B.3 Off-network timers
24.3793GPPMission Critical Push To Talk (MCPTT) call controlProtocol specificationRelease 18TS
B.3.1 Timers in off-network group call
B.3.1.1 Basic call control
The table B.3.1.1-1 lists the timers used in basic call control, their start values, their limits, describes the cause of the start, and the action to take on normal stop and on expiry.
Table B.3.1.1-1: Timers in basic call control
|
Timer |
Timer value |
Cause of start |
Normal stop |
On expiry |
|---|---|---|---|---|
|
TFG1 (wait for call announcement) |
Default value: 150 millisecond Configurable. Set to the value of "/<x>/OffNetwork/Timers/TFG1" leaf node present in the UE initial configuration as specified in 3GPP TS 24.483 [45]. |
When the client sends a CALL PROBE message. |
Reception of a CALL ANNOUNCEMENT message. |
Send a CALL ANNOUNCEMENT message. |
|
TFG2 (call announcement) |
Calculated. Refer to section 10.2.2.4.1.1. |
Commencement of group call. |
Termination of group call. When the client Receives a CALL PROBE message or CALL ANNOUNCEMENT message, Re-calculate timer value and restart. |
Send a CALL ANNOUNCEMENT message. Re-calculate timer value and restart. |
|
TFG3 (call probe retransmission) |
Default value: 40 millisecond Depends on the characteristic of the D2D (D2D Sidelink period) Configurable. Set to the value of "/<x>/OffNetwork/Timers/TFG3" leaf node present in the UE initial configuration as specified in 3GPP TS 24.483 [45]. |
When the client sends a CALL PROBE message. |
Reception of a CALL ANNOUNCEMENT message. Or TFG1 Expires. Or User releases the call. |
Send a CALL PROBE message. |
|
TFG4 (waiting for the user) |
Default value: 30 seconds Maximum value: 60 seconds Configurable. Set to the value of "/<x>/OffNetwork/Timers/TFG4" leaf node present in the UE initial configuration as specified in 3GPP TS 24.483 [45]. |
Reception of CALL ANNOUNCEMENT message when not participating in the ongoing call. |
Reception of User action (Accept or Reject). |
Stop incoming call notification. |
|
TFG5 (not present incoming call announcements) |
Default value: 30 seconds Configurable. Set to the value of "/<x>/OffNetwork/Timers/TFG5" leaf node present in the UE initial configuration as specified in 3GPP TS 24.483 [45]. |
Expiration of TFG4 Or User rejects the call. Or User releases the call. |
– |
Reset group call state machine. |
|
TFG6 (Max duration) |
Calculated. Refer to section 10.2.2.4.1.2. |
Commencement of group call |
Termination of group call |
Release the group call |
B.3.1.2 Call type control
The table B.3.1.2-1 lists the timers used in call type control, their star values, describes the cause of start, and the action to take on normal stop and on expiry.
Table B.3.1.2-1: Call type control
|
Timer |
Timer value |
Cause of start |
Normal stop |
On expiry |
|---|---|---|---|---|
|
TFG11 (emergency end retransmission) |
Default value: 1 second Configurable. Set to the value of "/<x>/OffNetwork/Timers/TFG11" leaf node present in the UE initial configuration as specified in 3GPP TS 24.483 [45]. |
When the client sends a GROUP CALL EMERGENCY END message. |
– |
Send a GROUP CALL EMERGENCY END message Increment associated counter by 1. If counter has reached limit, stop the timer. |
|
TFG12 (imminent peril end retransmission) |
Default value: 1 second Configurable. Set to the value of "/<x>/OffNetwork/Timers/TFG12" leaf node present in the UE initial configuration as specified in 3GPP TS 24.483 [45]. |
When the client sends a GROUP CALL IMMINENT PERIL END message. |
– |
Send a GROUP CALL IMMINENT PERIL END message Increment associated counter by 1. If counter has reached limit, stop the timer. |
|
TFG13 (implicit downgrade emergency) |
Calculated. Refer to clause 10.2.3.4.1.1. |
Upgrade of the call to emergency group call. |
Downgrade of the call. |
Downgrade the call. |
|
TFG14 (implicit downgrade imminent peril) |
Calculated. Refer to clause 10.2.3.4.1.2. |
Upgrade of the call to imminent peril call. |
Downgrade of the call. |
Downgrade the call. |
B.3.2 Timers in off-network private call
The table B.3.2-1 lists the timers used in off-network private call, their start values, their limits, describes the cause of start, and the action to take on normal stop and on expiry.
