B.2 On-network timers
24.2813GPPMission Critical Video (MCVideo) signalling controlProtocol specificationRelease 18TS
B.2.1 Timers in the controlling MCVideo function
The table B.2.1-1 provides a description of the timers used by the controlling MCVideo function, specifies the timer values, describes the reason for starting of the timer, normal stop and the action on expiry.
Table B.2.1-1: controlling MCVideo function timers
|
Timer |
Timer value |
Cause of start |
Normal stop |
On expiry |
|---|---|---|---|---|
|
TNG1 (acknowledged call setup timer) (NOTE 1) |
Obtained from the group document in the <on-network-timeout-for-acknowledgement-of-required-members> element as specified in 3GPP TS 24.481 [24]. |
On reception of a SIP INVITE request to start a group session where the group document contains <on-network-required> group members as specified in 3GPP TS 24.481 [24]. |
On receipt of all SIP 200 (OK) responses to all SIP INVITE requests for <on-network-required> group members as specified in 3GPP TS 24.481 [24]. |
Either proceed with the set-up of the call or abandon the call. |
|
TNG2 (in-progress emergency group call timer) (NOTE 2) |
Obtained from the <group-time-limit> element of the <emergency-call> element of the <on-network> element of the service configuration document as specified in 3GPP TS 24.484 [25]. |
On reception of a SIP INVITE request or SIP re-INVITE request that initiates an MCVideo emergency group call. |
On acceptance of a request to cancel the in-progress emergency state of a group. |
Cancels the in-progress emergency state of the group and return the session and/or call to normal priority level. |
|
TNG3 (group call timer). (NOTE 1). |
Set to the value of the <on-network-maximum-duration> element from the group document. |
On reception of a SIP INVITE request to start a group session after retrieval of the group document from the group management server. For a temporary group call, when merging active group calls into a temporary group call. When splitting a temporary group all into independent active calls |
When the last MCVideo client has left the session. When a temporary group call is split into independent active calls. For active group calls, when merging them into a temporary group call. |
Release the group call. |
|
NOTE 1: More than one instance of this timer can be running in the controlling MCVideo function, each instance associated with a specific group call. NOTE 2: More than one instance of this timer can be running in the controlling MCVideo function, each instance associated with a specific in-progress emergency state of a single group |
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