Capacity analysis of CSMA/CA based wireless networks under coexisting heterogeneous devices

The unlicensed Industry-Science-Medical (ISM) band is getting overly populated by coexisting heterogeneous wireless devices, including wireless personal area network (WPAN) and wireless local area network (WLAN) devices. Due to their heterogeneity and incompatibility, the coexistence between these devices has been a challenging problem. In this paper, an analytical model in which a simple closed-form expression for the capacity of wireless networks adopting carrier sense multiple access with collision avoidance (CSMA/CA) is provided, considering heterogeneous system parameters and multi-channel operations. In addition, using the proposed model, the log-convexity of capacity region of such networks is established. Results demonstrate the accuracy of the proposed model, and hence, can provide a fundamental theoretical background when designing or deploying such heterogeneous networks and devices.