The Potential of Optical Layer Networks

IEEE/ACM Trans. Networking

2005

100

Abstract-The static provisioning problem in wavelength-routed optical networks has been studied for many years. However, service providers are still facing the challenges arising from the special requirements for provisioning services at the optical layer. In this paper, we incorporate some realistic constraints into the static provisioning problem, and formulate it under different network resource availability conditions. We consider three classes of shared risk link group (SRLG)-diverse path protection schemes: dedicated, shared, and unprotected. We associate with each connection request a lightpath length constraint and a revenue value. When the network resources are not sufficient to accommodate all the connection requests, the static provisioning problem is formulated as a revenue maximization problem, whose objective is maximizing the total revenue value. When the network has sufficient resources, the problem becomes a capacity minimization problem with the objective of minimizing the number of used wavelength-links. We provide integer linear programming (ILP) formulations for these problems. Because solving these ILP problems is extremely time consuming, we propose a tabu search heuristic to solve these problems within a reasonable amount of time. We also develop a rerouting optimization heuristic, which is based on previous work. Experimental results are presented to compare the solutions obtained by the tabu search heuristic and the rerouting optimization heuristic. For both problems, the tabu search heuristic outperforms the rerouting optimization heuristic.Index Terms-Capacity minimization problem, dedicated-path protection, revenue maximization problem, shared-path protection, shared risk link group (SRLG), tabu search, wavelength-routed optical network.

Section: Resultsmentioning

confidence: 99%

Shared risk link Group (SRLG)-diverse path provisioning under hybrid service level agreements in wavelength-routed optical mesh networks

Shen

IEEE/ACM Trans. Networking

2005

100

“…As surveyed by [8], the ordinarily used 600 km reach distance for transparent optical signals is far from the requirement for today's Internet traffic. Even a reach distance of 3000 km can only satisfy 60% of the connections.…”

Section: B Other Relevant Work 1) Sparse Regenerationmentioning

confidence: 99%

“…If the numbers of traversed optical links are equal, those with higher IPT values are discarded (see Section IV-C4 for information on how to compare two IPTs). When the destination is reached by an explored route, the IPT values are tested using the constraint inequalities (3) and (8) or (4) and (9), depending on whether access/regeneration or optical bypass is carried out. Finally, the route with the least number of optical links (or lowest IPT values if the numbers of optical links are equal) is selected among all the routes that have passed the test.…”

Section: A Olc-bfs Proceduresmentioning

confidence: 99%

Dynamic routing in translucent WDM optical networks: the intradomain case

2005

J. Lightwave Technol.

Abstract-Translucent wavelength-division multiplexing optical networks use sparse placement of regenerators to overcome physical impairments and wavelength contention introduced by fully transparent networks, and achieve a performance close to fully opaque networks at a much less cost. In previous studies, we addressed the placement of regenerators based on static schemes, allowing for only a limited number of regenerators at fixed locations. This paper furthers those studies by proposing a dynamic resource allocation and dynamic routing scheme to operate translucent networks. This scheme is realized through dynamically sharing regeneration resources, including transmitters, receivers, and electronic interfaces, between regeneration and access functions under a multidomain hierarchical translucent network model. An intradomain routing algorithm, which takes into consideration optical-layer constraints as well as dynamic allocation of regeneration resources, is developed to address the problem of translucent dynamic routing in a single routing domain. Network performance in terms of blocking probability, resource utilization, and running times under different resource allocation and routing schemes is measured through simulation experiments.Index Terms-Dynamic routing, physical impairments, regeneration, routing and wavelength assignment (RWA), signal quality constraints, translucent optical network, wavelength-division multiplexing (WDM).

“…As surveyed by [6], the ordinarily used 600 Km span distance is far from the requirement by today's Internet traffic. Even a reach distance of 3000 Km can only satisfy 60% of the connections.…”

Section: Review Of Relevant Studymentioning

confidence: 99%

Dynamic routing in translucent WDM optical networks

2002 IEEE International Conference on Communications. Conference Proceedings. ICC 2002 (Cat. No.02CH37333)

Abstract-Translucent WDM optical networks use sparse placement of regenerators to overcome the impairments and wavelength contention introduced by fully transparent networks, and achieve a performance close to fully opaque networks with much less cost. Our previous study proved the feasibility of translucent networks using sparse regeneration technique. We addressed the placement of regenerators based on static schemes allowing only fixed number of regenerators at fixed locations. This paper furthers the study by proposing a suite of dynamical routing schemes. Dynamic allocation, advertisement and discovery of regeneration resources are proposed to support sharing transmitters and receivers between regeneration and access functions. This study follows the current trend in optical networking industry by utilizing extension of IP control protocols. Dynamic routing algorithms, aware of current regeneration resources and link states, are designed to smartly route the connection requests under quality constraints. A hierarchical network model, supported by the MPLS-based control plane, is also proposed to provide scalability. Experiments show that network performance is improved without placement of extra regenerators.