CELLULAR SYSTEMS

BSS R&D Activity

Release 4

Release 2 : S/P2/3.7.2.1

Version Date Author Reason for update

2.0.0.0 05/06/92 M.Montague Phase 2 document collating and information from the followingphase 1 documents and phase 2 specnotes :BSG/102 Phase1 document: interface-Abis. TLA/SN/25 LapDimprovement CCITT-Q.921 Digital subscriber signallingSystem No.1,data link layer. Main changes : new management ofFU and TCU restarts, congestion control, flow control for UI-frames, performance counters

2.0.1.0 09/07/92 M.Montague Reissued with modification requests from review. Ref: Minutes ofTLA Review Meeting (TLA/135).

2.0.1.1 15/02/93 P.Vincent Reworked after TLA/RSG meeting (RSG/157). Some paragraphsof the first section (transmission aspects) have been removed. Achapter concerning Abis link failure has been added.

2.0.2.0 19/05/93 P.Vincent TLA approved (refer to minutes RSG/164)

2.0.3.0 11/06/93 P.Vincent New TLA approved version (refer to minutes TLA/153) awaitedRSG approval by mail.

2.1.0.0 09/07/93 P.Vincent RSG approved version after comments received for the OML

Release 3 : 3BK 11202 0037 DSZZA

Version Date Author Reason for update

3.0.0.0 16/03/94 E.I.Hughes Initial version for release 3. Editorial clarifications.

3.1.0.0 2/05/94 E.I.Hughes Level 2 approved version after comments from C.H.Chin. (seeminutes of TLAr3#7,SYS/051)

Release 4 : 3BK 11202 0089 DSZZA

Version Date Author Reason for update

4.0.0.0 27/04/95 B. Gleizes First version for release 4. Impacts of 16 kbit/s RSL on LAPD :window size, UI queue length, higher priority of I frame over UIframe, conditional generation of RR frames. Editorial correction ofchapter 3.4.2.1 "FU restart" in order to align the specification toimplementation (PR 10730). Specification of the maximumsignalling flow on RSL.

4.0.1.0 24/05/95 B. Gleizes Second version for release 4. changes after TLAr4#13 (minutesSYS/182)

4.1.0.0 15/06/95 B. Gleizes Approved version for release 4.

4.2.0.0 11/10/96 JY Amaudrut Updated according to the CRQ 2221, 2232, 2695.

BTS

BSC

PCM link

BSI link

BTS

BTS

BIE BIE

BSC

PCM link

BSI link

BTS

BTS

BTS BIE

BIE

BIE

BIE

BSC

PCM link

BSI link

BIEBTS

BIE

BIE

BIEBTS

BTS

MSC

A-itfAter-itfBS-itf BS-itfAbis-itf

BTS BIE BIE BSC

BTS BSC

TC MSC

TCU 1

BTS BSC

RSL_1

RSL_n

OMLOMU

FU n

FU 1{ TEI, SAPI }

TCU n

. . . . . .

OMUOML

RSL_n

FU 1RSL_1

FU n

TCU n+1

{ TEI, SAPI }

BTS BSC

TCU 1

TCU n

. . . . . .

BSCBTS

TCU 1{ TEI, SAPI }

OMUOML

RSL n-1

RSL n

RSL 0

RSL 1

TCU n/2

FU 1

FU n-1

FU n

FU 0

. . .. . .

BSCBTS 1

TCU 1{ TEI, SAPI }

RSL n-1

RSL n

RSL 0

RSL 1

TCU n/2

FU 1

FU n-1

FU n

FU 0

. . .. . .

TCU 1+n/2{ TEI, SAPI }

OMUOML

RSL m-1

RSL m

RSL 0

RSL 1

TCU m+n/2

FU 1

FU n-1

FU n

FU 0

. . .. . .

BTS 2

% age ofbuffers used

High Threshold shouldbe less than the maxnum of buffersavailable

ThresholdLow

ThresholdHigh

1st DL_congestion msg sent here

DL_congestion_endsent here

every N_WAIT DL_data_reqmsg received from L3between times t=a andt=b will cause a congestionmsg to be sent

time ( t ) t = a t = b

(a)

(b)

(c)

(d)

time (t)

BF_TR_HI

BF_TR_LO

%age of RX buffersin use

LAPDTIMERS

VALUE

BSC BTS(OMU) BTS(FU)

T200 300 ms 300 ms 270 ms

T203 4 secs 10 secs 4 secs

T_delay 10 secs 10 secs not implemented

BCCH_Cut none none 210 secs

LAPD PARAMETERS

Parameter RANGE VALUE

N200_BTS (RSL)

N200_RSL (BSC)

N200_OML (BSC)

N200_OML (OMU)

N201

K_LapD_RSL(BTS-max.number of outstanding

frame)

K_LapD_OML(BTS-max.number of outstanding

frame)

K_VAL_RSL(BSC-max.number of outstanding

frame)

K_VAL_OML(BSC-max.number of outstanding

frame)

I_LAPD_MAX_RX (Max. noI-frames in the RX buffer -

BTS only)

I_LAPD_MAX_TX (Max. noI-frames in the TX buffer -

BTS only)

UI_LAPD_MAX_TX (Max. noUI-frames in the TX buffer -

BTS only)

1-16

1-16

1-16

1-16

5 - 25

5- 150

2 - 20

10

12, Note 1

3

3

260

4 or 7, Note 2

2

4 or 7, Note 2

2

10 (14 for theOMU)

120 (5 for theOMU)10 Note

3

Occupancy level

Threshold Minimum Maximum Default

BF_TR_LO

(in BSC)

1 100 % 70 %

BF_TR_HI

(in BSC)

1 100 % 80 %

THRES-LOW-TX

(BTS)

0 100 % 70 %

THRES-HIGH-TX

(BTS)

0 100 % 80 %

Alarm Threshold Values

Parameters Threshold value Interval timer(1)

CRC Error

Invalid Address

Inactive DLCI(BTS only)

Short frame (BTS only)

Discarded Frame(BTS only)

Aborted Frame(BTS only)

DMA overrun

DMA underrun

N_WAIT - BTS only (Thresholdcounting spacing between

DL_data_congestion_ind - range 1 ..20)

50 (2)

60 (2)

2E+16

2E+16

2E+16

2E+16

2 (2)

2 (2)

5

10 secs

15 sec

none

none

none

none

1 sec

1 sec

SAPI Value Table

SAPI VALUE LapD Entities

0

62

LapD on the RSL

LapD on the OML or TSL

Feature No Feature Description

Release 1 & 2

A 1613

A 1615

B 2105

B 2107

B 2111

B 2115

Release 4

8.1a

GSM Abis interface Layer 2: RSL

GSM Abis interface Layer 2: OML, 1 per OMU

Abis: Radio Signalling link (RSL)

Abis: Operation and Maintenance Link (OML)

Abis: fixed TEI's(no TEI management)

specific TEI for each TRX

Abis signalling links submultiplexing schemes -16 kbit/s static sub-multiplexing