On optimizing the routing algorithms of a GSM infrastructure network for supporting time critical applications

GSM (Groupe Speciale Mobile) is a digital cellular mobile radio system that services millions of customers and covers almost all European countries (R. Steele, 1995; N.J. Muller, 1995). It has a hierarchical structure, which consists of a number of base station controllers (BSCs) at the lower level, which are connected to a number of mobile switching centers (MSCs). MSCs are responsible for routing a call from the BSC that made the request, to the BSC that will receive the call. The routing of a call is done either through the Public Switched Digital Network (PSDN) or through the MSCs themselves. BSCs and MSCs form a mesh network, called GSM Infrastructure Network (GIN), that is based on medium and/or high speed point-to-point links. During the design phase of the inter-networking devices of such a GIN, the selection of the proper routing algorithm becomes the main issue. The article presents the model of such a GIN network, a model of its traffic sources, the network topology and the functionality of its nodes. Simulation studies are presented for determining how various routing algorithms affect network performance. Based on these results, the best routing algorithm for such an application is specified