The Study of MAC Protocol Fairness for WBANs

The IEEE 802.15.4 standard is specifically devised to support low power, low data rate in relation to Wireless Body Area Network (WBAN). It is pointed out that weaknesses of channel allocation unfairness when using DCF access control scheme due to its inherent nature of binary exponentially backoff algorithm. So, this paper proposes an improved back off algorithm in slotted CSMA/CA, to dynamically change the minimum contention window each time CSMA/CA begins, according to the network load conditions. The presented based on Two-dimensional Markov chain model. Theoretical analysis and simulation results show that the proposed algorithm can decrease the collision ratio and the retransmission ratio, resulting significant power saving and throughput improvement when the traffic load is high.