Route Stability in Wireless Mesh Access Networks

Abstract

Wireless mesh access networks (WMANs) have become popular to provide 'last-mile' broadband wireless Internet access to large communities. Wireless mesh access networks comprise of powerful, dedicated routers which act as the backbone access networks for users. Wireless mesh access networks have neither mobility nor energy constraints as the routers act as fixed wireless access points for providing multihop high-speed wireless access to Internet. Conventional mesh and ad hoc routing protocols perform poorly in WMANs despite lack of mobility and energy-constraints. The main problem is instability of routes as frequent route breakages have been observed (K. Ramachandran et al., 2007) in the wireless backbone which is otherwise a stationary network. Existing protocols mistakenly consider momentary transmission failures on a wireless link as link breakage. In reality, transmission problems are often temporary, caused by transient congestion on the wireless links. We propose a new route stability mechanism which provides significant improvements in existing mesh routing protocols by making routes resilient to transient transmission failures which occur due to congestion. Simulations show an improvement of up to 75 percent in throughput and up to 40 percent reduced delays.