Analysis of a new fixed channel allocation scheme for a sectorized GSM cellular network

A GSM cellular network contains many cells which are connected to a main control unit called main switching centre (MSC). Each cell is responsible to provide a wireless duplex channel to mobile users of its area. The circuitry used at cells for the above purpose is called base transreceiver station (BTS). The channels in wireless networks are a scare resource thus the allotment of channels to the cells has a greater impact on the traffic performance of the network. It is shown that in terms of traffic capacity the dynamic channel allocation (DCA) algorithms outperform other algorithms (A. Boukerche et al., 2004). But they require heavy signaling and increases delay in channel allocation to the users. On the other hand fixed channel allocation (FCA) is simplest and fastest but have poor traffic capacity due to non uniform nature of the traffic in cellular networks. In some practical scenario neither of these techniques works satisfactory e.g. if one or more low traffic cells are located with heavy traffic surrounding cells; the reasons may be geographical (e.g. a lake exists in centre of city), social (e.g. a low profile area) or any other. In this work we have proposed a new FCA scheme for channel allocation in such scenario. The analysis is done for a sectorized GSM network. We are not addressing the problem of temporary hot spots but we are analyzing the long term traffic imbalance. It is observed that there exits a tradeoff between enhancement in grade of service (GOS) so achieved and the degradation in the voice quality received by cochannel users. This tradeoff is addressed in this work