The Optimization of MAC in Hierarchical M2M Networks with Cluster Head

Abstract:

【Abstract】: In hierarchical M2M（Machine-to-Machine）networks with high-density of nodes, the interlayer cluster heads and terminal nodes generally adopt the random mechanism to compete channel, so cluster head or terminal nodes contend for the channel with similar opportunity, especially the cluster head has large amount of data to transmit, which may cause high delay or packet loss. In order to reduce delay and packet loss rate of cluster heads，then presents BT-MAC((Based on Traffic Medium Access Control) algorithm, when terminal nodes and cluster head compete channel, based on the amount of data to be sent algorithm with inverse proportion to set backoff time of the node. So the greater data cluster head transfer, the smaller average backoff time is, equivalent to set cluster head a higher priority, thereby collisions reduce, and the probability of cluster head increase. Simulation results show that BT-MAC algorithm can improve the channel access probability of cluster head thereby to achieve a smaller average delay and can reduce the average energy consumption of nodes, compared to the common DMAC protocol and SMAC protocol.