We propose and analyze a resource allocation algorithm, referred to as the enhanced staggered resource allocation (ESRA) method, for fixed broadband wireless networks with directional antennas at base stations and terminals. The new method is based on the staggered resource allocation (SRA) algorithm with consideration of reception quality at terminals. Terminals are categorized into multiple classes, depending on their ability to tolerate concurrent packet transmissions. The purpose of the ESRA method is to maximize concurrent transmissions up to an extent tolerable by the receiving terminals for throughput improvement, while avoiding major cochannel interference in the networks where frequency is reused very aggressively. For practical radio parameters, the ESRA method provides 98.69% coverage and yields a maximum downlink throughput of 36.10% per sector while meeting a 15 dB signal-to-interference ratio (SIR). As for the uplink, using full power control, the throughput reaches 16.7% per sector with a packet loss probability of less than 5/spl times/10/sup -4/. The high ESRA throughput translates into a very large network capacity, and the high quality of service reveals that the new method can support real-time traffic such as voice and video, as expected in future broadband multimedia services in fixed wireless networks.

We have proposed and studied the performance of a measurement based MAC protocol for wireless packet data communications in the presence of co-channel interference. A fuzzy logic based algorithm is used to control the permission probability of each TDMA slot based on the interference and traffic conditions. This algorithm provides an adaptive access mechanism to achieve a balance between traffic throughput and signal quality. We performed computer simulations to study the protocol sensitivity to various system parameters. Performance measures includes average delay, protocol efficiency and channel utilization. Compared with the unmodified PRMA, this protocol can provide significant improvement since it is adaptive to traffic intensity and interference conditions. This method may also be suitable for multimedia wireless access.