Autonomous reuse partitioning in cellular systems

Abstract

A simple, decentralized procedure for adaptive channel allocation, autonomous reuse partitioning (ARP), is proposed. Radio channels are viewed in the same order at any base station, and the first channel that satisfies a carrier-to-interference ratio (CIR) threshold is allocated. ARP easily achieves reuse partitioning, in which channels higher in the order are reused at shorter distance by mobile stations from which stronger signal levels are received. An efficient frequency reuse pattern helps ARP to improve traffic handling capacity while avoiding interference. Performance was evaluated by means of computer simulation in which a system accommodating portable units with 70 channels is assumed. Compared with random channel allocation, ARP doubles traffic handling capacity and decreases the probability of interference by 1/4. Actual transmitter power control is shown to improve capacity by 9%. ARP improves traffic handling capacity at the cost of CIR margin in each channel. This can create problems for mobile stations, such as car-mounted units, which suffer rapid fluctuation in signal levels.