Cell load based user association for professional mobile radio systems

When the public communication networks can not provide service during disaster and high traffic cases, Professional Mobile Radio systems (PMR) such as trunked Digital Mobile Radio (DMR) systems are needed to improve the service quality and to provide uninterrupted service to the public safety officers. While providing continuous voice and data service, it is very important to select the base station (BS) to be served by efficient cell selection algorithms. The aim of the user association algorithms is to reduce the waiting time while establishing reliable transmission link for PMR systems in emergencies. In this sense, we propose the full set user association algorithm that each user selects the BS according to the calculated utility value determined based on both received signal strength indicator (RSSI) value and cell load information. The performance of the proposed algorithm is evaluated by considering different performance metrics for trunked DMR systems in urban area.