Channel width adaptation and access in high-density WiFi networks

WiFi will be an important choice to load off the ever increasing data demand of end users in future mobile converged networks, which will inevitably result in high-density WiFi deployments. However, higher density of WiFi networks is not a guarantee to obtain higher throughput, because of the increasing interference among end users and overlapped WiFi networks. As a solution to this problem, this research proposes a flexible framework for fine-grained channel width adaptation and multi-channel access in WiFi networks. The framework adopts DOFDM (Discontinuous Orthogonal Frequency Division Multiplexing) in physical layer, which allocates the frequency resource in the granularity of sub-carrier. And in MAC layer, it uses a frequency-time domain backoff scheme to decrease the access collision, resulting in higher access probability for the contending nodes.