Abstract:

The most serious problem of the wireless multicast system is the all users’ QoS (Quality of Service) demands can not be satisfied simultaneously for the variety and unequality of users’ channels. In wireless cellular communication systems, packets should inevitably be transmitted multiple times to achieve reliable multicast，which increases the multicast latency. In this paper, we first analyze the latency of cooperative multicast scheduling (CMS) and derive the minimal latency at the assumption that we know the total channel state information. In addition, an opportunistic cooperative multicast scheduling (OCMS) strategy is proposed to optimize the multicast latency on the condition that only part of the channel state information is achieved by some feedback signals. The simulation results show that the proposed strategy almost reaches the optimal latency of CMS and outperforms other schemes markedly on the performance of transmission latency.

Key words: multicast latency;opportunistic cooperative multicast scheduling;reliable multicast