Abstract: A method is described for route computation in Communications Networks with multiple QoS metrics. This method takes a metric (say, cost) as an optimization target and the other metric (say, delay) as a constraint. A communication network with multiple QoS metrics associated to its links is modelled as a graph with multiple QoS metrics as weights associated to its links. The method associates constraints with nodes in the graph after generating a minimum spanning tree based at a destination node using Dijkstra's algorithm with the constraint metric as link weight. A set is populated with nodes whose path to the destination node satisfies given constraints while endeavouring to optimize another QoS metric. A path may be computed by selecting, from the set, the destination node and associated predecessor nodes through to the start node. The algorithm of the method is very efficient and its computational complexity is O(n2).

Abstract: A method is described for one-to-all route selection in Communications Networks with multiple QoS metrics. This method takes a first metric (say, delay) as a constraint and a second metric (say, cost) as an optimization target. A potential objective is to find a path between a source node and each node in a communications network such that the delay of the path does not exceed a path delay constraint and the cost of the path is minimized. The method selects a first path which is a shortest path from a source node to each node in terms of the first metric using Dijkstra's algorithm. A reachability graph is then constructed based on the first metric path constraint. Within the reachability graph, another path is found, which is a shortest path from a source node to each node in terms of the second metric, using Dijkstra's algorithm. Any path to a particular node selected within the reachability graph replaces the first path to said particular node.