| 1. |
- Abedifar, Vahid, et al.
(författare)
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Routing, Modulation and Spectrum Assignment in Programmable Networks based on Optical White Boxes
- 2018
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Ingår i: Journal of Optical Communications and Networking. - : Optical Society of America. - 1943-0620 .- 1943-0639. ; 10:9, s. 723-735
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Tidskriftsartikel (refereegranskat)abstract
- Elastic optical networks (EONs) can help overcome the flexibility challenges imposed by emerging heterogeneous and bandwidth-intensive applications. Among the different solutions for flexible optical nodes, optical white box switches implemented by architecture on demand (AoD) have the capability to dynamically adapt their architecture and module configuration to the switching and processing requirements of the network traffic. Such adaptability allows for unprecedented flexibility in balancing the number of required nodal components in the network, spectral resource usage, and length of the established paths. To investigate these trade-offs and achieve cost-efficient network operation, we formulate the routing, modulation, and spectrum assignment (RMSA) problem in AoD-based EONs and propose three RMSA strategies aimed at optimizing a particular combination of these performance indicators. The strategies rely on a newly proposed internal node configuration matrix that models the structure of optical white box nodes in the network, thus facilitating hardware-aware routing of connection demands. The proposed strategies are evaluated in terms of the number of required modules and the related cost, spectral resource usage, and average path length. Extensive simulation results show that the proposed RMSA strategies can achieve remarkable cost savings by requiring fewer switching modules than the benchmarking approaches, at a favorable trade-off with spectrum usage and path length.
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| 2. |
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| 3. |
- Abeywickrama, S., et al.
(författare)
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Dual-homing based protection for enhanced network availability and resource efficiency
- 2014
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Ingår i: Asia Communications and Photonics Conference, ACP. - Washington, D.C. : Optica Publishing Group.
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Konferensbidrag (refereegranskat)abstract
- An approach to enhance core network survivability by utilizing dual-homing capabilities of the access network. Results reveal significant improvements in core network resource utilization and connection availability, suggesting benefits to network operators and service providers.
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| 4. |
- Abeywickrama, S., et al.
(författare)
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Energy-efficient survivability for core networks using dual-homing
- 2015
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Ingår i: Asia Communications and Photonics Conference, ACPC 2015. - Washington, D.C. : OSA. - 9781943580064
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Konferensbidrag (refereegranskat)abstract
- This paper studies the energy efficiency of exploiting dual-homing in access network to provide core network survivability. Simulation results show reduced number of utilized wavelengths, suggesting significant energy saving opportunities in the core network.
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| 5. |
- Abeywickrama, Sandu, et al.
(författare)
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Protecting core networks with dual-homing: A study on enhanced network availability, resource efficiency, and energy-savings
- 2016
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Ingår i: Optics Communications. - : Elsevier. - 0030-4018 .- 1873-0310. ; 381, s. 327-335
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Tidskriftsartikel (refereegranskat)abstract
- Core network survivability affects the reliability performance of telecommunication networks and remains one of the most important network design considerations. This paper critically examines the benefits arising from utilizing dual-homing in the optical access networks to provide resource-efficient protection against link and node failures in the optical core segment. Four novel, heuristic-based RWA algorithms that provide dedicated path protection in networks with dual-homing are proposed and studied. These algorithms protect against different failure scenarios (i.e. single link or node failures) and are implemented with different optimization objectives (i.e., minimization of wavelength usage and path length). Results obtained through simulations and comparison with baseline architectures indicate that exploiting dual-homed architecture in the access segment can bring significant improvements in terms of core network resource usage, connection availability, and power consumption.
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| 6. |
- Abtahi, Farzad, et al.
(författare)
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Optimal Design of Cost- and Energy-Efficient Scalable Passive Optical Backbone Networks
- 2012
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Ingår i: 2012 Asia Communications And Photonics Conference (ACP). - Washington, D.C. : OSA. - 9781467362740 ; , s. AS3D.4-
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Konferensbidrag (refereegranskat)abstract
- We propose an optimization model minimizing number of wavelengths in passive optical backbone networks and obtaining the same resource usage as in networks based on active switching while reducing both cost and power consumption.
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| 7. |
- Ahmed, Jawwad, et al.
