On Network Augmentation

A network often has to be augmented either to improve the services offered or to improve the reliability of the network. If reliability is to be enhanced by adding a link across one of the pairs of its nodes, one needs to select the appropriate pair to achieve maximum gain in reliability. The obvious choice is the source-, terminal-node pair. But such an installation may not be possible due to terrain conditions or large distance between source-, terminal-node which makes installing such a link very expensive and time consuming. A heuristic method is proposed to compare the reliability gains for other different pairs of nodes and hence to select the best pair out of given pairs. The method has been verified and is illustrated with an example. In most cases, it gives correct results or the error in unimportant.