Hai-Chau Le

Hierarchical Optical Path Network Design Algorithm Considering Waveband Add/Drop Ratio Constraint

A new hierarchical optical path network design algorithm that incorporates restrictions on waveband add/drop ratios at nodes is proposed. We evaluate its effectiveness by conducting extensive numerical experiments. The effects of the network parameters, which include network size, link distance, and network topology, on total network cost are elucidated. The results show that the proposed algorithm, which considers restrictions on the waveband add/drop ratio, yields almost the same cost as an algorithm that does not consider the add/drop ratio when the ratio is not so stringent, say, greater than 0.3. It is also demonstrated that choosing the waveband capacity properly is critical in minimizing total network cost.

Performance evaluation of large-scale multi-stage hetero-granular optical cross-connects.

We proposed generalized large-scale two-stage-routing OXC architectures and evaluated the performance possible with the use of small-degree WSSs and simple optical devices; 1 x n switches or WBSSs. Numerical evaluations verify that the new architectures reduce necessary hardware scale substantially at the cost of few additional fibers while their effectiveness increases with the traffic demand. The tradeoff between the link resource increase and the hardware scale reduction is also clarified.

Hybrid hierarchical optical path network design algorithm with 2-stage ILP optimization

We propose a 2-stage ILP-based design algorithm for hybrid-HOXCs based optical networks. The hybrid-HOXC consists of an optical waveband cross-connect and an electrical cross-connect which grooms only wavelength paths. Its effectiveness is evaluated through numerical experiments. Impact of electrical/optical port cost ratio on the total network cost is also investigated.

Impact of electrical grooming and regeneration of wavelength paths in creating hierarchical optical path networks

We assess the impact of a hybrid hierarchical optical path network that utilizes electrical cross-connects for intermediate grooming and 3R regeneration of wavelength paths. Simulation results proved that it offers up to 60% cost reduction.

Hierarchical optical path network design algorithm that can best utilize WSS/WBSS based cross-connects

In order to reduce cross-connect switch scale by utilizing the WSS/WBSS based hierarchical cross-connect switch architecture, we propose a novel network design algorithm that satisfies a restriction on add/drop ratio for each waveband. The effectiveness of the proposed algorithm is proven by numerical experiments.

Cost evaluation of hybrid-hierarchical optical cross-connects based optical path networks

In this paper, we present a hybrid-hierarchical optical cross-connect (hybrid-HOXC) architecture that employs a waveband cross-connect for adding/dropping or routing waveband paths and an electrical cross-connect to grooming wavelength paths. Then, we have proposed a heuristic design algorithm for the hybrid-HOXCs based optical path networks. Its effectiveness is evaluated through numerical experiments with different traffic loads and network parameters.

Large capacity optical networks applying multi-stage hetero-granular optical path routing

We propose a novel scalable large-scale OXC architecture with a two-stage hetero-granular optical path switching mechanism based on a combination of different granular optical selective switches and an appropriate network design algorithm that can make the best use of the proposed OXC architecture for building cost-effective large capacity optical networks. Simulation results verify that our proposed solution can offer a significant overall network cost reduction. The cost efficiency of networks based on the architecture is also investigated in relation to switching component cost and different network parameters.

Hybrid optical WDM networks utilizing optical waveband and electrical wavelength cross-connects

We propose an optical waveband and electrical OTN hybrid-HOXC node configuration, and a suitable network design algorithm. The proposed hybrid-HOXC network is verified as being very cost effective over a wide range of parameter values.

Hybrid-hierarchical optical path network design algorithms utilizing ILP optimization

Abstract In this paper, we present design algorithms for the hierarchical optical path networks that utilize hybrid-hierarchical optical cross-connects (hybrid-HOXCs). The hybrid-HOXCs employ a waveband cross-connect for routing waveband paths and an electrical cross-connect for grooming wavelength paths. We first develop an integer linear programming model to solve the network design problem. We then propose a 2-stage ILP-based design algorithm for hierarchical optical path networks that utilize the hybrid-HOXCs. Its effectiveness is evaluated through numerical experiments. Impact of the critical parameter, electrical/optical port cost ratios, on total network cost is also investigated.

A comparison of large-scale selective switch-based optical cross-connects

We compare the performance of three notable selective switch-based large-scale ROADM/OXC architectures that can make the best use of existing optical switch technologies for realizing bandwidth-abundant optical networks. We then analyze the tradeoff between node routing flexibility and hardware scale requirement in selective switch-based ROADM/OXC networks. The impact of WSS/WBSS degree on the network performance and the efficient WBSS cost bound are also evaluated.