A novel time-slot allocation scheme for ad hoc networks with single-beam directional antennas

Wireless ad hoc networks with directional antennas will dramatically improve capacity by using TDMA-Based MAC layer protocol. Time-slot allocation is a crucial stage in TDMA, with which we are concerned. To the best of our knowledge, previous allocation strategies fail to achieve a satisfactory trade-off between utilization and fairness, especially with single-beam antennas. This paper proposes a novel allocation scheme to realize a better result under single-beam situation. A node collects traffic information in the neighborhood periodically, so as to coordinate among links and adapt to variable load changes. By solving graph coloring problem through a heuristic way respectively, nodes at both ends of a link jointly determine the maximum number of time slots can be reserved for that link. Preliminary simulation results using OPNET are presented, reflecting that our method successfully eliminates starvation of any link and obtains relatively high channel utilization at the same time.