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The survivable logical topology routing problem for a given IP-over-WDM network is to map each logical link into a lightpath in the physical network which guarantees connectivity of the IP network after any physical link failure. Such a survivable routing is said to protect the logical network against all single physical link failures. But, it is possible that a logical topology may not admit a survivable...
We propose a linear formulation based on Mixed-Integer Linear Programming (MILP) for efficiently designing Spectrum-Sliced Elastic Optical Path Networks (SLICE) under traffic Grooming. The formulation minimizes the spectrum utilization when the total number of transceivers are limited and taken as a constraint. The results suggest that the proposed model provides a tool to analyse the compromise between...
The demands mixed with the coarse and fine granularity cause the poor resource utilization and the port thirsty of previous grooming techniques in Wavelength-Division-Multiplexing (WDM) optical networks. Furthermore, with the large scale of the backbone, the optical network has been divided into multiple domains to achieve the scalability in the real world. In this paper, we study the gra-diversity...
This article evaluates the performance of Wavelength Division Multiplex (WDM) networks considering two different modes of photonic Switching: Optical Packet Switching (OPS) and Optical Circuit Switching (OCS). A resource distribution planning is proposed including wavelength/amplifier allocation to improve the blocking probability and to ensure signal quality. The present study considered the effects...
Cognition represents one of the ingredients to make up the future high-capacity heterogeneous optical networks. This paper provides three main contributions for a preliminary study of a Control and Management System (CMS) able to support the cognitive entity, named Cognitive Decision System (CDS). First of all, two architectural approaches to realize a cognitive optical network are presented. Secondly,...
In this paper we present a method for optimal planning of bidirectional optical packet-switched rings, with synchronized work of ring stations and an out-of-band control channel. The network stations are equipped with tunable transmitters and fixed single-wavelength receivers that can be shared by different destinations and without a limit on their number per destination. Optimal planning method that...
In previous work, we investigated the optimization of physical topology design so that the total operational and embodied energy is minimized under normal operation. However, the loss of any link, through for example a fiber cut or the loss of a node, may result in a higher energy consumption as the traffic will be re-routed over the remaining links of the network. In this paper we identify the impact...
As networks continue to expand, energy consumption is increasingly becoming a major issue, affecting not only the operational costs, but also the associated emission of greenhouse gasses (GHG). Thus, reducing power consumption, as well as GHGs (primarily CO2) to reduce the carbon footprint of the network, has started to play a significant role in network planning. In networks with both renewable and...
We have addressed synchronisation of optical packet switched network on a mesh topology. The focus here is the synchronisation architecture for the optical packets in TWIN based network. The optical packets from different sources are passively groomed on one wavelength with a central control/management plane. In order to provide the necessary precise synchronisation system between the central control...
In future flexgrid core networks the amount of lightpaths might increase significantly as a consequence of the finer granularity in the use of the optical spectrum. Different spectrum bandwidth can be allocated to each lightpath as a function of, among others, the bitrate amount to be conveyed and the modulation format used. As result, spectrum fragmentation might appear leading to non-optimal resource...
We consider the virtual topology and traffic routing (VTTR) problem, a subproblem of traffic grooming that arises as a fundamental network design problem in optical networks. The objective of VTTR is to determine the minimum number of light-paths so as to satisfy a set of traffic demands, and does not take into account physical layer constraints; a routing and wavelength assignment (RWA) algorithm...
The orthogonal frequency division multiplexing (OFDM) technology provides an opportunity for efficient resource utilization in optical networks. It allows allocation of multiple sub-carriers to meet traffic demands of varying size. Utilizing OFDM technology, a spectrum efficient and scalable optical transport network called SLICE was proposed recently. The SLICE architecture enables sub-wavelength,...
This paper introduces a novel traffic grooming algorithm for the connection establishment of deadline-driven requests. The algorithm grooms batches of requests rather than individual requests. Results indicate that the algorithm is able to significantly reduce the blocking ratio and promote a fair distribution of blocking among source destination pairs of nodes.
Virtualization improves the efficiency of networks by allowing multiple virtual networks to share a single physical network's resources. Next-generation optical transport networks are expected to support virtualization by accommodating multiple virtual networks with different topologies and bit rate requirements. Meanwhile, Optical Orthogonal Frequency-Division Multiplexing (OOFDM) is emerging as...
We propose a novel dynamic transparent virtual network embedding (VNE) algorithm, which considers node mapping and link mapping jointly, for network virtualization over optical orthogonal frequency-division multiplexing (O-OFDM) based elastic optical infrastructures. For each virtual optical network (VON) request, the algorithm first transfers the substrate optical network into a layered-auxiliary-graph...
Network coding has been recently proposed as a proactive network protection scheme. Its main objective is to improve the resilience of wired networks against link failures in a proactive manner, while simultaneously providing network resource savings (IP bandwidth, optical wavelengths) compared to traditional protection schemes. Warned by the potential network coding might bring as well as by the...
The orthogonal frequency division multiplexing (OFDM) technology provides an opportunity for efficient resource utilization in optical networks. It allows allocation of multiple sub-carriers to meet traffic demands of varying size. Utilizing OFDM technology, a spectrum efficient and scalable optical transport network called SLICE was proposed recently. The SLICE architecture enables sub-wavelength,...
In this paper, we review OpenFlow-based control and management technology for optical networks including multi-layer optical networks, multi-domain optical networks and elastic optical networks. We also present the interworking between OpenFlow and PCE/GMPLS control planes.
We investigate what kind of information should be exchanged for controlling multiple VNTs. Simulation results show number of reconfigurations to find good VNTs is significantly reduced with slightly increased, but still marginal, amount of information.
Cognitive networks are a promising solution for the control of heterogeneous optical networks. We review their fundamentals as well as a number of applications developed in the framework of the EU FP7 CHRON project.
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