Decoupling Channel Contention and Data Transmission in Dense Wireless Infrastructure Network

In an infrastructure wireless network, with the increase of the number of wireless nodes, the channel collisions become more intense and the network performance declines sharply. In this paper, we propose a novel distributed Media Access Control (MAC) protocol and attempt to decouple the channel contention and data transmission process. Wherein, the channel utilization time is split into channel contention period and data transmission period. During the contention period, the nodes attempt to transmit a short control frame to compete the channel and they will be piped into the potential queue if they succeed. In the following data transmission period, according to the order of the transmission sequence, the node can be scheduled to transmit successively the data packet, and every node will be noticed by the Acknowledgement (ACK) piggybacking. Furthermore, we design an adaptive scheme to adjust the length of the contention period to improve the channel utilization. The simulation results show that our proposed algorithm can improve significantly the performance in terms of system throughput, transmission delay and channel utilization compared to the IO-MAC algorithm and legacy IEEE 802.11 DCF mechanism.