A CSMA Mechanism with Variable Collision Control and Priority Provision in Multichannel Mobile Ad Hoc Networks

Abstract

Toward making the conventional carrier sense multiple access (CSMA) protocol transmit and control mobile ad hoc network systems, as well as reducing energy consumption, an adaptive multichannel multipriority two-dimensional probability detection and 1-stick joint control strategy carrier sense multiple access with variable collision duration and three-way handshake mechanisms (iCSMA for short) is proposed. Based on the conventional two-slot model of the CSMA protocol, iCSMA introduces a concept of collision duration (b), which divides the system’s timeslot into the duration of successful packet transmission (1 + a), the duration of collision (b + a), and the duration of the idle state (a) of the system. By employing iCSMA, the loss of the system could be reduced with a fine-tuned collision duration (b), which leads to improved performance compared to the conventional 1P-persistent CSMA protocol. Furthermore, a three-way handshake mechanism is introduced for monitoring the entire network system at a minimal cost of throughput. Toward a higher channel utilization rate, a multichannel and multipriority function is employed in the implementation of multiservice communication for the system. Besides, with an adaptive mechanism, the transmission probabilities $p_1$ and $p_2$ are reasonably set so that the system will not produce a complete collision under the condition of high load, and the throughput can also be stabilized. Based on the battery model, the lifetime of the system nodes (T) is extended. Both theoretical analysis and experimental results confirm the accuracy of the theoretical derivation.