Efficient Method for Link Protection Under Multiple Constraints Using ZDD

Abstract

It is an important issue to design a highly reliable information network that is robust against network failures. As a method for design of a robust network, there is an approach of protection, which decreases link failure probability by backup mechanism and fast recovery mechanism. It is desirable to protect all links; however, link protection needs much cost. Therefore, it is necessary to find the small number of links to be protected so that a network resulting from failure of any non-protected links satisfies constraints of quality. In this paper, we propose a method to design an information network satisfying multiple constraints by using an efficient data structure, Zero-suppressed Binary Decision Diagram (ZDD). This method holds the set of the feasible solutions satisfying each constraint by ZDD, and it determines the intersection of the sets of the feasible solutions for all constraints by the calculation of ZDD. Thus, the method can determine the sets of the feasible solutions satisfying the multiple constraints simultaneously, and finally it determines the optimum solution. This approach also makes it easy to change or to add constraints.