Cross-layer Design of Optimal Contention Period for IEEE 802.16 BWA Systems

In IEEE 802.16 broadband wireless access (BWA) systems, the uplink performance is affected by the size of the contention period in the subframe since the bandwidth request (BR) messages are sent during the period and the bandwidth for each service can be allocated only when the BR messages are accepted. In this paper, we develop a cross-layer analytical model for designing the optimal size of the contention period in IEEE 802.16 BWA systems with various classes of services. The model is validated by Monte Carlo simulation, and the results show that our cross-layer design provides a good scheme for determining the contention period size when the system performance is optimized.