Modeling and Performance Evaluation of the IEEE 802.15.4K CSMA/CA with Priority Channel Access Mechanism Under Fading Channel

The IEEE 802.15.4 is a well-known standard that is widely utilized for Wireless Sensor Networks due to its low rate and energy efficiency. A novel amendment IEEE 802.15.4k is released for the support of the requirements of critical infrastructure monitoring applications. It is intended to deal with priority packet using the Priority Channel Access (PCA). In this paper, we introduce a new IEEE 802.15.4k protocol through embedding Markov chain models, namely a two dimensional Markov chain model for the IEEE 802.15.4k slotted CSMA/CA with PCA backoff access channel mechanism for priority packet transmission and a three dimensional Markov chain model for the IEEE 802.15.4k CSMA/CA access channel mechanism for non priority packet transmission. Our new model takes into account retry limits, acknowledgment mechanisms, transmission errors and saturated traffic. Furthermore, to test and validate the developed protocol a detailed mathematical expressions of the reliability, power consumption, average delay for successful packet transmission and throughput are given in order to compare the performance of both mechanisms. Moreover parameters that significantly influence on the performance of the network such as network size, Bit Error Rate, packet length and probability that the available packet is priority are analyzed to determine their impact. The obtained numerical results show that a higher reliability, lower throughput, negligible power consumption and lower delay are observed in our new protocol due to the priority channel access instead of the ordinary channel access. Additionally, we conduct a comparative study between our new IEEE 802.15.4k CSMA/CA mechanism and the IEEE 802.15.4 CSMA/CA mechanism. To the best of our knowledge, this is the first work modeling the 802.15.4k mechanisms and evaluating theirs performance under fading channel.