Table B.3.2-1: Timers in off-network private call
|
Timer |
Timer value |
Cause of start |
Normal stop |
On expiry |
|---|---|---|---|---|
|
TFP1 (private call request retransmission) |
Default value: 40 millisecond Depends on the characteristic of the D2D (D2D Sidelink period) Configurable. Set to the value of "/<x>/OffNetwork/Timers/TFP1" leaf node present in the UE initial configuration as specified in 3GPP TS 24.483 [45]. |
When the client sends a PRIVATE CALL SETUP REQUEST message. |
Reception of a PRIVATE CALL ACCEPT or PRIVATE CALL REJECT message. |
Resend PRIVATE CALL SETUP REQUEST message. Increment associated counter by 1. If counter has reached limit, assume the called client is not available. Terminate call setup. |
|
TFP2 (waiting for user to respond ) |
Default value: 30 seconds Maximum value: 60 seconds Configurable. Set to the value of "/<x>/OffNetwork/Timers/TFP2" leaf node present in the UE initial configuration as specified in 3GPP TS 24.483 [45]. |
Reception of a PRIVATE CALL SETUP REQUEST message. |
User responds to the incoming call notification. |
Start TFP7 timer. Send a PRIVATE CALL REJECT message |
|
TFP3 (private call release retransmission) |
Default value: 40 millisecond Depends on the characteristic of the D2D (D2D Sidelink period) Configurable. Set to the value of "/<x>/OffNetwork/Timers/TFP3" leaf node present in the UE initial configuration as specified in 3GPP TS 24.483 [45]. |
When the client sends a PRIVATE CALL RELEASE message. |
Reception of PRIVATE CALL RELEASE ACK message. |
Resend PRIVATE CALL RELEASE message. Increment associated counter by 1. If counter has reached limit, assume the receiving client is not available anymore. Release the call. |
|
TFP4 (private call accept retransmission) |
Default value: 40 millisecond Depends on the characteristic of the D2D (D2D Sidelink period) Configurable. Set to the value of "/<x>/OffNetwork/Timers/TFP4" leaf node present in the UE initial configuration as specified in 3GPP TS 24.483 [45]. |
When the client sends a PRIVATE CALL ACCEPT message. |
Reception of a PRIVATE CALL ACCEPT ACK message or RTP media. |
Resend PRIVATE CALL ACCEPT message. Increment associated counter by 1. If counter has reached limit, assume the receiving client is not available anymore Notify call setup failure. |
|
TFP5 (max duration) |
Configurable. Set to the value of "/<x>/OffNetwork/PrivateCall/MaxDuration" leaf node present in the service configuration as specified in 3GPP TS 24.483 [45]. |
Call establishment. |
Call termination. |
Terminate the call. |
|
TFP6 (private emergency call cancel retransmission) |
Default value: 40 millisecond Depends on the characteristic of the D2D. (D2D Sidelink period) Configurable. Set to the value of "/<x>/OffNetwork/Timers/TFP6" leaf node present in the UE initial configuration as specified in 3GPP TS 24.483 [45]. |
When the client sends a PRIVATE EMERGENCY CALL CANCEL message. |
Reception of a PRIVATE EMERGENCY CALL CANCEL ACK message. |
Resend PRIVATE EMERGENCY CALL CANCEL message. Increment associated counter by 1. If counter has reached limit, assume the receiving client is not available anymore Notify call setup failure. |
|
TFP7 (waiting for any message with same call identifier) |
Default value: 1 second Configurable. Set to the value of "/<x>/OffNetwork/Timers/TFP7" leaf node present in the UE initial configuration as specified in 3GPP TS 24.483 [45]. |
