An optimal deployment strategy for ISDN switches in metropolitan networks: modeling and algorithm

In the initial stage of ISDN, ISDN switches (hosts) are installed in the main areas and the other areas are covered by remote systems. As the number of subscribers of a remote system increases this remote system will be replaced with a host, considering costs of hosts and remote systems. We formulate the problem of finding an optimal deployment strategy of ISDN facilities, mainly switch and remote systems, over a planning horizon using an integer programming and develop a heuristic algorithm for the problem. The heuristic algorithm developed here uses a backward approach from the final time of the planning horizon and can be efficiently implemented for determining the ISDN switch installation time.