umts hspa datatransmission performance improvement

8/12/2019 UMTS HSPA DataTransmission Performance Improvement

http://slidepdf.com/reader/full/umts-hspa-datatransmission-performance-improvement 1/43

HUAWEI TECHNOLOGIES CO., LTD.

www.huawei.com

Huawei Confidential

Security Level:2014/2/25

HSPA Data Transmission

Performance Improvement



HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential

HSDPA性能研究与华为解决方案汇报

HSDPA Basic Concepts and Process of Identifying

Data Transmission Problems

HSUPA Basic Concepts and Process of Identifying





Basic Concepts — Protocol Structure of HSDPA User Plane

The data transmission protocol layers consist of the physical layer, MAC layers (MAC-hs/ehs

layer and MAC-d layer), RLC layer, PDCP layer, TCP/IP layer, and application layer. Figure 2-1 shows

the involved NEs and the relationships among layers.

On the RAN side (excluding the UE), the physical layer, MAC layer, and RLC layer are involved.

The TCP/IP layer is adjacent to the PDCP layer and the RLC layer. Therefore, the TCP/IP layer may

also be affected by the RAN in some scenarios

FTP servers, streaming

servers, and websites.

PDCP Packet Data Convergence Protocol




Basic Concepts — Data Frame Structure of HSDPA User Plane Protocol

The rate at each layer is classified into the PDU rate and the SDU rate.

The PDU rate includes the overhead of the current layer, whereas the SDU rate does not include the

overhead of the current layer.

Therefore, the SDU rate of a layer equals to the PDU rate of the upper layer.

RLC RLC RLC RLC RLC RLC

RLC SDU

PayloadRLCHeader

MAC-d

MAC-c

MAC-d

MAC-ehs

Iub-FP Iub-FP Iub-FP

PayloadRLCHeader

PayloadRLC

Header

U-RNTI

PayloadRLCHeader

U-RNTIMAC-ehsHeader

(s)RBs for UE1 (s)RBs for UE2 PDU structure




Basic Concepts —CQI Report Principles

The UE measures the Ec/No of the Common Pilot Channel (CPICH) and adds aMeasurement Power Offset (MPO) as the Ec/No estimation value of the HS-PDSCH.

That is, the UE assumes that the NodeB transmits the HS-PDSCH according to CPICHPower + MPO.

Then, add the SF gain 10 * log16 to obtain the SNR of the HS-PDSCH.

SNR HS-PDSCH = HS-PDSCH Ec/No + SF gain 10 * log16

HS-PDSCH Ec/No (estimation value) = Ec/No cpich + MPO




The CQI is obtained according to the relationship between the SNR and CQI of the

simulated HS-PDSCH.

Generally, the difference between the CQI and SNR is a constant (4 or 4.5 dB).

CQI formula (for the HSDPA excluding 64QAM) :

The previous formula shows that CQI increase by 1 when SNR HS-PDSCH increase by 1.

With 64QAM: when the CQI is greater than 25, CQI increases by 1 when SNR increases by 2 dB.

In this case:

Basic Concepts —CQI Report Principles

CQI = SNRcpich + MPO + 4.5 if CQI <= 25

or CQI = 25 + (SNRcpich + MPO + 4.5 - 25)/2 if CQI > 25

CQI = CPICH Ec/No + MPO + 10 * log16 + 4.5

= SNRcpich + MPO + 4.5

= SNRhs-pdsch (based on assumed power) + 4.5 (depending on the UE implementation)

MPO = min(13, Pcell-Pcpich - MPO constant) dB The MPO constant is 2.5 by default.




1.终端能力

HS-DSCH category

Maximum

number of HS-

DSCH codes

received

Minimum

inter-TTI

interval

Maximum number of

bits of an HS-DSCH

transport block

received within

an HS-DSCH TTI

Supported modulations

without MIMO

operation

or dual cell operation

Supported

modulations with

MIMO operation

and without dual

cell operation

Supported

modulations

with dual cell

operation

Category 1 5 3 7298

QPSK, 16QAM

Not applicable

(MIMO not

supported)

Not applicable (dual

cell operation not

supported)

