Extended UL TBF Mode Ed5

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All rights reserved 2005, Alcatel

Extended Uplink TBF Mode

August2005


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All rights reserved 2005, AlcatelExtended UL TBF mode / July2005

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EXTENDED UPLINK TBF MODEIntroduction

The aim of this feature is to extend the duration of the UL TBF in order:

To quickly restart data transmission in UL if higher layers in the MS delivernew data, without having to re-establish a new UL TBF, after the countdownprocedure has started

To maintain the UL TBF established, some time after the last block (CV=0)has been acknowledged by the network

This feature allows improving access time to the GPRS network. It alsoimproves the throughput in some cases.

The feature is described in 3GPP TS 44.060 - V4.18.0. It applies for R4 MS


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The BSS shall:

1. Enable or disable the Extended uplink TBF mode through an O&M parameter,EN_EXTENDED_UL_TBF . And configure an inactivity period as duration of extended uplinkTBF mode, T_MAX_EXTENDED_UL.

2. Indicate to MS that the network supports the extended uplink TBF mode. The MS is aware ofthe BSS capability by the NW_EXT_UTBF parameter that is broadcast on either BCCH(SI13)or PBCCH (PSI1). So the MS is always aware of the BSS capability before establishingan Uplink TBF. On the contrary the BSS does not always know the MS capability when the

first Uplink TBF is established at the beginning of a session.3. Detect whether or not a given MS supports the Extended Uplink TBF Mode. The MS radio

access capability is received at downlink TBF establishment in the first downlink PDU.

In case of cell reselection for an uplink transfer, some time TBF may elapse before aDownlink PDU is received. Radio Access Capability Update procedure is used to obtain theinformation.

4. Apply the Normal release mode (with delayed final PUAN) if the MS does not support theExtended Uplink TBF Mode or if the BSS does not know MS capability.

Switch to Extended Uplink TBF Mode when a MS is detected to support the feature, whenthe Radio Access Capabilities are received during the UL transfer.

5. Maintain to USF scheduling an uplink TBF during the inactivity period, while the MS has nodata to transmit, and maintain the reception of uplink RLC data block as long as the uplinkTBF is in extended phase.

6. Release the uplink TBF upon timerT_max_extended_UL expiry

EXTENDED UPLINK TBF MODEFunctional description


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Radio Access Capability Update

Enable or disable the Radio Access Capability update on Gb by flag, EN_RA_CAP_UPDATE. Recommend to enable this flag if EN_EXTENDED_UL_TBF is enabledand Radio Access Capability update is supported by SGSN.

At UL TBF establishment, immediately after the contention resolution procedure,the radio access capability update procedure is triggered in the BSS. The BSSrequest an MSs current Radio Access capability and/or its IMSI by sending to anSGSN a RA_CAPABILITY_UPDATE, which includes the TLLI of the MS and aTag. Then starts timer T5_RA_CAPABILITY_UPDATE . In case of the timerexpiry, BSS shall repeat the request up to RA_CAPABILITY_UPDATE_RETRIES times (value = 3).

The SGSN shall respond by sending a RA_CAPABILITY_UPDATE_ACK, whichincludes the TLLI of the MS, the Tag received in the corresponding

RA_CAPABILITY_UPDATE.When the SGSN answers, the MS Radio Access capability is updated and theExtended UL feature can be used if the GERAN Feature Package 1 bit is set.Otherwise, the MS does not support the extended uplink feature.

EXTENDED UPLINK TBF MODEAcquiring MS capability


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EXTENDED UPLINK TBF MODEMS capability is not know at UL TBF establishment (1/2)

If the MS RA capabilities are receivedbefore the T_delayed_Final_PUAN timerexpires and if the MS supports theGERAN Feature Package 1, then theTBF extended mode shall be entered

MS capabilities updated in the BSS

When the BSS receives the information

that the MS supports the extended ULmode, the BSS stops the timerT_delayed_final_PUAN and starts thetimer T_max_extended_UL.

The BSS sends a PUAN, FAI=0,SSN=n+1 and polling, so that the MSswitches to UL TBF extended phase.

USF are scheduled. The MS will repeatonce the last UL block sent, because

SSN = last BSN was sent whenT_delayed_final_PUAN was started.

If the MS has no new data to send, itwill send uplink dummy blocks. If it hasnew data to send, it will transmit newradio data block and increment BSN.

