Reliable Multicast MAC Protocol for Spatial Reuse Efficiency Assisted by Multicarrier DS-CDMA in WLAN Systems
The authors propose a reliable multicast MAC protocol based on the multicarrier direct-sequence code-division multiple access (MC DS-CDMA) scheme to enhance spatial reuse efficiency in Wireless Local Area Networks (WLANs). Conventional multicast MAC protocols using RTS-CTS handshake exchange CTS and ACK packets consecutively for reliable transmission. Although this protocol guarantees transmission reliability by avoiding the Hidden Node (HN) problem, multiple CTSs and ACKs degrade network efficiency and cause the well-known Exposed Node (EN) problem, rather than the HN problem. The multicast sender must receive multiple CTSs and ACKs from all multicast receivers in its own multicast group for reliable multicast.