An improved smart edge removal light-hierarchy multicast routing algorithm for optical networks

The light-hierarchy structure has been proved as the optimal solution with minimum cost for all-optical multicast routing with sparse splitting constraint. Edge Removal Light-Hierarchy (ERLH) algorithm is the most common algorithm to compute a light-hierarchy. However, it has poor link blocking and wavelength resources utilization performance. An improved Edge Removal Light-Hierarchy named Smart ERLH (S-ERLH) algorithm is proposed for multicast routing in spare splitting WDM networks, which can adjust the routing strategy dynamically according to network traffic load conditions, and decrease the blocking probability. Theoretical analysis and numerical simulations show that the improved S-ERLH algorithm has better blocking probability than traditional ERLH in most traffic load scenarios.