Communicating the number of participants in a push-to-talk over cellular communication sessions

A communication system for operating a push-to-talk over cellular (PoC) communication session, the system comprising:

• a group of telecommunication devices participating in the PoC communication session, the group of telecommunication devices comprising:
• a first telecommunication device;
• and
• a second telecommunication device;
• a participating function associated with the first telecommunication device;
• and
• a controlling function associated with the second telecommunication device and which controls the joining and leaving of telecommunication devices to and from the PoC communication session;
• wherein the second telecommunication device communicates with the first telecommunication device via the participating and controlling functions respectively associated with the first and second telecommunication devices,
• wherein the first and second telecommunication devices are configured such that when the first telecommunication device desires to send a talk burst to the other telecommunication devices in the group during the PoC communication session:
• the first telecommunication device sends a request to the controlling function via the participating function to send a talk-burst, and
• in response to the request to send the talk-burst, the controlling function generates permission for the first telecommunication device to send the talk burst, and then sends to the first telecommunication device via the participating function a response message indicating that permission is granted to send the talk burst, wherein the response message includes an indication of the number of telecommunication devices currently participating in the PoC communication session and that will receive the talk burst such that without a separate update message being transmitted to the participating function, the participating function can determine the number of telecommunication devices to which the talk burst will be sent.

In a push-to-talk over cellular (PoC) server, a method for controlling the transmission of speech data, the method comprising:

• establishing a PoC communication session between a group of devices registered with a cellular telecommunications network;
• maintaining a record of the devices participating in the PoC communication session;
• controlling the transmission of speech data from a first one of the devices participating in the PoC communication session to one or more of the other devices participating in the PoC communication session by:
• receiving a request from the first device to send speech data to the one or more other devices;
• and
• selectively generating a message which grants the first device permission to send speech data to the one or more other devices, the message including an indication of the number of devices participating in the PoC communication session and that will receive the speech data;
• and
• sending the generated message to the first device, such that without the PoC server transmitting a separate update message, a user of the first device can be charged according to the number of devices that will receive the speech data.