An adaptive MQAM modulator for fixed wireless ATM networks

摘要

This paper discusses various challenges to realize a fixed wireless ATM network and provides solutions to these challenges. The capacity allocation in wireless ATM, wireless link impact on ATM traffic, and optimum utilisation of the wireless network resources for a LOS wireless ATM link are studied. An adaptive MQAM modulator is introduced to provide an optimum solution to these problems. The modulator level is adjusted using a unique QoS metric in a wireless ATM network. The metric, termed modified effective bandwidth, takes into account the bandwidth demand, QoS requirements, and outage conditions of the wireless ATM link. A performance study using VBR MPEG-1 video traffic in a fixed wireless channel (Ricean channel) demonstrates the advantages of the proposed system.