A novel OFDM-based MAC protocol for wireless LANs

Conventional 802.11 networks perform contention and data transmission serially over the whole channel. This leads to low throughput efficiency. In this paper, we propose a novel CSMA/CQ (carrier sense multiple access/contention queuing) to improve the throughput efficiency. In CSMA/CQ, each node performs contention and data transmission concurrently over two separate subchannels, where a contention queue is introduced to coordinate the concurrency. CSMA/CQ inherits the conventional distributed coordination mechanism on contention, and adopts a centralized control idea on data transmission without requiring strict time synchronization. As a result, CSMA/CQ can achieve far higher throughput than conventional 802.11 networks. Extensive simulations verify that the efficiency of CSMA/CQ.