Category 2 5 3 7298

Category 3 5 2 7298

Category 4 5 2 7298

Category 5 5 1 7298

Category 6 5 1 7298

Category 7 10 1 14411

Category 8 10 1 14411

Category 9 15 1 20251

Category 10 15 1 27952

Category 11 5 2 3630QPSK

Category 12 5 1 3630

Category 13 15 1 35280QPSK, 16QAM, 64QAM

Category 14 15 1 42192

Category 15 15 1 23370QPSK, 16QAM

Category 16 15 1 27952

Category 17 15 135280 QPSK, 16QAM, 64QAM –

23370 – QPSK, 16QAM

Category 18 15 142192 QPSK, 16QAM, 64QAM –

27952 – QPSK, 16QAM

Category 19 15 1 35280QPSK, 16QAM, 64QAM

Category 20 15 1 42192

Category 21 15 1 23370

- -

QPSK, 16QAM

Category 22 15 1 27952

Category 23 15 1 35280

QPSK, 16QAM,64QAMCategory 24 15 1 42192

Basic Concepts — UE Capabilities




The code assignment algorithm is involved in both RNC and NodeB.

RNC:Manual assignment : set the number of codes to be assigned.

Automatic assignment : set the maximum number of codes and minimum number of

codes to be assigned.

NodeB: Enable or disable the NodeB dynamic code function.

We will introduce different combinations of the two algorithms. The number of channels

used by the cell is set by default (four HS-SCCHs with HSUPA activated):

• Manually assign five codes on the RNC

•

Disable the dynamic codes on the NodeB :=> The HS-DSCH uses a maximum of 5 SF16 and a minimum of 5 SF16.

• Enable the dynamic codes on the NodeB:

=> The HS-DSCH uses a maximum of 14 SF16 and a minimum of 5 SF16

Basic Concepts— Code Assignment (1/3)




Basic Concepts — Code Assignment (2/3)

• Automatically assign a maximum of ten codes and a minimum of five codes on the RNC

• Disable the dynamic does on the NodeB:

=> The HS-DSCH uses a maximum of 10 SF16 and a minimum of 5 SF16.

• Enablethe dynamic does on the NodeB:

=> The HS-DSCH uses a maximum of 14 SF16 and a minimum of 5 SF16.

Over one SF16 codes are used by the Common Control Channels

=> maximum of 14 SF16 can be used for HSDPA

• The policy of RNC manual assignment + NodeB dynamic code enabled is

recommended for the existing network.

• RNC automatic assignment + NodeB dynamic code disabled is recommended if

networks do not support the NodeB dynamic codes.




To ensure that 15 codes can be used by the accessed DPA user, you need to modify the

configurations of the channels (Eg disable HSUPA, only 2 HS-SCCHs in one TTI..)

SRB over DCH : Each accessed HSDPA user consumes an associated DPCCH using one SF256SRB over HSDPA : F-DPCH is multiplexed by all users => save codes

Basic Concepts — Code Assignment (3/3)

Default configuration for codes

usage by common channels in the

• The CCH uses one SF32,

• Four HS-SCCHs, each one use one

SF128 => one SF32,

• The E-RGCH and E-HICH

multiplexes one SF128,

• The E-AGCH uses one SF256.




Basic Concepts — EL2 Principles (2/3)

64QAM, MIMO, 64QAM+MIMO, and DC+64QAM technologies are introduced in R8.

The theoretical peak rate of service data transmission can reach 21.6 Mbit/s, 28.8

Mbit/s, and 43.2 Mbit/s respectively.

• If the RLC PDU size is too large, no complete RLC PDU can be correctly transmitted

to the UE when the channel quality is poor; therefore, normal data transmission cannot

be performed and the coverage is reduced.

• If the RLC PDU size is too small and the RLC window size is increased to improve the

data transmission rate, many RLC PDUs are multiplexed in one MAC-hs PDU when the

user channel quality is good; therefore, much redundant information is brought in the

RLC PDU data heads, and the data transmission efficiency of the air interface is

reduced.

To fully match the data transmission capability of the air interface, improve the data

transmission efficiency, the L2 enhancement is introduced.




The L2 enhancement mainly affects RLC layer, MAC layer, and user plane FP data transmission of Iub

interface on the RNC.

• The variable PDU size of downlink AM is introduced at the RLC layer.

• The MAC-ehs is introduced at the MAC layer.

•The 64QAM, MIMO, and DC-HSDPA features must be supported by EL2 enhancement.

