Multicast wavelength routing and assignment under multi-drop path model

We investigate the problem of Wavelength Minimization for Multicast Traffic under Multi-drop Path Model (WMMT-MPM) in all-optical networks. Under a multi-drop path model, multiple paths are employed to establish a multicast session and each path can drop signals at no more than a predefined number of destination nodes. Given a network topology and a set of multicast sessions, the WMMT-MPM problem is to find a valid routing for each of the multicast sessions and assign a wavelength to each path in each of the routings, with the objective of minimizing the total number of wavelengths used to establish all the multicast sessions. To effectively solve the WMMT-MPM problem, we develop two heuristics for routing and wavelength assignment: MFBH-SL and TSH. Through experiments, we show that the TSH outperforms MFBH-SL in more than 80% of instances for real-life and randomly generated networks. Furthermore, the percentage of wavelength saving is at least 18% when session size is ≤ 40% of network nodes.