An 802.11-Based MAC Protocol for Reliable Multicast in Multihop Networks

Broadcast/multicast is a service of paramount importance for wireless users, which poses several serious challenges. Many multicast applications, such as multicasting streaming or alarm signalling, require a reliable and efficient medium access control (MAC) layer. However, the current IEEE 802.11 protocol does not offer any MAC layer recovery mechanisms on unsuccessfully delivered broadcast/multicast frames. Consequently, lost frames cannot be detected, hence retransmitted, and this may deteriorate the quality of broadcast/multicast services. To address these issues, we propose a reliable multicast MAC protocol for wireless multihop networks, which aims at providing high packet delivery ratio as well as low control overhead and multicast delivery delay.