THE GEOMETRIC DYNAMIC CHANNEL ALLOCATION AS A PRACTICAL STRATEGY IN MOBILE NETWORKS WITH BURSTY USER MOBILITY

In this paper we refer to a specific class of Dynamic Channel Allocation (DCA) strategies, namely the interference-free, timid, not-conditioned class, The main concern of this work is to verify if and to what extent strategies belonging to this class can offer better performance than Fixed Channel Allocation (FCA), The interest in this kind of strategies is motivated by their feasibility with current TDM technologies, the limited amount of information required to carry out channel assignments and their intrinsic stability, In this framework we present a simple, but very attractive DCA strategy, the so-called Geometric DCA (GDCA). A performance evaluation is carried out to compare some representative DCA strategies of the considered class, by using a user mobility model that accounts for the large fluctuations of the number of users in a cell coverage area expected in a microcellular environment, The effect of the non-null propagation time required by the information exchange in the DCA strategies is also taken into account. It emerges that the proposed GDCA allows better performance than more sophisticated strategies already proposed, at the expense of a frequency planning carried out only at network configuration, This is due to the ability of GDCA to exploit the a priori information to maintain a tight geometric packing of used carriers. The reported results also show that DCA strategies in the considered class cope with large and sudden traffic fluctuations remarkably better than the FCA scheme does and that the advantage becomes more evident as the burstiness of the user mobility process (hence of the offered traffic) increases.