Medium Access Cooperations for Improving VoIP Capacity over Hybrid 802.16/802.11 Cognitive Radio Networks

There are some existing works that study the coexistence of 802.16 and 802.11 networks. However, not many of them consider the resource allocation issues in the case of delivering traffic between mobile stations and Internet users through an access point (AP) and a base station (BS) which operate at the same frequency band. In this paper, we design a cooperation mechanism for 802.16 and 802.11 to share the same medium with adaptable resource allocation. The adaptiveness in resource allocation in our design eliminates the potential inefficiency from the cooperation due to bandwidth bottleneck. Targeting VoIP applications, we propose a simple approach for the adaptation that optimizes the resource allocation not only between the IEEE 802.11 AP and the stations but also between the IEEE 802.16 BS and the IEEE 802.11 AP. Numerical results show significant improvement in voice capacity.