An Improvement Algorithm of Slotted CSMA/CA with Service Differentiation and Priority Mechanism

There are two shortages exiting in CSMA/CA: the backoff exponent(BE) increases linearly and it perform not well in the case of CAA2 detected being busy.In this paper, a kind of CSMA/CA algorithm with multi-level priority strategy and service differentiation mechanisms is proposed. Two problems are overcome with different BE based on priority strategy and performing the CAA again after the CCA2 failed slot. Results of experiment on OPNET platform show that the proposed algorithm performs better than the original one in aspects of the throughput, network delay and the probability of successfully access to channel.