Performance Analysis of Wireless LANs with a Backoff Freezing Mechanism

In this paper, we propose an accurate analytical model of IEEE 802.11 DCF WLANs with a backoff freezing mechanism. In order to analyze the DCF with the backoff freezing mechanism, we model the backoff process of a station with a Markov chain. The proposed Markov chain models three different types of the backoff operations: choosing a new backoff counter, freezing the backoff counter, and decrementing the backoff counter. The proposed analytical model also considers the three different types of the previous channel status: idle, busy due to a collision, and busy due to a successful transmission. Considering the backoff freezing mechanism in the proposed model affects the performance measures such as throughput. The analytical and simulation results show that the proposed analytical model is very accurate with the backoff freezing mechanism.