Basic Concepts — EL2 Principles (3/3)

The maximum RLC PDU is set to 302

bytes (2416 bits) in EL2 by default




Basic Concepts — Theoretical Rates of Layers (1/2)

Relationships among the throughput of layers :

• TCP/IP layer: Data packets at this layer are received from the application layer. The

TCP/IP layer matches data packets based on the MTU (Maximum Transfer Unit ) size.

Generally, the MTU size is 1,500 bytes, which is equal to 12,000 bits. The header

overhead of 40 bytes (320 bits) is added to each MTU.

•

PDCP layer: Data transmission is considered as transparent transmission at this layer,and therefore no overhead is added.

• RLC layer: This layer matches data packets of the PDCP layer based on the RLC SDU

size. The overhead of 16 bits is added to each SDU to form an RLC PDU. Then, the RLC

PDU is transmitted to the MAC-d layer.

• MAC-d layer:Data transmission is considered as transparent transmission at this layer,

and therefore no overhead is added.




Basic Concepts — Calculation of Theoretical Rates (1/4)

Example for UE CAT14 ：

CAT14 supports EL2 and 64QAM (MAC-ehs entity)

The maximum TBS used in CAT14 is 42192 bits

1) The maximum rate of the MAC-hs layer is: 42192 bits /2 ms = 21.096 Mbit/s

2) At the RLC layer (EL2) :

- The maximum RLC PDU is set to 302 bytes (2416 bits) in EL2 by default

- If 42192 (minus fixed 8 bits overhead for EL2) => 42184 bits

- Nb of RLC PDU (Mac-ehs SDU) => int (42184/2416) = 17 PDU

- 17 PDUs of 2416 bits can be carried and 16-bit overheads are introduced (EL2).

42184 bits – (2416 bits * 17) – (16 * 17) = 840 bits.

- After subtracting the introduced 16-bit overhead, the PDU that can be carried is 824 bits.

The maximum PDU rate at the RLC layer is: (2416 bits * 17 + 824 bits)/2 ms = 20.95 Mbit/s

Maximum number of bits of an HS-DSCHtransport block received within

an HS-DSCH TTI




Downlink UE Throughput During RNC Real-Time Performance Tracing

Real-time performance tracing from RNC give the Downlink UE throughput at the MAC-d layer(that is, the SDU rate at the MAC-hs layer) or the PDU rate at the RLC layer.

Downlink Throughput Displayed in DU Meter (monitor TCP IP throughout)

Downlink throughput displayed in DU meter can be considered as the SDU rate at the RLC rate.

Basic Concepts — Calculated of Theoretical Rates (3/4)




IBLER / SBLER/ RBLER

• The 1st BLER is called initial BLER (IBLER).

• SBLER indicates the sum BLER, regardless of the initial TBS transmission or HARQ retransmission.

• Residual BLER (RBLER) indicates the BLERs for TBs still incorrectly transmitted after all the HARQ

retransmissions at the MAC-hs layer.

Example:

The maximum number of HARQ retransmission is 4, three TBSs must be transmitted:• The first TB is correctly transmitted during the initial transmission.

• The second TBS is retransmitted correctly after an initial transmission.

• The third TB is retransmitted incorrectly for four times.

• IBLER, the initial transmission of the first TB is successful and the initial transmissions of the second and

third TBs fail. Therefore, IBLER = 2/3 = 66.67%.

•

SBLER, the first TBS is transmitted only once with zero transmission failure. The second TBS istransmitted twice with one transmission failure. The third TBS is transmitted five times with transmission

failure five times. Therefore, SBLER = (0 + 1 + 5) /(1+2+5) = 75%.

• RBLER, the first TB is correctly transmitted during the initial transmission. The second TB is retransmitted

correctly after an initial transmission. The third TB fails to be retransmitted for four times. Therefore,

RBLER = 1/3 = 33.33%.

Basic Concepts — Calculation of Theoretical Rates (4/4)




Process of identifying stationary test-based HSDPA

data transmission problemsIdentify stationary

test-based HSDPA data

transmission problems

END

NCheck and

clear alarms

3.2.3

Check downlink

power resources

3.2.8

Is the problem

identified?

Is the problemidentified?

