load, channel state and

QoS of different service, etc. it’s a balance between system indices

(system throughput, fairness) and service QoS (time delay, packet missing

rate).

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Packet Scheduling Priority Allocation

In the process of packet scheduling, the most important thing is how to decide the sequence for the users who are striving for resources, so the system resource can be efficiently utilized, the system throughput will reach its maximum state, and try best to make every user satisfied.

In 3GPP, there are two arithmetic that determine the performanceboundary.

One is base on C/I, it provides maximal system throughput while lost its fairness.

Another is RR, it provides equal chance to every user, but the system throughput is bad.

The popular scheduling arithmetic include Round Robin, Max C/I and Proportional Fair, they all can be regarded as scheduling base on Priority, but their allocation strategy is different.

Uplink Noise Rising probability

The obvious reduction in scheduling period enables the uplink air interface capacity to be better controlled dynamically, and the resource of air interface will be effectively utilized.

The potential advantage is that the running target of uplink load can be more approached to the maximal level of load, but it will not improve the probability of overload, thus, the probability of uplink noise rising is lower than that caused RNC scheduling.

When UE stop transmitting or reduce transmission data rate, Node B scheduler can allocate the released capacity to other UE quickly and effectively.

Comparison of Uplink Noise Rising probability between RNC scheduling and Node B schedulingComparison of Uplink Noise Rising probability between RNC scheduling and Node B scheduling

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Effect of Fast Packet Scheduling on Maximum Expected Load

The probability of uplink load target is much more near that of maximum load limit when the marginal load area becomes smaller (The Prx_target is more closer to the Prx_threshold. The Prx_threshold is the overload threshold).

The Node B-based scheduling requires the information related to UE uplink transmission demand. The UE should be informed of the current data rate allowed through fast signaling within specified time.

To RNC, these operations are implemented through RRC signaling, the response speed of which is restricted obviously.

2ms TTI

114842000010 ms and2 ms TTISF24Category 6

-2000010 ms TTI onlySF22Category 5





Max. transmission block size(2ms TTI)

Max. transmission block size(10ms TTI)

TTI typeMin.

Spread Factor

Max.E-DCH

channelsE-DCH type

As a option, a shorter 2ms TTI is described in uplink of HSUPA to decrease the HARQ retransmission delay.

When each TTI contains the same amount of data, the energy transmitted in 2 ms is less than that in 10 ms possibly, and the interleaving gain decreases. Therefore, to ensure normal operation in cell edge, 10 ms TTI must be used.

when there is no other constraint like link coverage, 2ms TTI helps increase system capacity. In favorable radio environment, 2ms TTI can bring higher peak rate.

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2009-8-10





Content

Influence of the Introduced HSUPA on Original Network

Occupy downlink code resource.

Occupy downlink power resource.

increase the uplink interference of network, impact on link

budget, capacity and coverage.

impact on terrestrial transmission bandwidth.

Influence of HSUPA on Network includes: Influence of HSUPA on Network includes:

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Influence of the Introduced HSUPA on R99/R4/R5

The new function, new physical channel and new MAC entity are added. The data rate in the

uplink is enhanced. It is necessary to upgrade the software of Node B and RNC. It also

requires the new terminal to support the HSUPA.

Higher data rate may require higher baseband capacity and function. It may be necessary to

change the hardware in Node B and RNC, but not compulsory.

Influence on Iu* Interface:Influence on Iu* Interface:

Influence on Iub/Iur Interface: Control plane: Add the IEs that are related to configuring and controlling E-DCH channel and resource, and the Node B scheduling operation and MAC Multiplexing, etc. User plane: Add new frame structure for E-DCH, support 2ms and 10ms TTI.

Influence on Iu Interface: there is no influence on Iu interface.

Influence of HSUPA on Network Planning –Coverage and Link Budget

In consideration of the fact that the HSUPA provides the uploading service for VIP customers in core urban areas, it is advisable to select the dense urban area model to conduct HSUPA link budget. In order to conduct the planning comparison with R99, here we compare the typical uplink service of the independent R99 planning with the link budget of the HSUPA uplink service and analyze them. There is sufficient reservation for the shadow margin and the penetration margin in the table in order to reflect the dense urban area model. The COST231 path loss model is also used in calculating the coverage radius.

coverage situation of high speed HSUPA service

coverage 0.51.1SF1 = 2，SF2 =

21920Mode4

Medium and high speed 0.51.05SF1 = 4，SF2 = 4960Mode3

Medium and low speed 0.50.95SF1 = 4480Mode2

coverage situation at the edge of low speed HSUPA service 0.2670.8SF1 = 1664Mode1

