Traffic-Grooming in WDM Network under Physical Constraints

Virtual topology design is an efficient approach to tackle the traffic-grooming problem which multiplexes low-granularity demands into high-granularity pipes in optical networks. But it is hard to deal with the demands with various physical constraints. In this paper, we propose a packing grooming with partial-combination algorithm (PPA) to address this issue. The PPA first routes low-granularity demands one by one to satisfy their own constraints, and then packs these low-granularity demands into multiple-hop potential high-granularity pipes in physical network to save the low-granularity switch capacity in the intermediate nodes. With the high-granularity potential pipes in hand, we use a partial-combination approach to identify the set of potential pipes with the maximum revenue which do not collide with each other and instantiate them. Numerical results show that PPA has better performance than existing algorithms, and it could be used to solve this problem in large networks with more than one hundred nodes.