Y

N

N

Check cells’

HSDPA status

3.2.4

Check access

signaling

3.2.5

Check

licenses

3.2.6

Check the

DCCC setting

3.2.7

Check

downlink code

resources

3.2.9

Check radio

quality

3.2.11

Check packetloss on the Iub

interface

3.2.15

3.2.12

Collect data andreport problems

3.2.19

Is the problem identified?

Y

Contact CN

engineers to locate

the fault, which

must be supported

by the RAN

Y

N

Dial-up succeeds while

transmission fails

Identify who

transmission fails

3.2.1

Can data transmission be started

Is data transmission OK?

Y

Y

N

N

NY

RAN problems?

Replace the UE or

driver program

Y

N

Y

Is the problemidentified?

Check the bandwidth on the lub interface

3.2.13

Check RAN problems3.2.2

Check bandwidth

on the IU-PSinterface

3.2.14

Check packet

losses on the IU-

PS interface andTCP mechanism

3.2.16

Check andisolate UE faults

3.2.17

Check CPU

usage of laptops

3.2.18

Y

N

Check the number of

online users in a cell

3.2.10

Check if RLC downlink

window is full




Process of identifying Drive Test test-based HSDPA

data transmission problemsIdentify DT test-based HSDPA

data transmission problems

Does calldrop or handover failure (or

not timely) exist

Does abnormal

point exist (with high CQI but

low throughput)

Is the problem solved END

Check and clearalarms, especially,cell-level alarms

3.2.4

Check cells’ HSDPA status

3.2.5

Check the license,especially the

NodeB-level license

3.2.7

Check downlinkcode resources

in each cell

3.2.11

Check the bandwidthof the lub interface on

each NodeB

3.2.14

Collect data and report

problems

3.2.19

Y

Y

N

Perform static test of data transmission on a near point,

check whether anyproblem exists

Handle with the

problem

Check downlinkpower resources

in each cell

3.2.10

Handle with the

problem

Handle with the

problem

Perform DT in idle

period (with few

online users)

Optimize RF coverage

and improve the

average CQI

Y

Is the problem solved

N

N

Y

N

Y

N




Flowchart of analyzing HSDPA cell performance problems

Y

Does the

average single-user throughput reach

the required BER on the airinterface?

The item cannot be

evaluated at present.

Identify HSDPA

cell performanceproblems

Is the power

usage high?YIs the CQI

poor?Y

Optimize the

coverage

There is an

optimization scheme.

Are there

many UEs?

N

Perform

expansionY

Is the Iub

transmission usage

high?

Is the RLC

retransmission ratio

high

N

YPerform Iub

expansion

Y

Is the

transmission quality of

the Iub path poor?

Optimize the

transmissionY

N

Is the residual

BER on the air interfacehigh?

Is the code usage

high?

N

Check power

control parameters Y

N

UE problems

YPerform

expansion

N

Is upper-layer

data insufficient?

Other problemsN

Global or upper-

layer problemsY

END

N

N

Is the BER

on the air interface

high?

N

Y

Does the theoretical cell rate

meet the requirement?Y

N

END




Analysis on HSDPA cell performance problemsStep Evaluation Item Evaluation Result and Handling Suggestion

High Low

(1)Bit error rate (BER) on the airinterface in the cell Optimize the coverage. Go to step (2).

(2)

Power usage of the cell

Perform the following operations based on the CQI:

If the CQI is poor, optimize the coverage.

If the CQI is normal, add carriers.

Go to step (3).

(3)Usage of the Iub transmission

bandwidthExpand the Iub transmission bandwidth. Go to step (4).

(4)

RLC retransmission rate

Perform the following operations based on the IP pathtransmission quality on the Iub interface:

If the transmission quality is poor, optimizetransmission.

If the transmission quality is normal, check the residual bit errors on the air interface. For the cells with many bit errors on the air interface, check power control parameters.

Go to step (5).

(5)

Code resource usage Add code resources.

Check whether thetheoretical rate of the cellmeets the requirement. Ifthe theoretical rate meetsthe requirement, the upper-layer data sources areinsufficient.




HSDPA性能研究与华为解决方案汇报

HSDPA Basic Concepts and Process of Identifying


HSUPA Basic Concepts and Process of IdentifyingData Transmission Problems




Basic Concepts — Protocol Structure of HSUPA User Plane

Figure below shows the protocol structure of HSUPA data services. Different from the R99

user plane, a MAC entity MAC-e/es is added at the MAC-d layer on the HSUPA user plane.

