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Routing and wavelength assignment is the important problem to multi-domain ASON. In order to solve this problem, a new impairment-aware routing algorithm based on colored graph model (IRACM) is proposed in this paper. In the proposed algorithm, different ant colonies different and different mechanisms of pheromone control, and the local search and global search are used. The analysis shows that the...
As the distributed multi-domain DWDM optical network has been advocated to be the next generation optical network, there is a pressing need to address the inter-domain RWA (Routing and wavelength assignment) problem. Thus, we propose a set of new inter-domain RWA schemes, including a MLP (Most leisure path) routing strategy based on the Hybrid abstraction and a ID-MU (Inter-domain most used) wavelength...
A novel routing architecture that balances incoming traffic over the Agile All-Photonic Network (AAPN) is proposed. The architecture is based on the adaptive highest random weight (Adaptive HRW) algorithm proposed to design load balanced internet routers. It extends the adaptive HRW algorithm by assigning balancing weights to each source-destination edge node pair in the network. The weights are adapted...
With new optical transport systems able to provide sub-wavelength granularity, the dynamic characteristics of the network are expected to strongly increase. Furthermore, such properties are highly related to the underlying physical network topology, which in turn require from the control plane important features such as scalability, dynamism and automatism. In this paper we analyze the properties...
Transparent optical networks based on wavelength division multiplexing (WDM) can exploit the huge capacity of optical fibers by dividing it among different wavelengths. Physical-layer attacks, such as high-powered jamming, can seriously degrade network performance and must be dealt with efficiently. Hence route lightpaths in such a way as to minimize the potential damage caused by various physical-layer...
In transparent optical networks, the signal is directly switched in the optical domain without o-e-o regeneration. When considering high bit rate transmissions, uncompensated Chromatic Dispersion (CD) and Amplified Spontaneous Emission (ASE) noise accumulate along the fibers causing inter symbol interference and OSNR degradation. As a result, several connection requests are blocked for the low signal...
Optical Transport Network (OTN) is a standard approach to offering transport support to a variety of existing service technologies, e.g., ESCON, HDTV, GE, etc. Multiple service technologies can be concurrently multiplexed onto one common transport network, which offers hierarchical transmission rate wrappers physically supported by Wavelength Division Multiplexing (WDM) lambda channels. Algorithms...
Optical network design problems fall in the broad category of network optimization problems. We give a short introduction on network optimization and general algorithmic techniques that can be used to solve complex and difficult network design problems. We apply these techniques to address the static Routing and Wavelength Assignment problem that is related to planning phase of a WDM optical network...
Routing and Wavelength Assignment (RWA) problem in Wavelength Division Multiplexed (WDM) optical networks assumes assigning the routes and wavelengths to be used to create the lightpaths on behalf of the connection requests. The RWA problem belongs to the class of combinatorial optimization problems. The optimal solution to the RWA problem is found to be NP-hard and thus suited to heuristic approaches...
Link-disjoint routing strategy can offer a set of reliable alternate paths when the active best path fails. However, simply employing a set of fully disjointed paths may not necessarily result in the efficient network resource utilization in some circumstances, which degrades the performance of the network system under a highly loaded traffic condition. In this study, we propose two heuristic link-disjoint...
We consider, for the first time, the problem of flexible/open wavelength assignment and propose an optimal as well as heuristic solution. Simulation results validate our solution to within 15% of the theoretical spectral limit.
We show that blocking in dynamic networks of colorless, non-directional ROADMs is tolerant to intra-node contention when contention-aware routing/wavelength assignment (RWA) algorithms are used. An optional client-side cross-connect enables low blocking with simpler RWA variants.
We propose a novel outer-ROADM-ring (ORR) based multi-domain routing scheme in optical WDM networks. Results show that this scheme has both high scalability and low blocking probability, while preserving inter-domain confidentiality as well.
A Wavelength-Aware approach for Translucent design and dynamic routing is presented. Compared to the Wavelength-UnAware worst-case design scenario, up to 100% reduction on OEO interfaces has been found.
Optical routing technologies will surely be the key to creating future bandwidth abundant and green networks. Considering future services and the need to create virtual fiber networks, the introduction of wavebands is a next important step.
We propose dynamic routing and spectrum assignment algorithms for bitrate-flexible lightpaths in OFDM-based optical networks. The novel algorithms enable dynamic spectrum assignment with more efficient resource utilization and less traffic blockings.
A temporary resource reservation mechanism can enhance the performance of a stateless PCE in situations when the TED might not be up-to-date. This paper examines the benefits of such a mechanism by means of simulation.
A multi-layer grooming and routing method, which considers the optical layer constraints, is proposed. This method, based on a new modeling, allows significant resource saving with respect to a layer by layer approach.
Ever increasing demand for more bandwidth over the Internet has lead to the development of many new technologies and architectures. Among these, Hybrid of Wireless and Optical networks have become increasingly important because of their “mobility” and “flexibility” in the wireless part and “robustness” and “high capacity”...
One of the main challenges in optical networking is the problem of Routing and Wavelength Assignment (RWA). Generally speaking, the algorithms proposed for RWA are divided into two categories: Centralized and Distributed. According to the scale, size and other preferences of a network, one of the above strategies can be selected for establishing lightpaths in the network. In small size networks where...
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