The Ring-Loading and Ring-Sizing Problem

Ring based structures axe often desirable in telecommunication networks since they offer a structure which is inherently fault-tolerant. The simplest such structure consists of a set of nodes connected by links to form a simple cycle. This simple configuration provides high survivability since every pair of nodes is connected by a physically diverse route, and hence no single link failure will disconnect the ring. In the event of failure, all traffic can be diverted as long as the ring has enough capacity. The ring sizing problem is then to determine the minimum capacity to handle all traffic while guaranteeing fault protection. In order to solve this problem, the traffic on the ring has to be routed in such a way as to minimise the maximum load on any link, this is termed the ring loading problem. In this paper we apply both a genetic algorithm and a simulated annealing algorithm to solve this problem.