PHY PHY

EDCH FP EDCH FP

Iub UE NodeB Uu

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




Basic Concepts — Data Frame Structure of HSUPA User Plane Protocol

MAC-es header overhead:

• TSN : Transmission Sequence Number (6 bits)

MAC-e header overhead:

• DDI : Data Description Indicator (6 bits)• N: Number of Mac-d PDU in a logical channel (6 bits)

• SI system information : SI bits and padding bits in the end

MAC-d Flows

MAC-es PDUMAC-e header

DCCH DTCH DTCH

HARQprocesses

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 flowid => DDI

DATA DATA

MAC-d PDU:

DDI

Header

MAC-es/e

NumberingMAC-es PDU: TSN DATA DATANumbering Numbering

1.Simplified architecture showing MAC inter-working in UE. The left part shows the functional split while the right part shows PDU construction

MAC-d PDU MAC-d PDU MAC-d PDU

MAC-es SDUMAC-es SDUTSN1 N1DDI1 MAC-es SDU

MAC-d PDUs coming from one Logical Channel

N1 MAC-es SDUs of size and LCh indicated by DDI1

MAC-es PDU1

DDI1 N1 DDI2 N2

DDI1 N1 DDI2 N2 DDIn Nn DDI0(Opt)

MAC-es PDU1 MAC-es PDU2 MAC-es PDUn

MAC-es PDU2 MAC-es PDU1 DDIn Nn MAC-es PDUn

MAC-e PDU

SI(Opt)

Padding(Opt)




Basic Concepts — Factors Affecting the Uplink Load

1.Simplified architecture showing MAC inter-working in UE. The left part shows the functional split while the right part shows PDU construction

Number of Users in the Cell

• Check the number of users in the cell in real time on the RNC LMT.

The uplink load is shared by all users. When the number of users increases, the available load of each

user is reduced, therefore affecting the throughput.

On the other hand, the HSUPA scheduling can only control the load of the HSUPA scheduling users.

If many non-HSUPA scheduling users exist in the cell, the available load of the HSUPA scheduling

user is affected, therefore affecting the actual rate of the HSUPA scheduling users.

• If the actual load is less than or equal to 75 , the HSUPA user throughput should be

higher than to MAX(GBR, 1 RLC PDU rate).

• If the actual load is greater than 75 and less than 95 , the HSUPA user throughput is

equal or les than MAX(GBR, 1 RLC PDU rate).

• If the actual load is greater than 95 , the HSUPA user throughput is hard to reach the

GBR but may meet 1 RLC PDU rate.




Basic Concepts — Factors Affecting the Uplink Load

External Interference :

External interference involves neighboring interference and foreign interference

If a burst of interference occurs, the load of the cell rises instantly causing the throughput fluctuation of

HSUPA users.

=> Check the RTWP of the cell when no user exists or identify the problem by using frequency

sweep.




Basic Concepts — Uplink CE Consumption Rules

Direction Rate

(kbit/s) SF

Number of CEs

Consumed

Corresponding

Credits Consumed

UL 8 64 1 2

UL 16 64 1 2

UL 32 32 1 2

UL 64 32 1 2

UL 128 16 2 4

UL 144 16 2 4

UL 256 8 4 8

UL 384 4 8 16

UL 608 4 8 16

UL 1450 2SF4 16 32

UL 2048 2SF2 32 64

UL 2890 2SF2 32 64

UL 5760 2SF2+2SF4 48 96




E-DCHCategory

Max. CapabilityCombination

E-DCH TTIMAX EDCHTBS (10ms)

MAX EDCHTBS (2ms)

Max. Data Rate (Mbit/s)

MAC Layer

10 ms TTI

MAC Layer

2 ms TTIAir Interface

Category 1 1 x SF4 10 ms only 7110 0.71 - 0.96

Category 2 2 x SF4 10 ms and 2 ms 14484 14000 1.44484 1.40 1.92


Category 4 2 x SF2 10 ms and 2 ms 20000 289000 2.0 2.89 3.84


Category 6 2 x SF4 + 2 x SF2 10 ms and 2 ms 20000 57400 2.0 5.74 5.76

Category 7 2 x SF4 + 2 xS F2 10 ms and 2 ms 20000 1150000 2.0 11.50 11.52

Category 8 2 x SF4 + 2 xS F2 2 ms 20000 1150000 2.0 11.50 11.52

Category 9 2 x SF4 + 2 xS F2 2 ms 20000 2300000 2.0 23.00 23.04

To support HSUPA, 3GPP TS 25.306 defined nine UE categories. These UEs support different peak

rates at the MAC layer, ranging from 711 kbit/s to 23 Mbit/s.

