Persist: Mitigating route breakages in wireless mesh networks

Although static mesh networks lack mobility, yet research shows that route breakages are quite frequent for reactive protocols in 802.11-based static mesh networks. In 802.11, a link is considered broken if a fixed number of consecutive transmission attempts fail at link-layer. However, transmissions failures can be temporary and may occur due a number of reasons including collisions on the channel or a burst of channel errors, leading to false link (and hence route) breakages which degrade performance. Our proposed scheme “Persist” reduces route breakages in reactive routing protocols in 802.11 based wireless mesh networks by considering the long-term loss-ratio of the links and taking a coherent decision on link breakage by dynamically adjusting the MAC retry limit. A strength of the Persist mechanism is that is extremely simple to implement and can be integrated in existing on-demand routing protocols and provides significant improvements in routing stability and throughput.