19 List of system variables

09.183GPPGeneral Packet Radio Service (GPRS)Gs interface layer 3 specificationServing GPRS Support Node (SGSN) - Visitors Location Register (VLR)TS

19.1 Timers

This subclause lists the management timers specified for the operation of the BSSAP+ protocol. All the implementation shall support the range of values specified below. The specific value of the timers shall be under the control of the operator.

Table 19.1/3GPP TS 09.18: Management Timers

Timer name

Default value

Timer range

Granula-rity

Notes

Relation to other timers

T5

2-20 secs

100 ms

Guards the Paging procedure at the VLR.

Value is correlated to DRX parameter Split PG CYCLE (max possible = 16 sec) Default should be set acc. to max split cycle supported by the SGSN (operator choice)

T6-1

10-90 secs

1 sec

Guards the Location Update procedure.

It should be higher than 2 times the maximum transmission time in the Gs interface, plus the supervision timer of the Update Location procedure [3GPP TS 09.02]

T6-2

40 secs

5-60 secs

1 sec

Guards the TMSI reallocation procedure.

It should be higher than 2 times the maximum transmission time in the Gs interface, plus 4 times T3350 [3GPP TS 04.08]

T7

4 secs

1-30 secs

1 sec

Guards the Non-GPRS alert procedure.

None.

T8

4 secs

1-30 secs

1 sec

Guards the Explicit IMSI detach from GPRS services procedure.

None.

T9

4 secs

1-30 secs

1 sec

Guards the Explicit IMSI detach from non-GPRS services procedure.

None.

T10

4 secs

1-30 secs

1 sec

Guards the Implicit IMSI detach from non-GPRS services procedure.

None.

T11

4 secs

1-120 secs

1 sec

Guards the VLR reset procedure.

None.

T12-1

8 – 60×384+8 secs

1min

Controls the resetting of the ‘SGSN-Reset’ variable.

It should be longer than the longest Periodic RAU timer running on the SGSN, plus the transmission delay on the radio interface.

T12-2

4 secs

1-120 secs

1 sec

Guards the SGSN reset procedure.

None.

T14

4-36 secs

1 sec

Guards the MS Information procedure.

None

NOTE: The Default value is the recommended value.

19.2 Retry counters

This subclause lists the management retry counters specified for the operation of the BSSAP+ protocol. The values indicated are recommended values.

Table 19.2/3GPP TS 09.18: Management Retry counters

Retry mnemonic

Retry value

Notes

N7

2

Recommended value

N8

2

Recommended value

N9

2

Recommended value

N10

2

Recommended value

N11

2

Recommended value

N12

2

Recommended value

Annex A (informative):
Change History

Change history

Date

TSG #

TSG Doc.

CR

Rev

Subject/Comment

Old

New

December 2001

CN#14

Conversion to 3GPP layout and number

GSM 09.18 v6.6.0

3GPP TS 09.18 v6.6.0

12-2001

NP-14

NP-010646

A046

Clarification of the periodic routing area update procedure

6.6.0

6.7.0

12-2001

NP-14

NP-010646

A048

1

Correction of the Reject cause used when T6-1 expires

6.6.0

6.7.0