Patent ID: 8351899

Claim:
A method for collecting inter-operator charging information in a group communications system for distributing data or speech packets to mobile stations according to their group memberships, the communications system comprising a first group communications server, a second group communications server and an intermediate charging information collection unit, separate from the first and second group communication servers, provided in an interface between the first and second group communication servers, the group communication servers functioning as push-to-talk over cellular servers, the method comprising: examining, in the charging information collection unit, a group communications message facilitating group communications between group communications participants located in separate networks, transferred over the interface between group communication systems and received from the first group communications server or the second group communications server; generating a charging information unit for inter-operator charging to charge for inter-network resources based on at least a portion of the message; arranging inter-operator charging to charge for inter-network resources using the charging information unit; and transmitting the charging information unit for inter-operator charging to an inter-operator charging system of the first group communications server and the second group communications server.