A multiple access scheme for wireless access to a broadband ATM LAN based on polling and sectored antennas

An adaptive polling scheme for multiple access in a broadband wireless local area networks (LANs) is proposed. It is designed to accommodate asynchronous transfer mode (ATM) traffic with a large and variable range of bit rates. The radio architecture is microcellular, with switched sectored-beam antennas and a small frequency reuse factor. Features of the multiple access scheme include polling rate depending on a terminal's average bit rate, fixed-length frames divided into segments corresponding to base antenna sectors, and automatic-repeat-request (ARQ) for error control, combined with randomized sector segment ordering. The steady-state performance (cell loss, call blocking and dropping probabilities, waiting time, and buffer occupancy) are evaluated by simulation for an open indoor environment, and for handoff, ARQ, and simple power control enhancements; focusing mainly on the effects of the propagation and interference conditions.