دانلود رایگان مقاله الگوریتم های مسیریابی چندپخشی برای شبکه نوری تقسیم اسپارس

Abstract

This work proposes novel routing approaches for transparent optical networks where only a fraction of the network nodes are multicast capable (MC) and can split the optical power from a single input to multiple output ports. The remaining, multicast-incapable (MI) nodes, can have either Drop-or-Continue (DoC) or Drop-and-Continue (DaC) capabilities. For the case of DaCs, if a MI node is a destination of the multicast group, it can drop a fraction of the incoming signal locally and transmit the rest to the next node. The current paper presents an Integer Linear Programming (ILP) formulation as well as novel heuristic multicast routing algorithms under the sparse-splitting constraint, for networks with or without DaC nodes. Performance results show that the proposed algorithms achieve an important decrease of the average cost of the derived solutions, compared to existing relevant techniques, and attain results very close to the lower bound provided by the ILP.

7. Conclusions

 In the current paper, the problem of multicast routing for net- works with sparse-splitting capabilities was investigated, for net- works where the MI nodes are either DoC or DaC. A novel Integer 972 Linear Programming formulation was presented for both types of net- 973 works, as well as novel multicast routing heuristic algorithms under the sparse-splitting constraint. Simulations on the USNET, NSFNET, 975 as well as on several randomly created networks, have shown that the proposed algorithms achieve an important decrease of the av- erage cost of the derived solutions, compared to existing relevant techniques. For the USNET and NSFNET networks the performance of SSMRH is very close to the lower bound provided by the ILP, leaving 980 very little room for any further improvement. Specifically, for these 981 networks, the proposed algorithms obtain the optimal solution for the majority of the investigated cases. 983 Future work focuses on the development of a novel Integer Lin- ear Programming formulation as well as heuristic algorithms that can provide survivable multicast routing in sparse-splitting optical net- works.