Uplink Incremental Redundancy

8/8/2019 Uplink Incremental Redundancy

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BR9.0BR9.0 OrderOrder EnablingEnabling

Uplink Incremental RedundancyUplink Incremental RedundancySales Feature No.Sales Feature No. SF10501SF10501, FRS No., FRS No. 459459

Grzegorz LehGrzegorz Lehmann, Network Engineering GERAN


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Siemens G. Lehmann, SN SDC NA B1, Feb 14-16 3

Uplink Incremental RedundancyUplink Incremental Redundancy

BenefitsBenefits

Link Adaptation is more relaxed LA switches do not happen as

frequently as before after UL&IR implementation

UL IR increases the efficiency of Link Quality Control (LQC) the

combination of LA&IR algorithm allows the network to operate veryclose to optimum condition

Increased probability of correct reception

The overall EDGE/EGPRS performance gain can be noticed of

roughly 2-4dB over the C/I range from 5dB to 25dB

No IR IR


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Configuration aspectsConfiguration aspects

UL IR is enabled / disabled on cell basis

Two modes supported in the cell: pure LA mode and the LA&IR

mode

Sufficient BTS memory available for UL IR on each transceiver

required

Siemens ECU&FCU optimum UL IR behaviour close to

infinite memory case


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Technical descriptionTechnical description

Incremental Redundancy Link Quality Control algorithm designed

for UL & DL supplement for Link Adaptation

IR the enhancement of the physical layer performance for the

acknowledged RLC mode of EGPRS IR EGPRS specific implementation of type II hybrid ARQ

transmission scheme

UL IR performed by BTS 'autonomously'

UL IR needs a communication between Channel Coding Unit

(located in the BTS) and PCU (located in BSC)

Inband signaling between BSC/PCU and BTS via the

concatenated PCU frames shortened TLLI values


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Technical descriptionTechnical description

Data packets are resent from the MS in

UL with the same MCS but different

puncturing scheme

The PS is changed cyclically: P1->P2->P1->P2->... for MCS1,

MCS2, MCS5, MCS6

P1->P2->P3->P1->P2->P3-

>P1...for MCS3, MCS4, MCS7,

MCS8, MCS9

Equalizer

Softbits,BSN,TFI,shTLLI

IR Bit

set?

yes

no

Decode Header

RAM

DataPCU-frame

With filling pattern

Hashing

-Store new data

-Load old data

Normal decoding

Joint Decoding(*)

Block

ok ?

yes

Delete block data

no

idle PCU-frame

if Header Error

Error ?

yes

no

DataPCU-frame

With payload(*)In case of first t ime block reception: normal decoding else joint decoding

As long as the original block can't be reconstructedAs long as memory is availableAs long as the delay is acceptable

Blocks are stored and used for joint decoding .

When IR was finally successful all these blockshave to be removed from the memory.


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SW featuresSW features -- InterdependenciesInterdependencies

UL IR enhancement of the already introduced GPRS/EGPRS Link

Adaptation strategy Features supporting GPRS/EGPRS

functionality has to be enabled:

FRS 0431: New EDGE/GPRS PCU Frames Support of theinband signaling between BTS and BSC/PCU

FRS 0429: FAAS: flexible Abis allocation strategy

Support of GPRS/EGPRS higher throughputs on Abis interface

FRS 0419: Support of CS-3/CS-4 Contains the enabling

parameters for the enabling of CS to be used for the linkadaptation of GPRS


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SW featuresSW features -- InterdependenciesInterdependencies

UL IR enhancement of the already introduced GPRS/EGPRS Link

Adaptation strategy Features supporting GPRS/EGPRS

functionality has to be enabled:

FRS 0516: GPRS resource management BLER andcurrent MCS are used to evaluate the radio resources for each

mobile

FRS 0419: BR7.0 Support of CS-3/CS-4 Enabling of

GPRS CS-3/CS-4

FRS 454: BR7.0 EDGE impacts on O&M Parametersrelated to the enabling of EGPRS

FRS 481: BR7.0 EGPRS radio aspects Radio aspects for

EGPRS


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Customer BenefitCustomer Benefit

Higher data rates in UL direction

Certain UL throughputs available in higher cell range

HW requirementsHW requirements

The BSC must be equipped with PPXU cards for support of UL IR

BTS must be EDGE capable

Since both LQC modes: LA and LA&IR are mandatory forGPRS/EGPRS capable MSs, UL IR is supported as well


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Database parametersDatabase parameters

Parameter acronym

(long name)

Validity

rangeObject Default Description

EULINCRED(enableUplinkIncrementalRedundancy)

True /False

PTPPKF FalseThis parameter is used to enable/disableUL IRCREATE, SET and GET commands

TSASHOTLLI

(timerSameShortTLLI) 0, 1, 2,...20 sec PTPPKF 5 sec

This parameter is used by IR memory

management function (BSC timer). If for aspecific TBF (indicated by shTLLI and TFI)

a block is received, the time period to the

last received block of the same TBF shallbe checked (FN-LastULBlock TBFn). If that

last block was e.g. > 5 seconds ago, then

all block copies of the TBF shall be deleted

CREATE, SET and GET commands


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Database parametersDatabase parameters

BR8.0 attribute name BR9.0 attribute name

enMcsFamAMcs1UplinkWoutIncrRed8PskEMFA1UNIR8PSK

enMcsFamAMcs1Uplink8Psk EMFA1UL8PSK

enMcsFamApMcs1UplinkWoutIncrRed8PskEMFAP1UNIR8PSK

enMcsFamApMcs1Uplink8Psk EMFAP1UL8PSK

enMcsFamBMcs1UplinkWoutIncRed8Psk EMFB1UNIR8PSK enMcsFamBMcs1Uplink8Psk EMFB1UL8PSK

enMcsFamCUplinkWoutIncRed8PskEMFCUNIR8PSK

enMcsFamCUplink8PskEMFCUL8PSK

enMcsFamGmskUplinkWoutIncRed8Psk EMFGUNIR8PSK enMcsFamGmskUplink8Psk EMFGUL8PSK

enMcsFamCUplinkWoutIncrRedGsmk EMFCUNIRGMSK enMcsFamCUplinkGsmk EMFCULGMSK

enMcsFamGmskUplinkWoutIncrRedGsmk EMFGUNIRGMSK enMcsFamGmskUplinkGsmk EMFGULGMSK

initialMcsUplinkWoutIncrRed8psk IMCSULNIR8PSK initialMcsUplink8psk IMCSUL8PSK

initialMcsUplinkWoutIncrRedGmsk IMCSULNIRGMSK initialMcsUplinkGmsk IMCSULGMSK

New names for already existed attributes responsible for the

enabling of MCS families for UL data transfer without IR


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Uplink Incremental Redundancy