Congestion Avoidance Hybrid Wireless Mesh Protocol (CA-HWMP) for IEEE 802.11s

Abstract To support the mobility and low cost deployment, the wireless technology is being used for number of applications. Wireless Mesh Networks (WMN) is one of the evolving technology to provide un-disrupted data connectivity to mobile users. It provides high bandwidth through efficient resource sharing, specially for areas deprived of wired connectivity. These networks also offer self-configuring, self-healing and self organizing capabilities. IEEE 802.11s is a MAC standard being proposed as an enhancement for WMN. This standard includes the use of a mandatory routing protocol at MAC layer, known as Hybrid Wireless Mesh Protocol (HWMP). However, HWMP offers weak response to congestion, especially for interactive applications. IEEE 802.11s has also proposed sharing of Congestion Control Notification Frame(CCNF) on reaching congestion threshold. In this research paper, we have proposed a congestion avoidance technique named Congestion Avoidance Hybrid Wireless Mesh Protocol (CA-HWMP). The proposed technique offers localized re-routing based upon congestion threshold, with minimal overheads. The re-routing decision is taken by the each node using CCNF received from the next hop neighbor. The proposed algorithm do not add any overhead as the CCNF is already the design part of 802.11s. This paper also shows comparison of proposed technique against HWMP under NS3 for the validation of proposed idea. From the comparison we concluded that use of CA-HWMP as replacement of HWMP significantly improves the performance of IEEE 802.11s.