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Timer Name Description

T100 RADIO-LINK-TIMEOUTDetects the presence of the radio link by detecting SACCH

frames every 480 ms.

T200 Data link timerUsed for re-transmission on the data link. The value varies

depending on the message type.

T301 Alerting (ringing) timerTimer used to limit the amount of time a user has to answer a

call.

T303 Mobility Management connectiontimer

Time the network waits after sending a CM SERVICE

REQUEST until receiving a response. This occurs before

initiating call clearing procedures towards the MS.

T305 Release timerTime the network waits after transmitting a DISCONNECT

message until receiving a RELEASE message.

T306 In-band tones release timer

Time the network waits after transmitting a DISCONNECT

message while in-band tones/announcements are provided, until

receiving a RELEASE message.

T308 Release timer

Time the network waits after sending a RELEASE message until

receiving a RELEASE COMPLETE message. This occurs

before re-transmitting the RELEASE or releasing the Mobility

Management connection.

T310 Call proceeding timer

Time the network waits after receiving a CALL CONFIRMED

message until receiving a ALERTING, CONNECT, or

DISCONNECT message before initiating clearing procedures

towards the MS.

T313 Connect acknowledge timer

Time the network waits after transmitting a CONNECT message

until receiving the CONNECT ACKNOWLEDGE message before

performing clearing procedures with the MS.

T323 Modify complete timer

Time the network waits after sending a MODIFY message during

call mode changes, until receiving a MODIFY COMPLETE or

MODIFY REJECT message before initiating call clearing

procedures.

T3101 Immediate assignment timer

Time the network waits after sending the IMMEDIATE

ASSIGNMENT or IMMEDIATE ASSIGNMENT EXTENDED

message until the main signalling link is established before

releasing the newly allocated channels.

T3103 Handover timer

Time the network waits after transmitting a HANDOVER

COMMAND message until receiving HANDOVER COMPLETE

or HANDOVER FAILURE or the MS re-establishes the callbefore the old channels are released. If the timer expires and the

network has not received a correctly decoded L2 (format A or B)

or TCH frame, then the newly allocated channels are released.

T3105 Physical information repetition

timer

Time the network waits after sending the PHYSICAL

INFORMATION message until receiving a correctly decoded L2

(format A or B) or TCH frame. This occur before re-transmitting

the PHYSICAL INFORMATION message or releasing the newly

allocated channels.

T3107 Channel assignment timer

Time the network waits after transmitting an ASSIGNMENT

COMMAND message until receiving the ASSESSMENT

FAILURE message or the MS re-establishes the call before

releasing the old and the new channels.

T3109 Signalling disconnection timerTime the network waits after sending the CHANNEL RELEASE

message before disconnecting the signalling link.

T3111 Channel deactivation afterdisconnection timer

Time the network waits after disconnecting the signalling linkbefore deactivating the channel.

T3113 Paging timer

Time the network waits after transmitting the PAGING

REQUEST message until receiving the PAGING RESPONSE

message. This occurs before re-transmitting the PAGING

REQUEST (if the maximum number of re-transmissions have

not been exceeded).

T3212 Location update timer

The location update timer is set to zero, periodic location update

by the MS are disabled. If the MS camps to the BCH and

decodes a new MCC or MNC from the one it last camped on, it

should perform a location update.

T3250 TMSI reallocation timer

Time the network waits after sending the TMSI

REALLOCATION COMMAND until receiving TMSI

REALLOCATION COMPLETE. This occurs before aborting the

procedure and releasing the Radio Resource connection.

T3260 Authentication response timer

Time the network waits after an AUTHENTICATION REQUESTuntil receiving AUTHENTICATION RESPONSE. This occurs

before aborting the procedure and releasing the Radio Resource

connection.

This is the list of fixed timers with a brief explanation and their values. A timer expiry message app

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Value

4 SACCH multiframes. That is 1.92 seconds if the SACCH is completely absent.

155 ms for FACCH

20 seconds

10 seconds

10 seconds

10 seconds

10 seconds

10 seconds

10 seconds

10 seconds

1 second

2 seconds

50 ms

3 seconds

5 seconds

500 ms

5 seconds

zero = infinite time

5 seconds

5 seconds

ars in its own window, on the test set display. The user has no access to these values and can not change them. None of the fixed timers are active when operating