Handoff management for smart access points in IEEE 802.11 networks

The adoption of IEEE 802.11 wireless networks has grown importantly in previous years. Recently, some vendors are developing smart access points for these networks, which are able to change their operation channel taking interference into consideration. Handoff management in wireless networks, i.e., transferring an active data session from one cell defined by an access point to another, is a critical function. In IEEE 802.11 networks, this function is performed in three phases: discovery, (re)-authentication and (re)-association. Each phase takes an execution time (delay) which interrupts mobile users' connection to the network, ultimately translating in service disruption. In this paper, we propose a probabilistic method to govern the handoff process that does not require modification of the traditional IEEE 802.11 standard and compare it with some traditional methods considering smarts access points. We show that it is possible to reduce the discovery delay by a maximum of 71% compared with standard handoff by reducing the set of channels to probe based on the usage probability of each particular channel.