Multicast retry in a communication network

A terminal device for communicating information in a communication network system, the terminal device comprising:

• a processor;
• and
• memory operably coupled to the processor, wherein the memory stores operational instructions that causes the processor to:
• enable the terminal device to serve as an originator terminal device for multicast operation;
• transmit multicast protocol data units utilizing a multicast address to a plurality of destination terminal devices;
• receive, in response to the transmitting, an acknowledgment protocol data unit via a responder destination terminal device of the plurality of destination terminal devices;
• determine whether the transmitted multicast protocol data units are successfully received by the plurality of destination terminal devices based on the received acknowledgment protocol data unit;
• retransmit those of the transmitted multicast protocol data units, which based on the determining, unsuccessfully received at the plurality of destination terminal devices, wherein the retransmission by the terminal device is based on information received from the responder destination terminal device;
• and
• receive a supplemental acknowledgment protocol data unit from a destination terminal device of the plurality of destination terminal devices exclusive of the responder destination terminal device, wherein each of the one or more acknowledgement protocol data units and each of the one or more supplemental acknowledgment protocol data units are received utilizing the multicast address.

A method in a terminal device for multicasting information in a communication network, the method comprising:

• transmitting multicast protocol data units utilizing a multicast address to a plurality of destination terminal devices;
• receiving, in response to the transmitting, an acknowledgment protocol data unit via a responder destination terminal device of the plurality of destination terminal devices;
• determining whether the transmitted multicast protocol data units are successfully received by the plurality of destination terminal devices based on the received acknowledgment protocol data unit;
• when the transmitted multicast protocol data units are unsuccessfully received, retransmitting those of the transmitted multicast protocol data units unsuccessfully received, wherein the retransmission by the terminal device is based on information received from the responder destination terminal device;
• and
• receiving a supplemental acknowledgment protocol data unit from a destination terminal device of the plurality of destination terminal devices exclusive of the responder destination terminal device, wherein each of the acknowledgement protocol data unit and each of the one or more supplemental acknowledgment protocol data units are received utilizing the multicast address.