RLCblock,BSN=n,CV=0

MS BSS

PUAN,SSN=n,FA

I=0Start

T_delayed_final_PUAN

USF

PUAN,SSN=n+1,FA

I=0

USF

Extended UL TBF mode supported

stop T_delayed_final_PUAN

enter TBF extended phase

SSN=n+1

USF

USF

T_max_extended_UL


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EXTENDED UPLINK TBF MODEMS capability is not know at UL TBF establishment (2/2)

When T_delayed_final_PUAN is running, the BSS shall not schedule USF to theMS. However MS may received some USF, sent before T_delayed_final_PUANwas started in the BSS, and BSS received RLC block when the timer is alreadystarted in the BSS.

BSS behavior if RLC blocks received while T_delayed_final_PUAN running

RLCblock,BSN=n,CV=2

MS BSS

Start

T_delayed_final_PUAN

RL

Cblock,BSN=n+1,CV=1RLCblock,BSN=n+2,CV=0

RLCblock,BSN=n+3,CV=m

New data

MS radio access

capability NOT known

yet

USF

Data

block

If the MS is a R99, it will repeat the lastBSN for these USF. The BSS discard

this block, but does not count any

protocol error.

If the MS is a R4, it will repeat the last

BSN once and send a few dummy

blocks, or it may try to sent blocks with

BSN>n+2 if it has new data to transfer.Dummy blocks and data blocks,

received by the BSS while

T_delayed_PUAN is running shall be

discarded, but shall not increment any

counter for protocol error.


7/22All rights reserved 2005, AlcatelExtended UL TBF mode / July2005

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If MS support Extended UL TBF mode is known.

Entering the Extended uplink phase

When the MS begins to run out of LLC data, it begins the countdown normally.When the BSS receives the last RLC block (CV =0), and if all the previous blockshave been correctly received, the BSS sends a Packet Uplink Ack/Nack with

Final_Ack_Indicator set to 0, with the SSN incremented like for an active TBF(SSN = last received BSN +1). All RLC numbering variables are kept as TBF wasstill active. The uplink TBF is now extended and will not be released by the mobile.The BSS starts the timer T_max_extended_UL to monitor the maximum durationof the extended phase.

EXTENDED UPLINK TBF MODEMS capability is know (1/4)

RLCblock,BSN=n,CV=0

MS BSS

PUAN,SSN=n+1,FA

I=0 Enter TBF extended phase.Start T_max_extended_UL


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BSS behavior during the Extended uplink phase

The BSS continues to schedule USF, so that the MS is able to resume an uplinktransfer when required. While the UL TBF is in extended phase, the reception ofan uplink dummy block from the MS, shall not cause the N3101 counter to beincremented in the BSS. Onlyinvalidblock reception increments N3101. While theUL TBF is in extended phase, the reception of an uplink dummy block from the MS

shall not cause the N_UL_dummy counter to be incremented.


RLCblock,BSN=n,CV=0

MS BSS

PUAN,SSN=n+1,FA

I=0 Start T_max_extended_UL

USF

USF

Dummyblock

USF

Dummyblock


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Transfer resumption while UL TBF is in extended phaseIf the RLC layer in the MS receives new LLC data from the upper layer, it begins totransmit RLC data blocks and the TBF is active again. The BSS considers that thetransfer has resumed upon following events:

When receiving a valid RLC data block with a BSN, which is greater than the lastBSN received before switching to the extended phase.

When receiving a radio block, with a correctly decoded header but an invalid data

field. In this case the block is not correctly decoded, N3101 shall be incremented.When the transfer resumes, the BSS stops the timer T_max_extended_UL, theTBF is now in transfer phase.

Depending on the CS_MAX_IDLE_PERIOD expiry, the same coding scheme canbe reused or not (same principle as for DL).

Reception of Packet Resource Request in extended phase

The MS may transmit a Packet Resource Request (in order to request another

RLC mode, ACK/NACK) or another RLC/MAC control message (e.g. PacketMeasurement Report for NC2).

If the MS requests a change of RLC mode when the UL TBF is in extended phase,then the UL TBF shall be released and the TBF will be reestablished by the MS asspecified by 3GPP 44.060. For other RLC/MAC control messages, the normalbehavior applies.



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T_max_extended_UL expiry

The network ends the TBF permanently bysending a Packet Uplink Ack/Nack with FAI= 1 and polling. When receiving PUAN withFAI=1 and polling, the MS sends the PacketControl Ack in response to polling, and thenaborts the uplink TBF.

