Power Fairness in a Scalable Ring-Based Wireless Mesh Network

The wireless mesh network (WMN) is an essential low-power solution to support ubiquitous broadband services. However, mesh networks face the power unfairness and throughput bottleneck issues. Compared to the users far away from the gateway, the users near the gateway need to relay more traffic and consume more power. This paper proposes a scalable ring-based WMN that can ensure power fairness among users by adjusting the ring widths. On top of the ring-based WMN, frequency planning is suggested to overcome the throughput bottleneck issue for the inner-ring users near the gateway, thereby making the system more scalable to accommodate more users and facilitating coverage extension. We also investigate the overall tradeoffs of the ring-based WMN in terms of power fairness, capacity, and coverage. An analytical model is developed to evaluate the throughput and power consumption of the ring- based WMN using carrier sense multiple access (CSMA) MAC protocol in the unsaturated situation. Then, a mixed-integer nonlinear optimization problem aiming to maximize cell capacity and coverage subject to the constraint of power fairness is formulated. Applying this optimization approach, we obtain the optimal number of rings and the associated ring widths of the ring-based WMN.