Protocol issues for the introduction of adaptive antennas into existing second generation systems: GSM and DECT

Mobile communications has become extremely popular and the demand for higher cellular capacities has increased network congestion. Consequently many service providers are looking to improve efficiency within the cellular infrastructure. Adaptive antenna technology offers the possibility of increasing capacity by interference suppression. Implementation of adaptive antennas into current infrastructure cannot take place directly as the current channel allocation algorithms were not designed to consider the spatial properties of these antennas. The paper discusses how the protocol is dependent on two main criteria: are the arrays switched beam or adaptive antennas? Will the network use reduced reuse or channel multiplexing to capitalise on the interference suppression? It examines the protocol issues for Global System for Mobile (GSM) and Digital Enhanced Cordless Telecommunications (DECT), and provides simple channel allocation modifications to enable the use of adaptive arrays within mobile communication systems.