When the timer T_max_extended_ULexpires, the BSS shall wait for all the radioblocks corresponding to already transmittedUSF, before transmitting FAI =1.

If the radio blocks corresponding to the lastscheduled USF carry RLC data block, thenthe BSS shall restart the uplink TBF.

MS BSS

T_max_extended

_UL expiry

USF

Radioblock,BSN=n+1

USF

Radioblock,BSN=n+2,etc

TBF is active again

Transfer resumption after timer expiry

MS BSS

T_max_extended

_UL expiry

USF

Dummyblock

PUAN,FAI=1,S/P=1

PCA

TBF is release

Nominal case


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Principle to design USF scheduling

USF for extended mode are scheduled only on the PDCH, which carries PACCH.

IF the PDCH supports uplink TBF, which all are in extended mode,

Then,

ifflag EN_FAST_USF_UL_EXTENDED = enable

then the throughput in radio blocks is equally shared between MS (round robin of oneRLC block per MS). So USF are scheduled as follows:

One MS in extended mode on PACCH: USF scheduled every 20ms

Two MS in extended mode on PACCH: USF scheduled every 40ms

n MS in extended mode on PACCH: USF scheduled every n x 20m

ELSE (if the flag EN_FAST_USF_UL_EXTENDED is disabled or if the PDCH supportsat least one MS which is in UL transfer)

A polling period T_extended_UL_TBF_POL, is used for all MS in extended phase. A

default value is 200ms.The remaining bandwidth is used for MS in transfer.

RRBP mechanism has priority above USF scheduling. This means the USFscheduling may be shifted if RRBP request from RLC.

EXTENDED UPLINK TBF MODEScheduling USF


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UL transfer stops when DL is still in transfer

If timer T_max_extended_UL expires while the DL TBF is still in transfer, then the ULTBF is released with no impact on the downlink TBF.

If the DL transfer stops while the uplink TBF has switched to extended state, then thetimer T_Network_response time is started to supervise the maximum duration of thedelayed downlink TBF.

EXTENDED UPLINK TBF MODEInteraction with concurrent DL TBF (1/2)

In transfer

Extended mode

DL

UL

T_max_extended_UL T_max_extended_UL

expires, then UL TBF isreleased while DL goes on

(1) Last UL data block: the UL TBF switches to extended

mode. Timer T_max_extended_UL is started

(2) Last DL LLC PDU; DL TBF enters delayed mode. The

timer T_network response time is started. The polling policy

is exactly the same as for a delayed DL TBF with a

concurrent UL in transfer (T_delayed_DL_TBF_poll_UL).

(3) T_network_response time expires, then the release of

the DL TBF is initiated and T3192 is started.

The uplink TBF in extended mode is released wheneither T3192 expires or T_max_extended_UL expires.

In transfer

Extended mode

DL

UL

still runningT_max_extended_UL

T3192 expires

delayed T3192

T_NW_response_time expiresT_NW_response_time

T3192

event (1) (2) (3)


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DL transfer stops when UL still in transfer

(1) If the DL transfer enters delayed mode, while the uplink is still in transfer, notimer is started.

(2) the last UL block is received, while the downlink is in delayed mode. TimerT_network_response time and T_max_extended_UL are started.

(3) T_network_response time expires, then the release of the DL TBF is initiatedand T3192 is started.

(4) The uplink TBF in extended mode is released when either T3192 expires orT_max_extended_UL expires

EXTENDED UPLINK TBF MODEInteraction with concurrent DL TBF (2/2)

In transfer Extended mode

DL

UL

T3192 expires

=> release extended UL

delayed T3192

T_NW_response_time expiresT_NW_response_time

T3192

T_max_extended_UL

event (1) (2) (3)


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EXTENDED UPLINK TBF MODEOMC-R parameters

HMI name Definition Sub-system

Instance

OMC-Raccess

Type Defvalue

Range Unit

EN_EXTENDED_UL_TBF Flag to disable/enable theextended TBF mode feature onthe uplink

MFS cell Changeable Flag 0 [0,1] None

T_MAX_EXTENDED_UL Maximum duration of theextended uplink TBF phase

MFS cell Changeable Timer 2000 [100,4000]

ms

EN_FAST_USF_UL_EXTENDED

Flag to disable/enable thetransmission of USF every20ms in extended mode

MFS BSS Changeable Flag 1 [0,1] None

EN_RA_CAP_UPDATE Flag to enable/disable theRadio Access Capabilityupdate on Gb

MFS BSS Changeable Flag 0 [0,1] None

RA_CAPABILITY_UPDATE_RETRIES

Maximum number of repetitionof Radio Access capability incase of no answer from SGSNat T5 expiry.

