The analysis of the optimal contention period for broadband wireless access network

In IEEE 802.16 MAC protocol, the performance of the system is affected by the size of the contention period, since bandwidth request messages are collided during a contention period allocated by a bandwidth allocation MAP message. We stochastically analyze the performance of the system to find the optimal size of the contention period in this paper. To obtain the optimal contention period according to the number of users, we define the cost function using the channel throughput and delay of the system. We also verify the analytic results using OPNET simulator. As the analytic results, it shows that the optimal size of the contention period is about two times of the number of users.