Slot-based model for IEEE 802.15.4 MAC with sleep mechanism

In this letter, we develop an exactly slot-based model for IEEE 802.15.4 protocol with sleep mechanism in real-time applications. By explicitly modeling the sleep mechanisms and CSMA/CA mechanism with a precision of slot, we accurately evaluate the performance of the protocol, including energy consumption and throughput. We take into consideration the impacts of several factors, including duty cycle, network traffic and initial backoff exponent. NS-2 simulations show the accuracy of the proposed model.