Thesis or Dissertation Routing and Wavelength Assignment Schemes in Scalable Wavelength-Routed Optical Networks

パワランクン, プラパン  ,  パワランクン, プラパン  ,  Pavarangkoon, Praphan

pp.1 - 129 , 2015-09-30 , The University of Electro-Communications
The exponential growth of the bandwidth demand for data transmission capacity has made an optical network a promising candidate for the future core network architecture. A wavelength-routed optical network (WRON) has the potential to meet rising demands for high bandwidth and low latency communication. In conventional WRON, it is more difficult to manage optical carriers as the number of wavelengths increases. In addition, it is difficult to manage the entire network with full knowledge of network resources on single-domain scenarios. In order to make the conventional WRON more scalable and manageable, researches on optical carrier management for metro/regional networks and domain-level partitioning for large-scale optical networks are conducted. Accordingly, wavelength reusable multi-carrier-distributed (WRMD) network is able to simplify the optical carrier management by placing a multi-carrier light source (MCLS) in an MCLS node, as the communication light source device. In order to utilize network resources efficiently, a large network that is partitioned into several domains, called multi-domain network, can take place. In this thesis, RWA schemes in WRMD network and multi-domain network are introduced. In the WRMD network, a routing and wavelength assignment (RWA) scheme is considered. The RWA scheme in the WRMD network must take into account both optical carrier connections and requested lightpaths using the reuse of the optical carrier connections while minimizing the number of required wavelengths. There are two investigated cases, depending on the number of MCLS nodes: either one or multiple. First, the RWA problem is formulated as the integer linear programming (ILP) problem of obtaining the minimum number of required wavelengths to satisfy the given lightpath setup requests. For large-scale networks, the ILP approach is not practical solution times. A heuristic RWA scheme is then introduced to solve the RWA problem in practical times. In the multi-domain optical network, a survivable RWA scheme, which provides complete end-to-end primary and backup path pairs, is considered. In this thesis, the survivable lightpath provisioning scheme that allows traffic splitting to minimize the cumulative cost of a set of paths is introduced. This scheme employs an ILP formulation based on hierarchical path computation with full-mesh topology abstraction. There are two phases in the scheme. The first phase solves the ILP problem on an inter-domain topology and then feeds the results as intra-domain requests. The second phase solves the ILP problem in each related domain. Finally, all the intra-domain solutions are concatenated along routing sequences. Moreover, three different protection strategies, namely same domain sequence, link disjoint, and domain disjoint, are considered with varying degrees of primary and backup route separation. The performance of the RWA schemes in each network is evaluated in many points as well as many different network topologies. Therefore, the schemes can provide reference values to gauge the existing distributed heuristics and to further analysis.

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