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 (LAN's) 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

Scheduling in a Multi-Sector Wireless Cell

In this thesis, we propose a scheduling problem for the downlink of a single cell system with multiple sectors. We formulate an optimization problem based on a generalized round robin scheme that aims at minimizing the cycle length necessary to provide one timeslot to each user, while avoiding harmful interference. Since this problem is under-constrained and might have multiple solutions, we propose a second optimization problem for which we try to find a scheduling that minimizes the cycle length while being as efficient as possible in resource utilization. Both of these problems are large integer programming problems that can be solved numerically using a commercial solver, but for real time use, efficient heuristics need to be developed. We design heuristics for these two problems and validate them by comparing their performances to the optimal solutions