10.16 Remotely initiated MCPTT call
23.3793GPPFunctional architecture and information flows to support Mission Critical Push To Talk (MCPTT)Release 18Stage 2TS
10.16.1 General
A remotely initiated MCPTT call allows an authorized user to cause a remote MCPTT UE to initiate a call by itself, without its user explicitly initiating the call.
10.16.2 Information flows for remotely initiated MCPTT call
10.16.2.1 Remotely initiated MCPTT call request
Table 10.16.2.1-1 describes the information flow remotely initiated MCPTT call request from the MCPTT client to the MCPTT server and from the MCPTT server to MCPTT client.
Table 10.16.2.1-1: remotely initiated MCPTT call request information elements
|
Information Element |
Status |
Description |
|
MCPTT ID |
M |
The MCPTT ID of the called party (remote) |
|
Notification to remote user of remotely initiated call |
M |
Use to determine whether the called party (remote) receives any indication of the remotely initiated MCPTT call. |
|
MCPTT ID |
O (see NOTE) |
For a remotely initiated MCPTT private call the MCPTT User ID to be called |
|
MCPTT Group ID |
O (see NOTE) |
For a remotely initiated MCPTT group call to use. |
|
Requested commencement mode |
O |
Requested commencement mode for the remotely initiated MCPTT private call. |
|
Requested priority |
O |
Requested priority for the remotely initiated MCPTT private call or MCPTT group call. |
|
NOTE: One and only one of these shall be present. |
||
10.16.2.2 Remotely initiated MCPTT call response
Table 10.16.2.2-1 describes the information flow remotely initiated MCPTT call response from the MCPTT client to the MCPTT server and from the MCPTT server to MCPTT client.
Table 10.16.2.2-1: Remotely initiated MCPTT call response information elements
|
Information Element |
Status |
Description |
|
MCPTT ID |
M |
The MCPTT ID of the calling party |
|
MCPTT ID |
M |
The MCPTT ID of the called party |
|
Result |
M |
Result of the remotely initiated MCPTT call request – success or fail. |
10.16.3 Procedure
10.16.3.1 Remotely initiated MCPTT call request
The remotely initiated MCPTT call request procedure includes the initial remotely initiated MCPTT call request from the MCPTT user to the remote UE and either the MCPTT private call procedures or the MCPTT group call procedures originating at the remote UE.
Procedures in figure 10.16.3.1-1 show the signalling control plane procedures for the MCPTT client initiating a remotely initiated MCPTT call request with the chosen MCPTT user.
Pre-conditions:
1. If the MCPTT user on MCPTT client 1 wants the resulting remotely initiated MCPTT call to be:
a. an MCPTT group call, then MCPTT user 2 on MCPTT client 2 is an affiliated MCPTT group member of the MCPTT group that is the target of the remotely initiated MCPTT call.
b. an MPCTT private call, then the MCPTT user 2 on MCPTT client 2 is permitted to initiate an MCPTT private call to the identified MCPTT user.
Figure 10.16.3.1-1: Remotely initiated MCPTT call request
1. MCPTT user on MCPTT client 1 initiates a remotely initiated MCPTT call request to the MCPTT user of MCPTT client 2.
2. MCPTT client 1 sends a remotely initiated MCPTT call request towards the MCPTT server.
3. MCPTT server checks whether the MCPTT user at MCPTT client 1 is authorized to initiate a remotely initiated MCPTT call request. If the resulting of this request is to initiate a group call, MCPTT client 1 is authorized to remotely initiate the MCPTT call request, and if MCPTT client 2 is a member of the group, the MCPTT server implicitly affiliates the MCPTT user 2 on MCPTT client 2 to the MCPTT group if the MCPTT client 2 is not already affiliated and notifies the MCPTT client 2 of this affiliation change.
4. If authorized, MCPTT server sends the corresponding remotely initiated MCPTT call request towards the MCPTT client 2.
5. Based on the received information the receiving MCPTT client 2 may notify the user of the remotely initiated MCPTT call request.
6. Optionally the receiving MCPTT client 2 sends a remotely initiated MCPTT call response to the MCPTT server.
7. After receiving the remotely initiated MCPTT call response from MCPTT client 2, the MCPTT server informs the MCPTT client 1 about successful remotely initiated MCPTT call request.
NOTE 1: Step 6 and step 7 might not be sent, since it could be determined that the remotely initiated MCPTT call was successful by receiving the MCPTT call initiated by MCPTT client 2.
8. Based on the received information the MCPTT client 2 initiates an MCPTT call (either an MCPTT group call or an MCPTT private call) using the normal MCPTT call establishment procedures (10.6.2.3.1.1.2 or 10.7.2.2) with implicit floor request and other call set up parameters if received in the remotely initiated call request. The MCPTT call request may include the additional information such as indication of whether the call initiation is due to receiving of remotely initiated call request.
NOTE 2: Step 6 and step 7 are received in this order. However, step 6 or step 7 or both might occur before or after step 8.
NOTE 3: The received information can have call setup related information, such as requested application priority level, commencement mode, etc.
9. If the remotely initiated call is a group call, then when the ongoing MCPTT group call is terminated, the MCPTT server de-affiliates the MCPTT user 2 on MCPTT client 2 from the MCPTT group if MCPTT client 2 is implicitly affiliated as defined in the step 3 above (the de-affiliation is not shown in the figure for simplicity).
The result of these procedures is an on-going MCPTT (group or private) call which includes MCPTT client 1.