Influence of Backoff Period in Slotted CSMA/CA of IEEE 802.15.4

Low rate wireless applications are under attraction since last decade. For such applications, IEEE designed a standard known as IEEE 802.15.4. The standard operates at 868, 915 and 2400MHz with or without using super frame structure. Most of the low rate Wireless PAN applications follow superframe structure. A superframe structure comprises of contention based and contention free periods by offering slotted CSMA/CA and TDMA like operation respectively. This paper analyzes the performance of slotted CSMA/CA algorithm. CSMA/CA algorithm highly depends upon backoff period that is why its impact is analyzed in this work. The performance analysis is based on probability determined by using discrete markov chain model. The performance analysis comprises of nodes waiting time before transmission, channel busy probability and ultimately throughput and reliability is calculated. Results show that network reliability along with throughput of a wireless network increases gradually with the increase in backoff period at the cost of increase in average wait time of nodes.