Basic Concepts calculated of Theoretical Rates




Basic Concepts — calculated of Theoretical Rates

RLC PDU UL throughput :

= Total size of all RLC PDUs transmitted at the RLC layer within a measurement period/ Measurement period

• Total size of all RLC PDUs transmitted at the RLC layer :

- involves the PDUs transmission and retransmission.

- Data transmitted by the MAC-d layer including the header overhead of the

RLC PDU with total size of 16 bits.

• Measurement period : all the time whether data is transmitted or not.

Relationship between the RLC PDU UL throughput and the MAC-e PDU available rate:

RLC PDU UL throughput = MAC-e PDU available rate * (1 - MAC-e PDU header

overhead ratio)




RLC SDU Throughput UL

= Total size of all RLC SDUs transmitted at the RLC layer within a measurement period /Measurement period

• Total size of all RLC SDUs transmitted at the RLC layer :

= Total bits of RLC PDUs – Σ of retransmitted bits and RLC PDU header overhead (16bits in total).

The relationship between the RLC SDU Throughput UL and the RLC PDU Throughput UL :

RLC SDU throughput UL ≈“RLC PDU UL throughput” * “(1 - RLC PDU retransmission rate UL)” * “RLC PDU

header overhead ratio.”

Uplink Throughput involved in RNC Radio Performance Monitoring

MAC SDU rate (the input rate at the MAC layer) also called the RLC PDU rate (the output rate at the RLC layer) involves

the retransmitted data at the RLC layer.

HSUPA CAT3, MAC SDU size = 336 bits:

MAC-d SDU rate = int(14484/336) * 336/10 = 1.4448 Mbit/s

HSUPA CAT6, MAC SDU size = 336 bits:

MAC-d SDU rate = int(11484/336) * 336/2 = 5.712 Mbit/s

Basic Concepts — calculation of Theoretical Rates

MAC-d SDU rate = (TB-Size * Number of TBs) / TTI




Basic Concepts — HSUPA Theoretical Rates of Layers

CAT3：

1) Throughput at the physical layer: (3840000/4) * 2 (SF4) = 1.92 Mbit/s

2) Data rate at the MAC-e layer: Maximum TBS at the MAC-e layer /10 ms

= 14484 * 1000/10 ms = 1.448 Mbit/s

Number of MAC-d PDUs per MAC-e PDU = Maximum TBS at the MAC-e layer (bits) / MAC-d PDU size(bits)

Number of MAC-d PDUs (MAC-d PDU size = 336 bits) = int(14484/336) = 43,

RLC payload rate : CAT3 theoretical rate = (RLC payload size * Number of TBs) / TTI

RLC SDU size = MAC-d PDU - MAC header - RLC header = 336 -16 = 320 bits

CAT3 theoretical rate (MAC-d PDU size is 336 bits) = (320 * 43) /10 = 1.376 Mbit/s.

The MAC SDU rate monitored on the LMT = int(14484/336) * 336/10 = 1.448 Mbit/s.

The maximum throughput at the application layer ≈ the RLC payload rate / (1 + 10% of HARQ retransmission)

= 1.36 Mbit/s




CAT5：

Throughput at the physical layer : (3840000/2) * 2 (SF2) = 3.84 Mbit/sData rate at the MAC-e layer: Maximum TBS at the MAC-e layer * 1000/10 ms => 20000 * 1000/10 = 2 Mbit/s

Number of MAC-d PDUs per MAC-e PDU = Maximum TBS at the MAC-e layer (bits)/MAC-d PDU size (bits)

Number of MAC-d PDUs = int(20000/336) = 59

CAT5 theoretical rate (RLC payload rate) = (RLC payload size * Number of TBs)/TTI

RLC SDU size = MAC-d PDU - MAC header - RLC header = 16 bits

If the MAC-d PDU size is 336 bits, the CAT5 theoretical rate is 59 * 320/10 = 1.888 Mbit/s

The MAC SDU rate monitored on the LMT is: int(20000/336) * 336/10 = 1.9824 Mbit/s.

