Performance Analysis of Slotted IEEE 802.15.4 Medium Access Layer

IEEE 802.15.4 is a standard for the medium access control (MAC) and physical layer protocols of wireless networks. This paper provides one of the first analytical evaluations of its MAC protocol for the slotted channel access mechanism in a star topology network. The form of the analysis is similar to that of Bianchi for IEEE 802.11 DCF. The key difference is in the main approximation assumption: Each device’s carrier sensing probability, rather than its packet sending probability, is assumed independent. Also, unlike in 802.11, the slot duration is fixed since the channel is not constantly monitored by the stations. The performance predicted by the analytical model is very close to that obtained by simulation. Research supported by National Semiconductor and ARO-MURI UCSC-W911NF-05-1-0246-VA-09/05 .