A Novel Approach for Survivability of IEEE 802.11 WLAN Against Access Point Failure

Abstract

In the last decade, wireless networks have become increasingly popular as powerful and cost-effective platforms for mobile communications. Unfortunately, current wireless networks are notoriously prone to a number of problems, such as the loss of link-level connectivity due to user mobility and/or infrastructural failures, which makes it difficult to guarantee their reliability. Today’s users are mostly satisfied with the ability to access wired networks/resources conveniently from mobile stations, even if the access is unreliable. However, as wireless networks become more ubiquitous and start to support more critical applications, users will expect wireless networks to provide the same guarantees of reliability as their wired counterpart are often able to ensure. Research is ongoing to extend the scope of services made available to mobile users to achieve the “anytime, anyplace, any form” communications vision. This vision is to provide voice, data, and multimedia services to users regardless of location, mobility pattern, or type of terminal used for access.

In IEEE 802.11 Wireless LAN, if an access-point fails, then, all the mobile stations connected to a wired network via the access-point may lose connectivity. In this thesis work, the problem of enhancing the survivability of IEEE 802.11 WLAN focusing on tolerating Access Point (AP) failures is addressed. In particular, focus on the problem of overcoming these APs failures working with reconfiguration of the remaining APs by changing parameters like the neighboring AP’s MAC address is done. This approach consists of two main phases: Design and Fault Response. In Design phase, we deal with quantifying, placement and setting up of APs according to both area coverage and performance criteria. In Fault Response phase we consider the reconfiguration of the active APs in order to deal with AP fault in the service area.