RADIO RESOURCE-ALLOCATION IN FIXED BROAD-BAND WIRELESS NETWORKS

We consider use of fixed broadband wireless networks to provide packet services for telecommuting and Internet access. Each cell in such net works is divided into multiple sectors, each of them served by a secto r antenna colocated with the base station (BS), and user terminals als o use directional antennas mounted on the rooftops of homes or small o ffices and pointed to their respective BS antennas. To support a targe t data rate of 10 Mb/s, a bandwidth of several MHz is required. Since radio spectrum is expensive, the bandwidth needs to be reused very agg ressively. Thus, efficient strategies for frequency reuse and managing cochannel interference are critically important, We propose here seve ral algorithms for dynamic radio-resource allocation in the fixed wire less networks, In particular, a method to be referred to as the stagge red resource allocation (SRA) method uses a distributed scheduling alg orithm to avoid major sources of interference while allowing concurren t packet transmission and meeting signal-to-interference objective. Th e performance of the method is studied by analytic approximation and d etailed simulation, Our results show that the combination of direction al antennas plus the SRA method is highly effective in controlling coc hannel interference, For reasonable system parameters, the SRA method delivers a throughput in excess of 30% per sector while permitting a g iven frequency band to be reused in every sector of every cell. It als o provides satisfactory probability of successful packet transmission. In addition, a simple control mechanism can be applied in the method to improve performance for harsh radio environments.