Rejection of a call OR Termination of a call OR Call Failure. |
– |
Reset the call control state machine. |
|
TFP8 (implicit downgrade) |
Configurable. Default value: 180 seconds Set to the value of "/<x>/OffNetwork/PrivateCall/CancelTimeout" leaf node present in the service configuration as specified in 3GPP TS 24.483 [45]. |
|||
|
TFP9 (waiting for call response message) |
Default value: 30 seconds Maximum value: 60 seconds Configurable. Set to the value of "/<x>/OffNetwork/Timers/TFP9" leaf node present in the UE initial configuration as specified in 3GPP TS 24.483 [45]. |
Expiry of timer TFP1 and CFP1 = upper limit and manual commencement mode. |
Reception of PRIVATE CALL ACCEPT or PRIVATE CALL REJECT message. |
Start TFP7 timer. |
B.3.3 Timers in off-network broadcast call
The table B.3.3-1 lists the timers used in off-network broadcast call, their start values, their limits, describes the cause of start, and the action to take on normal stop and on expiry.
Table B.3.3-1: Timers in off-network broadcast call
|
Timer |
Timer value |
Cause of start |
Normal stop |
On expiry |
|---|---|---|---|---|
|
TFB1 (max duration) |
Default value: 300 seconds Maximum value: 600 seconds Configurable. Set to the value of "/<x>/OffNetwork/Timers/TFB1" leaf node present in the UE initial configuration as specified in 3GPP TS 24.483 [45]. |
Start of the broadcast call (terminating UE). |
Receive GROUP CALL BROADCAST END message. |
Terminate participation in the broadcast call. |
|
TFB2 (broadcast retransmission) |
Default value: 3 seconds Maximum value: 10 seconds Configurable. Set to the value of "/<x>/OffNetwork/Timers/TFB2" leaf node present in the UE initial configuration as specified in 3GPP TS 24.483 [45]. |
Start of the broadcast call (originating UE). |
Broadcast call termination. |
Send GROUP CALL BROADCAST message. |
|
TFB3 (waiting for the user) |
Default value: 30 seconds Maximum value: 60 seconds Configurable. Set to the value of "/<x>/OffNetwork/Timers/TFB3" leaf node present in the UE initial configuration as specified in 3GPP TS 24.483 [45]. |
Receipt of GROUP CALL BROADCAST message when user response is required. |
Response from user. |
Terminate incoming call notification. |
B.3.4 Timers in off-network emergency alert
The table B.3.4-1 lists the timers used in off-network emergency alert, their start values, their limits, describes the cause of start, and the action to take on normal stop and on expiry.
Table B.3.4-1: Timers in off-network emergency alert
|
Timer |
Timer value |
Cause of start |
Normal stop |
On expiry |
|---|---|---|---|---|
|
TFE1 (emergency alert) |
Default value: 30 seconds Maximum value: 60 seconds Configurable. Set to the value of "/<x>/OffNetwork/Timers/TFE1" leaf node present in the UE initial configuration as specified in 3GPP TS 24.483 [45]. |
Receipt of GROUP EMERGENCY ALERT. |
Receipt of GROUP EMERGENCY ALERT CANCEL. |
Assume end of emergency state, remove associated user from the list. |
|
TFE2 (emergency alert retransmission) |
Default value: 5 seconds Maximum value: 10 seconds Configurable. Set to the value of "/<x>/OffNetwork/Timers/TFE2" leaf node present in the UE initial configuration as specified in 3GPP TS 24.483 [45]. |
Transmission of GROUP EMERGENCY ALERT. |
Transmission of GROUP EMERGENCY ALERT CANCEL. |
Transmit GROUP EMERGENCY ALERT. |
Annex C (normative):
Counters