The maximum throughput at the application layer ≈ the RLC payload rate/(1 + 1% of HARQ retransmission) = 1.87 Mbit/s

CAT6 SRB OVER E-DCH ：

Throughput at the physical layer: (3840000/2) * 2 (SF2) + (3840000/4) * 2 (SF4) = 5.76 Mbit/s

Data rate at the MAC-e layer: Maximum TBS at the MAC-e layer * 1000/2 ms => 11484 * 1000/2 = 5.742 Mbit/s



CAT6 theoretical rate (RLC payload rate) = (RLC payload size * Number of TBs)/TTIRLC SDU size = MAC-d PDU - MAC header - RLC header = 16 bits

If the MAC-d PDU size is 336 bits, the CAT6 theoretical rate is 34 * 320/2 = 5.44 Mbit/s.


The maximum throughput at the application layer ≈ the RLC payload rate/(1 + 10% of HARQ retransmission) = 4.945 Mbit/s





CAT6 SRB OVER DCH ：

Throughput at the physical layer: (3840000/2) * 2 (SF2) = 3.84 Mbit/s

Data rate at the MAC-e layer: Maximum TBS at the MAC-e layer * 1000/2 ms => 5772 * 1000/2 = 2.886 Mbit/s



CAT6 theoretical rate (RLC payload rate) = (RLC payload size * Number of TBs)/TTI

RLC SDU size = MAC-d PDU - MAC header - RLC header = 16 bits

If the MAC-d PDU size is 336 bits, the CAT6 theoretical rate is 17 * 320/2 = 2.72 Mbit/s.


The maximum throughput at the application layer ≈the RLC payload rate/(1 + 10% of HARQ retransmission) = 2.473 Mbit/s


Process of Identifying Stationary Test-Based HSUPA




Process of Identifying Stationary Test-Based HSUPA

Problems Identify stationary test-based HSUPAdata transmission problems

Dial-up succeeds while datatransmission fails

Identify data

transmission failure

3.2.1

Is data transmission OK?

Check and

clear alarms

3.2.4

Check the minSF during the linksetup or re-configuration

3.4.1

Check UE

capabilities

3.4.2

Check cell

capabilities

3.4.3

Check the Assigned rate

of the CN

3.4.4

Check RANparameters

3.4.5

Check theDCCC

algorithm

3.4.7

Y

Is the problem solved?



Is the fault rectified

Y

N

N

Y

END

Y

N

Y

N

Y

Y

Y

N

N

Y

N

Is UE traffic volumerestricted

3.4.8

Is the UE transmissionpower restricted

3.4.7

N

N

Check UE location and outlooppower control

3.4.7

Check the RLClayer

3.4.8

Check uplink loadresources

3.4.9

Check uplink CEresources

3.4.10

Check Iub resources

3.4.11

Collect data and report3.2.19

Is the problemcaused by UE

Is the problemcaused by server or

CN

Replace the UE or driver

Contact CN engineersto locate the fault, which

must be supported by

the RAN

Is the

problem caused by

laptop

Modify the laptop setting

or replace the laptop

Y

Y

Y

N

N

N

Check the TCP layer

and higher layers

3.4.8



P f Id tif i P f M t




Process of Identifying Performance Measurement-

Based HSUPA Data Transmission Problems

END N

Y

N

N

N

Y

NY

N

Y

Others

Is MultiACkabnormal?

The power controlof the control

channel or UE isabnormal.

Otherproblems Differentialcauses

Y

Does the averagesingle-user throughput reach

the cell requirement?

Is the BLER on theair interface high?

The item cannot beevaluated at present.

Evaluation item Identify HSUPA cellperformance problems

Is the uplink load limited?

Are CE resources limited?

Is the residualBLER high?

Is the UE in theUnhappy state?

Y

N

Is the transmitpower of the UE

limited?

Is the RLCretransmission ratio

high?

Is the Iubtransmission quality

poor?

Out-loop power controlproblems

N

N

Y

The uplink RTWP ishigh or the UE is faraway from the cell

center.