MFS MFS None (DLS) Number 3 - None

T_EXTENDED_UL_TBF_POL

To control the USF schedulingon the uplink when a TBF is inextended TBF mode

MFS MFS None (DLS) Timer 200 [120,500]

ms

T5_RA_CAP_UPDATE Timer to supervise thereception of the MSs currentRadio Access capability fromthe SGSN on Gb.

MFS MFS None (DLS) Timer 5 [1,30] sec


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EXTENDED UPLINK TBF MODEMFS counters (1/2)

Counternumber Name DefinitionP129a CUMULATED_ACTIVE_UL_CONNECTED_TIM

E_GPRS_ACKCumulated time duration of all active UL TBFs established in GPRS modeand RLC acknowledged mode.

Note: An active UL TBF connection is an UL TBF not in extended phase.

P129b CUMULATED_ACTIVE_UL_CONNECTED_TIME_GPRS_NACK

Cumulated time duration of all active UL TBFs established in GPRS modeand RLC unacknowledged mode.


P129c CUMULATED_ACTIVE_UL_CONNECTED_TIME_EGPRS_ACK

Cumulated time duration of all active UL TBFs established in EGPRS modeand RLC acknowledged mode.


P129d CUMULATED_ACTIVE_UL_CONNECTED_TIME_EGPRS_NACK

Cumulated time duration of all active UL TBFs established in EGPRS modeand RLC unacknowledged mode.


P461 CUMULATED_ACT_EXT_UL_CONNECTION_TIME

Cumulated overall time of UL TBF connections (in active state or extendedphase).

P462 NB_DUMMY_UL_BLOCKS Number of Packet Uplink Dummy Control blocks received on the radiointerface.

Note: This counter applies to both GPRS and EGPRS TBFs.


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EXTENDED UPLINK TBF MODEMFS counters (2/2)

Counternumber Name DefinitionP29a CUMULATED_OVERALL_UL_CONN

ECTION_TIME_GPRS_ACKCumulated time duration of all UL TBFs established in GPRSmode and RLC acknowledged mode.

P29b CUMULATED_OVERALL_UL_CONNECTION_TIME_GPRS_NACK

Cumulated time duration of all UL TBFs established in GPRSmode and RLC unacknowledged mode.

P29c CUMULATED_OVERALL_UL_CONNECTION_TIME_EGPRS_ACK

Cumulated time duration of all UL TBFs established in EGPRSmode and RLC acknowledged mode.

P29d CUMULATED_OVERALL_UL_CONNECTION_TIME_EGPRS_NACK

Cumulated time duration of all UL TBFs established in EGPRSmode and RLC unacknowledged mode.

Counternumber Name DefinitionP21a, b,c,d,e NB_UL_RLC_BLOCK_PDTCH_R

ETRANS_CSxRetransmission counters should not be incremented by thePacket Uplink Dummy Control Blocks

P73c, P73d NB_UL_RLC_BYTES_PDTCH_LOST_CS (MCS)

Lost RLC data block corresponding to the USFs scheduledduring the extension phase shall NOT increment P73c norP73d.

P57a,b,c,.up to MCS9

NB_USEFUL_UL_RLC_BLOCK_PDTCH_(M)CSx

Useful blocks shall not take into account the Packet UplinkDummy Control Blocks.

P350b NB_UL_RADIO_BLOCK_PDTCH Total number of radio blocks shall not take into account thePacket Uplink Dummy Control Blocks.


