Patent ID: 7725101

Claim:
A method in a network unit of a telecommunication system providing network services to one or more user equipments and transmitting data messages of a multimedia broadcast/multicast service (MBMS), said method comprising: receiving MBMS participation requests from the user equipments on a predetermined MBMS-uplink channel; registering the user equipments for an MBMS session based on the received participation requests from said user equipments; receiving on the predetermined MBMS-uplink channel, an acknowledgment message from a user equipment indicating that one or more MBMS-messages has been received; providing charging information in response to receiving the acknowledgment message; transmitting one or more decoding keys to the user equipment for decoding one or more MBMS-messages after having charged the user equipment for previously received MBMS-messages; maintaining a register for storing segment numbers of at least the received acknowledgement messages of each user equipment that participates in an MBMS session; determining from the segment numbers, a missing acknowledgement message; retransmitting the decoding key for decoding the latest transmitted MBMS-message in case of a detected missing acknowledgement message; and omitting the step of providing charging information when receiving from a user equipment, an acknowledgement message comprising an already received sequence number.