Remark Coding Efficiency

Eb/No (dB)Spread FactorBitrate

kbpsHSUPA mode

4 modes are set by HSUPA, the detail information of HUSPA of each mode is:

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Uplink Link Budget Comparison between HSUPA and R99

0.1929370.2356650.237210.4244370.4900830.451040.447171Coverage radius (km)

115.0773118.1376118.2376127.1382129.3382128.0682127.9364Maximal allowed path loss

20202020202020Penetration loss

10101010101010Shadow fading margin

2222222Soft handover gain

3333333Power control margin

Others

18181818181818Antenna gain (dbi)

-104.077-107.138-107.238-116.138-118.338-117.068-122.936Receiver sensitivity

1.11.050.950.81.62.874.2Receiving Eb/No (db)

6.02069.03099.030917.7815117.7815117.7815124.97971Processing gain (db)

192096048064646412.2Bit rate (kbit)

2211111Code channel quantity

6666333Interference margin (db)

-105.157-105.157-105.157-105.157-105.157-105.157-105.157Receiver noise (dbm)

3333333Receiver noise coefficient (db)

-108.157-108.157-108.157-108.157-108.157-108.157-108.157Thermal noise power (dbm)

-174-174-174-174-174-174-174Thermal noise power spectrum density (dbm/HZ)

Receiving end

24242424242418Effective transmission power

0000003Human body loss (db)

0000000Antenna gain (dbi)

24242424242421Maximal transmission power (dbm)

Transmission end

mode4mode3mode2mode1ps64kcs64kcs12.2k

HSUPAR99

Uplink Link Budget Comparison and Analysis between HSUPA and R99

As shown in the prior table, the 12.2k, 64k service of R99 almost have the same coverage, the radius of dense urban is about 450m, the distance between two sites is about 780m. The low speed HSUPA service (mode1) can have the same coverage as 12.2k.

In mode2, it is very hard to bear 480kbps, because there is only one SF code. And the radius of coverage is shrunk to about 240m.

In mode3, for the bearing speed is improved and the SF code is increased to 2, the radius of coverage can be kept in about 240m.

For the high speed uplink service (mode4), the bearing speed is improved to 2Mbps with 2 SF codes, And the radius of coverage is shrunk to about 190m.

The interference margin of R99 link budget that the prior table corresponds to is 3dB, and that of HSUPA is 6dB (HSUPA can more effectively control system overload probability under the same average interference margin requirement).

23

Link Budget Comparison of HSUPA/R99 in Co-frequency Networking Mode

0.1929370.2356650.237210.4244370.4028120.3707220.367542Coverage

radius (km)

115.0773118.1376118.2376127.1382126.3382125.0682124.9364Maximal allowed

path loss

mode4mode3mode2mode1ps64kcs64kcs12.2k

HSUPAR99

According to link budget, under the co-frequency situations, the introduction of the relatively high interference margin threshold causes R99 service coverage radius shrinkage. The 12.2k service radius shrinks by 10% ~ 20%. In this network planning, HSUPA 64k service, or service whose rate is slightly higher than 64k can reach the whole network coverage. The peak 1,920 kbps service coverage radius can reach 50% of the planned cell radius, that is, it can cover about 25% of the area of the whole cell. Through the above analysis, it can be known that the low speed HSUPA service (Mode 1) can basically guarantee to maintain the same coverage relation with planned R99 coverage range when HSUPA and R99 jointly conduct the uplink planning. When HSUPA user rate rises, its service coverage shrinks. At the same time, as the HSUPA is introduced, in co-frequency construction, planned R99 range will somewhat shrink.

Summary of HSUPA impacting on Network Planning and Analysis

HSUPA network construction strategy: Cover the whole network with relatively low rate. Focus on the coverage of dense urban areas, to ensure the high rate of uplink transmission in hotspot areas. It is recommended that for the planning the initial stage, it is advisable to refer to HSDPA coverage range, conduct key coverage in hotspot areas, and just conduct the low speed coverage in the edge areas of common cell. In HSUPA planning, under the conditions that the same overload probability is ensured, and RRM control algorithm is further optimized, in order to enhance uplink throughput, in setting uplink interference margin, it is recommended not to use the common R99 uplink 3dB as the noise raise threshold, and the value 5 ~ 6dB is recommended. In the co-frequency planning of HSUPA and R99, if the interference margin threshold is raised, it will cause the previous R99 uplink planned budget radius to shrink. As to how much it will shrink specifically, it is necessary to conduct subsequent and further study. From link budget analysis, it shrinks by about 10 ~ 20%. In inter-frequency networking, there is basically no influence on R99 uplink planning.Via the link budget, it can be known that HSUPA 64k service budget radius is slightly smaller than R99 12.2k and 64k service radiuses under the inter-frequency HSUPA networking conditions; HSUPA 64k service budget radius is slightly bigger than R99 12.2k and 64k service radiuses under the co-frequency networking conditions. Analyzed in a comprehensive manner, the low speed HSUPA service can implement the same coverage with the planned R99 range.