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EXTENDED UPLINK TBF MODENPA indicators (1/2)

Ref. name Name Formula Unit TableName

ARUTBACEAT TIME_UL_TBF_ACTIVE_CONNECT_EGPRS_ACK_OCCUPANCY

P129c seconds GPTRLA

ARUTBACENT TIME_UL_TBF_ACTIVE_CONNECT_EGPRS_NACK_OCCUPANCY

P129d seconds GPTRLA

ARUTBACGAT TIME_UL_TBF_ACTIVE_CONNECT_GPRS_ACK_OCCUPANCY

P129a seconds GPTRLA

ARUTBACGNT TIME_UL_TBF_ACTIVE_CONNECT_GPRS_NACK_OCCUPANCY

P129b seconds GPTRLA

QRPDUDUN UL_RLC_BLOCK_PDTCH_DUMMY_NUMBER

P462 number GPQOS1

QRPDUDUR UL_RLC_BLOCKS_PDTCH_DUMMY_RATE

tdiv ( P462, P350b, 0, 1) % -

QRUDTNRT TIME_UL_TBF_OVERALL_CONNECTION_OCCUPANCY

P461 seconds GPTRLA


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Ref. name Name Formula Unit TableName

QRUDTNREAT TIME_UL_TBF_OVERALL_CONNECT_EGPRS_ACK_OCCUPANCY

P29c seconds GPTRLA

QRUDTNRENT TIME_UL_TBF_OVERALL_CONNECT_EGPRS_NACK_OCCUPANCY

P29d seconds GPTRLA

QRUDTNRGAT TIME_UL_TBF_OVERALL_CONNECT_GPRS_ACK_OCCUPANCY

P29a seconds GPTRLA

QRUDTNRGNT TIME_UL_TBF_OVERALL_CONNECT_GPRS_NACK_OCCUPANCY

P29b seconds GPTRLA

TRPDUTBEAA USEFUL_THROUGHPUT_TBF_UL_RADIO_EGPRS_ACK_AVERAGE

B8: tdiv (P44c,P29c*1000, 0, 0)

kb/s -

TRPDUTBENA USEFUL_THROUGHPUT_TBF_UL_RADIO_EGPRS_NACK_AVERAGE

B8: tdiv (P44d,P29d*1000, 0, 0)

kb/s -

TRPDUTBGAA USEFUL_THROUGHPUT_TBF_UL_RADIO_GPRS_ACK_AVERAGE

B8: tdiv (P44a,P29a*1000, 0, 0)

kb/s -

TRPDUTBGNA USEFUL_THROUGHPUT_TBF_UL_RADIO_GPRS_NACK_AVERAGE

B8: tdiv (P44b,P29b*1000, 0, 0)

kb/s -

EXTENDED UPLINK TBF MODENPA indicators (2/2)


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EXTENDED UPLINK TBF MODERNO indicators

Ref. name Name Formula Unit

ARUTBACEAT GPRS_UL_active_connection_EGPRS_ack_time

P129c seconds

ARUTBACENT GPRS_UL_active_connection_EGPRS_nack_time

P129d seconds

ARUTBACGAT GPRS_UL_active_connection_GPRS_ack_time

P129a seconds

ARUTBACGNT GPRS_UL_active_connection_GPRS_nack_time

P129b seconds

ARUTBACT GPRS_UL_active_connection_time P129a + P129b +P129c + P129d

seconds

ARUTBACP GPRS_UL_active_connection_percent (P129a + P129b +P129c + P129d) /

P461

%

QRPDUDUN GPRS_UL_RLC_block_PDTCH_dummy P462 number

QRPDUDUR GPRS_UL_RLC_block_PDTCH_dummy_rate P462 / P350b %

QRUDTNRT GPRS_UL_connection_time P461 seconds


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EXTENDED UPLINK TBF MODERNO indicators (2/2)

Ref. name Name Formula Unit

QRUDTNREAT GPRS_UL_connection_EGPRS_ack_time P29c seconds

QRUDTNRENT GPRS_UL_connection_EGPRS_nack_time P29d seconds

QRUDTNRGAT GPRS_UL_connection_GPRS_ack_time P29a seconds

QRUDTNRGNT GPRS_UL_connection_GPRS_nack_time P29b seconds


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Availability of Mobile and Tools

Extended UL TBF mode requires R4 mobiles.

In Alcatel plateform, Philips MS Wave E is used

Results obtained with this mobile on plateform :

GPRS: < 300ms for ping 0s , 32 Bytes, target was 350ms

EDGE: < 250ms

On the field, Nokia trace mobiles compliant with R4 are :

Nokia 5140

Nokia 6230i

Alcatel DT tool chain (Nitro tool chain from Agilent) is not providedwith Nokia 6230i and it is not compliant with Extended UL TBF mode.

Need of a viable business case to pay the fee and devote the resources toqualify the phone and add new features(quoted from Agilent)


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Extended UL TBF Mode Ed5