Efficient heuristic algorithms for finding multi-constrained paths

Quality of service routing, namely, finding multi-constrained paths is a real problem arising in multimedia applications, which has been proven to be NP-complete. The paper presents three polynomial-time scalable algorithms for finding a path subject to two additive constraints: one to be a randomized algorithm and two to be limited path heuristic algorithms. To our best knowledge, so far, the best heuristic algorithm among the existing algorithms is Korkmaz´s algorithm. However, from our simulations, our algorithms may achieve not only better performance than Korkmaz´s algorithm, but also as good performance as the exact algorithm which searches exhaustively all possible paths in the graph to determine whether there exists a solution or not.