HSUPA impacting on Network Planning and Analysis includes: HSUPA impacting on Network Planning and Analysis includes:

24

HSUPA theoretic data rate

5742.00.99115204422114842FRC4

69.00.28824000001669010FRC81927.80.5023840000221927810FRC7978.00.509192000044978010FRC6507.60.52996000004507610FRC5

4050.00.70311520442281002FRC32706.00.7057680002254122FRC21353.00.7053840004427062FRC1

Max inf bit rate [kbps]

Coding rateNBINSF4SF3SF2SF1NINF

TTI [ms]

Fixed Ref Channel

HSUPA Enhanced Uplink Dedicated Physical Channel E-DPDCH supports SF=2～256, and multiple channels. Adopts QPSK modulation and coding rate 1/3 (turbo). If the coding rate is 1, then the maximal transmission capacity of Enhanced Uplink Dedicated Physical Channel is up to 5.76Mbit/s by data rate matching arithmetic。

Remark：Coding rate=NINF/ NBINNBIN=3840 / SF x TTI sum for all channels

HSUPA data rate transmission efficiency (1)

HSUPA complies with the HARQ protocol, generating performance gain for EDCH via link level retransmission and retransmission times. As the fast feedback retransmission of the physical layer reduces the RLC retransmission and the corresponding delay, it is possible to effectively improve the service experience of end users. It can enable HSUPA physical channel to work in the channel whose bit error ratio is relatively high, thus improving the system capacity. When the uplink uses the inner loop power control, the retransmission ratio of the initial transmission can reach 10-30% to maintain the given quality grade. A large quantity of retransmission will lead to the decline of the throughput of end users, while excessively low retransmission ratio will not generate any gain of any relatively previous version for the HARQ controlled by Node B. Soft combination can further improve the system performance of HARQ mechanism controlled by Node B. The HSUPA adopts the synchronous HARQ, and there are strict timing relations for the operations of different HARQ processes. The synchronous HARQ effectively lowers the signaling overhead caused by HARQ operation, thereby improves system capacity. HARQ is mainly used in interactive, background and streaming services. Therefore, to adopt HARQ in HSUPA, attention should be focused on the following:

Delay reduction More users and improvement of system throughput

HARQ InfluenceHARQ Influence

25


Soft Combining Influence of HARQSoft Combining Influence of HARQ

Ped A 3km/h, 144kbps/480kbps, real CE, 4% TPC error

0

100

200

300

400

500

-22 -20 -18 -16 -14 -12 -10 -8 -6 -4

received Ec/No [dB]

Thro

ughp

ut [k

bps]

CC(480kbps)NC(480kbps)CC(144kbps)NC(144kbps)

Throughput comparison under PA 3km/h Conditions

In the HARQ protocol, it is necessary to retransmit the data that can not be correctly received. And it is possible to generate the gain in throughput for the UE whose transmission power is limited by using Soft Combining, and the retransmission times can be effectively reduced.The algorithm which adopts the soft combining brings much more gain than that which does not adopt the soft combining. This is because that the soft combing fully utilizes the bit information of the previous transmission. Therefore, the gain is more remarkable when the Ec/No is relatively low.


When macro diversity technology is adopted, the UE will conduct the retransmission only when no Node B in all the activated sets can correctly decode the data. Otherwise, the UE will not execute the retransmission as long as there is one ACK. Adopting macro diversity brings remarkable performance gain, effectively improves throughput, and reduces the retransmission times.