YOptimize the

transmission quality

Power controlparameters are

incorrect.

Is the RTWP limited?

Y Are data sources

insufficient?

Y

N

Perform expansion,use dynamic CEs, and

optimize the GBR

Y

Are Iubresourceslimited?

N

Expand the Iubtransmissionbandwidth

Y



Thank youwww.huawei.com




Probe:

Scheduled rate = Total size of all TBs received by the MAC-hs layer within a measurement period/Total duration for scheduling

TBs within a measurement period

The total size of all TBs received at the MAC-hs layer within a measurement period: involves the TBs that are correctly andincorrectly received.

Total duration for scheduling TBs within a measurement period: includes only the time when TBs are received. For example,

within a measurement period of 100 subframes (200 ms), if only 50 subframes contain data, the duration for receiving TBs with

data within a measurement period is 100 ms.

Served rate = Total size of all TBs received by the MAC-hs layer within a measurement period/Measurement period

Total size of all TBs received at the MAC-hs layer within a measurement period involves the TBs that are correctly and

incorrectly received.

Measurement period indicates all the time when TBs are received and not received.

The relationship between the served rate and the scheduled rate is as follows:

Served Rate = Scheduled Rate * HS - SCCH success rate

HS-SCCH success rate = Total duration for receiving TBs within a measurement period /Measurement period. The HS-SCCH

success rate indicates the scheduling probability.

MAC layer rate = Total size of TBs correctly received at the MAC-hs layer within a measurement period/Measurement period

Total size of TBs correctly received at the MAC-hs layer within a measurement period only involves the TBs that are correctly

received.

Measurement period indicates all the time when TBs are received and not received.

The relationship between the MAC layer rate and the served rate is as follows:

MAC layer rate = Served rate * (1 - SBLER)

SBLER = Total size of TBs incorrectly received within a measurement period/Total size of all TBs received within a

measurement period. The SBLER indicates the BLER of TBs.

To reflect user experience more approximately, the rate at the MAC layer is usually used.

Basic Concepts—calculated of Theoretical Rates



Basic Concepts——calculated of Theoretical Rates

Probe

MAC-e PDU non-DTX rate = Total size of all TBs during non-DTXs/(Number of non-DTXs * TTI)

Measurement period: The measurement period for a single log packet is 20 TTIs.

The MAC-e PDU non-DTX rate is the actual MAC-e rate excluding the TB transmission during DTXs but including TBretransmission；

Total size of all TBs during non-DTXs involves the TBs that are initially transmitted and retransmitted.

"Number of non-DTXs * TTI" indicates only the duration in which TBs are transmitted. For example, within a measurement period

of 100 subframes (200 ms), if only 50 subframes contain data, the "number of non-DTXs * TTI" is 100 ms.

MAC-e PDU served rate = Total size of all TBs during non-DTXs/(NUM_SAMPLES * TTI)

The MAC-e PDU served rate is the MAC-e service rate including the TB transmission during DTXs and TB retransmission.

Total size of all TBs during non-DTXs involves the TBs that are initially transmitted and retransmitted.

NUM_SAMPLES * TTI indicates duration in which TBs are transmitted and not transmitted. For example, within a measurement

period with 100 subframes (200 ms), if only 50 subframes contain data. However, the "NUM_SAMPLES * TTI" is still 200 ms.

The relationship between the MAC-e PDU served rate and the MAC-e PUD non-DTX rate is as follows:

Served rate = MAC-e PDU non-DTX rate * Non-DTX probability

Non-DTX probability = Number of non-DTXs/NUM_SAMPLES * 100%

MAC-e PDU available rate = Total size of all TBs during non-DTXs and when COMB_HIGH is ACK and

ACK_NS/(NUM_SAMPLES * TTI)

Total size of all TBs during non-DTXs and when COMB_HIGH is ACK and ACK_NS" involves only the TBs that are correctlytransmitted.

NUM_SAMPLES * TTI indicates all the time whether data is transmitted or not.

The relationship between the MAC-e PDU available rate and the MAC-e PUD served rate is as follows:

MAC-e PDU available rate ≈"MAC-e PDU served rate" * (1 - SBLER)

SBLER = (Number of non-DTXs – Number of ACKs or ACK_NSs)/Number of non-DTXs * 100%

umts hspa datatransmission performance improvement

Documents