Mobility-management and media-access issues in the BAHAMA wireless ATM LAN

We previously proposed an ad-hoc wireless ATM LAN/PBX, in which portable base stations (PBSs) can be deployed in an arbitrary topology to support mobile users with multimedia laptop computers. In this network, which we call BAHAMA, mobile users can communicate with one another directly as peer-to-peer if they are close by, or using the PBS backbone LAN. The user wireless links are assumed to be in the 2- to 20-Mb/s range, adequate for most video, data, voice and multimedia applications, The PBS-to-PBS links can either be wired or wireless and are assumed to be high speed (Gb/s). The PBSs are simple, compact and low-cost switching nodes performing cell routing. They can be relocated since the network design allows for ad-hoc configurations, i.e., self-configuring and self-organizing capabilities. There are many challenges to be addressed in such a wireless ATM LAN. In this paper, after presenting some background material on the BAHAMA project, we discuss several important issues in two key areas: mobility management and media access. Mobility management is needed because wireless users are free to roam about the network. Media access protocols are the means to allow shared, wireless access by multiple, mobile users.