Macro Diversity InfluenceMacro Diversity Influence

CC, SHO (2 links), PA 3kmph, 144kbps, 0dB imb

0

50

100

150

-22 -20 -18 -16 -14 -12 -10 -8 -6 -4 -2Total received Ec/No in the active set [dB]

Thro

ughp

ut [k

bps]

w/ divw/o div

Throughput comparison under PA 3km/h & no soft handover

26

HSUPA cell performance analysis

HSUPA cell throughput demonstrates the function relationship between the average RoT of the cell and the system throughput. Besides being influenced by such factors as the UE quantity, the geographical position where the UE is located and the wireless propagation condition, UE data transmission request, and the uplink interferences of the cells around it, it is also influenced by different wireless and packet scheduling polices and scheduling algorithm. The fairness curve refers to the density accumulation distribution function of the normalization of user throughput by the average throughput of each user, and it reflects the scheduling fairness. The service delay includes the packet call delay and packet delay. The packet call delay refers to the time period between two consecutive packet transmission requests. For the FTP user, the packet call delay refers to the time the FTP uploads the file. The packet delay refers to the time necessary for the reception of the packet message at Node B. RoT overload ratio reflects the ratio of RoT when it exceeds a certain designated RoTthreshold value

HSUPA cell performance analysis is evaluated in the following aspects: The

average throughput of cell, average throughput of a single user, UE

scheduling fairness, service delay and RoT overload rate

Influence of 2 ms TTI on system performance

Comparison of 2ms and 10ms Cell Throughput- Mixed Channel

In HSUPA, the shorter frame structure whose TTI is 2ms is adopted. The shorter frame structure can increase the retransmission times of Layer 1 within the designated time, thereby improving the link efficiency and throughput. Corresponding to the same physical layer delay, the shorter frame structure can effectively lower the delay of the upper-layer transmission

2ms vs. 10ms, mixed channel, PF

0

10

20

30

40

3 3.5 4 4.5 5 5.5 6 6.5Avg. RoT (dB)

Thro

ughp

ut G

ain

(%)

Packet Delay for FTP Users

0

5

10

15

20

25

30

35

3.5 4 4.5 5 5.5 6 6.5

Pack

et D

elay

[s]

Average RoT [dB]TTI=2ms TTI=10ms

Average Packet Delay for FTP Users

Packet Delay for Video Users

00.20.40.60.8

11.21.41.61.8

3.5 4 4.5 5 5.5 6 6.5

Pack

et D

elay

[s]

Average RoT [dB]TTI=2ms TTI=10ms

Average Packet Delay for Video Users

27

Influence of HARQ on system performance

Influence of HARQ on Cell Throughput

We conduct the simulated analysis on the influence of HARQ on the average throughput of the cell when HARQ is on and when it is off. It can be seen that due to the adoption of HARQ and the soft combining technology, the link spectrum efficiency is improved, and the cell throughput is improved by at least 200kpbs. This corresponds to the improvement of HARQ to link performance.

Influence of Soft Handover on System Performance

Influence of Soft Handover on Cell Throughput

We analyze, via simulation, the influence on the average throughput of the cell in the system when there has soft handover (includes softer handover) and when there is no soft handover. It can be seen that due to the adoption of soft handover technology, the link diversity gain is generated, and the cell throughput is improved by at least 120 kpbs.

28

2009-8-10





Content

Radio Communication Technology Development Overview

The radio communication development process from 2G, 3G to 3.9G, is that of developing from mobile voice service to high speed data service.

Nowadays the radio communication technology is evolved to 3.5G, to WCDMA, it can provide commercial R5 version and trial R6 version.

The R7/HSPA+ and R8/LTE standards are being consummated by 3GPP, it is forecasted that the R7 will be frozen in 2007, R8 will be frozen in 2008.

To the development of radio communication technology, more attention should be paid to the requirement of operators – the development target of system from NGMN group

29

Radio Communication Technology Evolution

2G 2.5G 3G 3.5G 3.75G 3.9G2. 75G

GSM WCDMAR99GPRS

EDGE

HSDPA HSUPA

HSPA+

LTE

IS-95 CDMA20001X EV-DO

CDMA2000 1X

EV-DORev. A

EV-DORev. B AIE

CDMA20001X EV-DV

WCDMA Technology Evolution Roadmap

GSMGPRS/EDGE

GSMGPRS/EDGE

3GR99

3GR99

3G+HSDPADownlink Enhanced

3G+HSDPADownlink Enhanced

3GHSDPA/HSUPA

Downlink/Uplink Enhanced

3GHSDPA/HSUPA

Downlink/Uplink Enhanced

GSM(GPRS/EDGE)GSM(GPRS/EDGE)3G3G

Enhanced UMTSEnhanced UMTSOptimized UMTSOptimized UMTS

NGMNNGMN

NGMN（LTE,…）Broadband radio

IP based widebandPeer to Peer

NGMN（LTE,…）Broadband radio

IP based widebandPeer to Peer

2002-3 2003-4 2005-6 2007-9 After 2009Year

Downlink Throughput

64-144kbps 64-384kbps 384kbps-4Mbps 384kbps-7Mbps 20-50Mbps

wr_bt10_e1_1 hsupa principle 59.pdf

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