MAC Layer Wireless Multicast: Theory and Approaches

Introduction We develop the theory behind wireless MAC layer multicast and obtain throughput optimal transmission policies that provide desired loss and power characteristics. Key idea is to exploit the broadcast nature of wireless channel, i.e, a sender can reach all the receivers in a MAC layer multicast group with a single transmission. Though the broadcast nature of wireless transmissions provides a possible approach to improve the e- ciency of the multicast communication, it also imposes critical challenges. A multicast speci c challenge is that some but not all the receivers may be ready to receive on account of the interference caused by the transmissions in their neighborhood. The readiness state of a receiver depends on the network load. A transmission policy, which does not transmit until all the receivers are ready may have to wait long and hence it may provide low system throughput. On the other hand, if the sender transmits when only a few receivers are ready, then the