Calculation of arc-disjoint trees in mixed-graph arbitrary mesh optical networks

In the paper, a heuristic algorithm that deals with the problem of finding arc-disjoint trees in mixed-graph mesh optical networks is presented. A mixed graph is defined as one that has both unidirectional and bidirectional links between its nodes. The calculation of pairs of arc-disjoint trees is applied for provisioning survivable multicast requests. The development of algorithms that work efficiently for this kind of networks is important, since in practice the network is modeled as a mixed graph. Simulations show that for the case of mixed-graph networks, the proposed multicast protection algorithm is able to calculate arc-disjoint tree pairs with lower blocking ratio and average cost compared to the existing algorithms, especially for multicast sessions with destination sets that comprise of up to half of the network nodes.