Performance analysis of service differentiation for IEEE 802.15.4 slotted CSMA/CA

In this paper, we propose two mechanisms, differentiation by backoff exponent and differentiation by the size of contention window, for IEEE 802.15.4 sensor networks to provide multi-level differentiated services in beacon-enabled mode with slotted CSMA/CA algorithm under non-saturation condition. Mathematical model based on discrete-time Markov chain is presented and analyzed to measure the performance of the proposed mechanisms. Numerical results show that the delicate, tuning of throughput could be performed by differentiation by backoff exponent while differentiation by the size of contention window gives more effect for differentiation of throughput.