Systems and methods for supporting ad hoc group call for MCX services

1. A method for providing ad hoc group calls by a mission critical push to talk (MCPTT) client in mission critical services (MCX), the method comprising:

initiating an ad hoc group call by sending a group call request including a list of participants for the ad hoc group call to an MCPTT server;

receiving a group call response based on successful call establishment of the ad hoc group call from the MCPTT server; and

establishing a media plane and at least one floor control resource for the ad hoc group call.

2. The method as claimed in claim 1 , wherein the group call request further includes at least one mandatory MCPTT participant for the ad hoc group call.

3. The method as claimed in claim 1 , further comprising initiating the ad hoc group call with the participants for an off-network.

4. The method as claimed in claim 1 , further comprising:

selecting a ProSe layer-2 group ID from a pool of configured ProSe layer-2 group IDs;

announcing ad hoc group information comprising the ProSe layer-2 group ID to the participants or a functional alias within a PC5 communication of a PC5 channel dedicated for announcing an ad hoc group communication;

receiving a PC5 communication parameters corresponding to an ad hoc group; and

invoking ad hoc group call set up procedures in an off-network mode.

5. The method as claimed in claim 1 , wherein the MCPTT client, the MCPTT server, and the participants are configured with MCPTT configuration parameters required for supporting ad hoc group communication.

6. The method as claimed in claim 1 , wherein the group call request further comprises at least one of:

a MCPTT ID of the MCPTT client;

a functional alias of the MCPTT client;

a session description protocol (SDP) offer related to offered media parameters;

an implicit floor request indicating that the MCPTT client requests a floor;

a broadcast indicator indicating that the group call request is for a broadcast ad hoc group call;

location information about the MCPTT client; or

information indicating an application priority level requested for the ad hoc group call.

7. A mission critical push to talk (MCPTT) client for providing ad hoc group calls in mission critical services (MCX), the MCPTT client comprising:

memory;

at least one processor; and

a controller operably coupled with the memory and the at least one processor, the controller configured to:

initiate an ad hoc group call by sending a group call request including a list of participants for the ad hoc group call to an MCPTT server,

receive a group call response based on successful call establishment of the ad hoc group call from the MCPTT server, and

establish a media plane and at least one floor control resource for the ad hoc group call.

8. The MCPTT client as claimed in claim 7 , wherein the group call request further includes at least one mandatory MCPTT participant into an ad hoc group call request.

9. The MCPTT client as claimed in claim 7 , wherein the controller is further configured to initiate the ad hoc group call with the participants for an off-network.

10. The MCPTT client as claimed in claim 7 , wherein the controller is further configured to:

select a ProSe layer-2 group ID from a pool of configured ProSe layer-2 group IDs;

announce ad hoc group information comprising the ProSe layer-2 group ID to the participants or a functional alias within a PC5 communication of a PC5 channel dedicated for announcing an ad hoc group communication;

receive a PC5 communication parameters corresponding to an ad hoc group; and

invoke ad hoc group call set up procedures in an off-network mode.

11. The MCPTT client as claimed in claim 7 , wherein the MCPTT client, the MCPTT server, and the participants are configured with MCPTT configuration parameters required for supporting ad hoc group communication.

12. A method for providing ad hoc group calls by a mission critical push to talk (MCPTT) server in mission critical services (MCX), the method comprising:

receiving a first group call request for an ad hoc group call from an MCPTT client, wherein a group call request includes a list of participants for the ad hoc group call;

transmitting a second group call request for the ad hoc group call to each of the participants for the ad hoc group call, wherein the second group call request includes an ad hoc group ID for the ad hoc group call; and

receiving a group call response from each of the participants in response to the second group call request.

13. The method as claimed in claim 12 , further comprising:

determining whether the MCPTT client initiates the ad hoc group call before sending the group call request to the participants based on preset configuration parameters.

14. The method as claimed in claim 12 , further comprising:

adding at least one mandatory MCPTT participant into the first group call request based on preset configuration parameters when the mandatory MCPTT participant is not added by the MCPTT client.

15. The method as claimed in claim 12 , further comprising:

resolving a functional alias into the list of the participants when receiving the first group call with the functional alias as a target and send the ad hoc group call request to the participants.

16. A mission critical push to talk (MCPTT) server for providing ad hoc group calls in mission critical services (MCX), the MCPTT server comprising:

memory;

at least one processor; and

a controller operably coupled with the memory and the at least one processor, the controller configured to:

receive a first group call request for an ad hoc group call from an MCPTT client, wherein a group call request includes a list of participants for the ad hoc group call,

transmitting a second group call request for the ad hoc group call to each of the participants for the ad hoc group call, wherein the second group call request includes an ad hoc group ID for the ad hoc group call, and

receive a group call response from each of the participants in response to the second group call request.

17. The MCPTT server as claimed in claim 16 , wherein the controller is further configured to determine whether the MCPTT client initiates the ad hoc group call before sending the group call request to the participants based on preset configuration parameters.

18. The MCPTT server as claimed in claim 16 , wherein the controller is further configured to add at least one mandatory MCPTT participant into the first group call request based on preset configuration parameters when the mandatory MCPTT participant is not added by the MCPTT client.

19. The MCPTT server as claimed in claim 16 , wherein the controller is further configured to resolve a functional alias into the list of the participants when receiving the ad hoc group call with the functional alias as a target and send the ad hoc group call request to the participants.