Development and experiments of highly reliable multicast in wireless multihop networks

When multicasting through wireless multihop networks, frame losses at the wireless link cause data losses at the application layer because of no ACK (Acknowledgment) at both data link layer and transport layer. The authors propose a novel multicast scheme to reduce data losses at the application layer and to improve reliability. The scheme incorporates a retransmission mechanism into the data link layer and selects the reliable IP-based unicast paths. The verification of the proposed multicast scheme is performed with wireless LAN interface equipped nodes in an actual office environment, where an NTSC-Quality MPEG4 movie was successfully forwarded to a 5-hop destination node.