A new scheme to improve multi-channel MDA performance in wireless mesh LAN

IEEE802.11s draft proposes a new medium access control function-mesh deterministic access (MDA), which is mainly used for single-channel wireless mesh local area network (LAN). In single-channel environment, collisions between control packets and data packets may occur very often. To reduce the hardware requirements in design, a mesh point only equips single transceiver to support multi-channel environment. To completely avoid the collision between control packets and data packets, the interval of the meshed delivery traffic indication message is first divided into contention period and data transmission period. To provide high performance and network capacity for wireless mesh LAN, this paper proposes a dynamic adjustable contention period (DACP) mechanism and adaptive backoff process (ABP) to improve the performance of the multi-channel MDA (MMDA). The theoretical analysis gives the upper limit of the throughput for DACP. The simulation experiments clearly show the results in multi-channel wireless mesh LAN environment that the proposed scheme performs better than MMDA and the original enhanced distributed channel access (EDCA) in throughput, average waiting time, and packet drop ratio.