(författare)
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A Dynamic Bulk Provisioning Framework for Concurrent Optimization in PCE-Based WDM Networks
- 2012
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Ingår i: Journal of Lightwave Technology. - : IEEE. - 0733-8724 .- 1558-2213. ; 30:14, s. 2229-2239
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Tidskriftsartikel (refereegranskat)abstract
- A centralized network control and management plane, such as the one based on a path computation element (PCE), is highly beneficial in terms of resource optimization in wavelength division multiplexing optical networks. Benefits of centralized provisioning are even more evident when connection requests are provisioned in batches, i.e., they allow a better use of network resources via concurrent optimization. In this study, a dynamic bulk provisioning framework is presented with the objective of optimizing the use of network resources that also presents, as an additional benefit, the ability to yield a reduction of the control plane overhead. The rationale behind the proposed framework is based on a mechanism in which the PCE client is allowed to bundle and simultaneously send multiple labeled switch path (LSP) requests to the PCE where, in turn, several bundles can be concurrently processed together as a single bulk. From the network deployment perspective, a PCE-based network architecture is proposed to practically realize this approach. For dynamic bulk provisioning of optical LSP requests, a time-efficient integer linear programming (ILP) model (LSP BP ILP) is presented to minimize the request blocking, the network resource consumption, and the network congestion. In addition, a heuristic based on a greedy randomized adaptive search procedure (GRASP), namely LSP_BP_GRASP, is also proposed as a scalable alternative. The presented results demonstrate significant advantages of the proposed PCE bulk provisioning framework based on concurrent optimization in terms of reduced blocking probability and control overhead when compared with conventional dynamic connection provisioning approaches processing a single connection request at a time.
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| 8. |
- Ahmed, Jawwad, et al.
(författare)
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An Optimal Model for LSP Bundle Provisioning in PCE-based WDM Networks
- 2011
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Ingår i: 2011 Optical Fiber Communication Conference and Exposition and the National Fiber Optic Engineers Conference, OFC/NFOEC 2011. - Washington : Optical Society of America.
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Konferensbidrag (refereegranskat)abstract
- A time-efficient resource optimization model for dynamic concurrent provisioning of connection requests at PCE is proposed. It is shown that a significant performance improvement can be achieved without noticeable increase in connection setup-time.
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| 9. |
- Ahmed, Jawwad, et al.
(författare)
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Benefits of Connection Request Bundling in a PCE-based WDM Network
- 2009
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Ingår i: Proc. of European Conference on Networks and Optical Communications (NOC).
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The Path Computation Element (PCE) concept is considered to be beneficial in the network connection setup operations, especially in optical networks based on wavelength division multiplex (WDM) transport technology. In the PCE paradigm, communication between a node and the PCE is specified by the Path Computation Element Communication Protocol (PCEP). PCEP allows the PCC (Path Computation Client) to send to the PCE more than one LSP (path computation) request at a time, i.e., multiple LSP requests can be bundled together before being sent to the PCE. Enabling bundling, and consequently the concurrent optimization of a large set of LSP requests at the PCE, may result in significant improvements in terms of network optimization and reduced control plane overhead. However, these advantages come at a cost of increased connection setup-delay. This paper explores pros and cons of enabling bundling of LSP requests in terms of both control plane overhead reduction and benefits of sequential vs. concurrent path computation operations. A variety of scenarios are analyzed, including a WDM mesh network providing LSPs with both dedicated and shared path protection. Results demonstrate significant gains in terms of reduced control overhead using LSP bundling, and reduction in blocking probability using concurrent processing of bundled LSP requests at the PCE.
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| 10. |
- Ahmed, Jawwad, et al.
(författare)
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Bulk provisioning of LSP requests with shared path protection in a PCE-based WDM network
- 2011
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Ingår i: ONDM 2011 - 15th Conference on Optical Network Design and Modeling. - 9783901882425
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Konferensbidrag (refereegranskat)abstract
- The Path Computation Element (PCE) is a network entity utilized for network path computation operations, especially useful in optical networks based on wavelength division multiplexing (WDM). In the PCE paradigm, the communication between a node and the PCE is specified by the Path Computation Element Communication Protocol (PCEP). According to PCEP protocol, multiple LSP (Label Switched Path) requests can be bundled together before being sent to the PCE in order to reduce the control overhead. Multiple bundles received by the PCE can then be provisioned at once as a single bulk. Enabling bulk provisioning of LSP requests at the PCE in a concurrent manner can bring significant improvements in terms of higher network resource utilization and control plane overhead reduction. However, these advantages come at a cost of a longer connection setup-time and of an instantaneous increase in the network load, which may lead to a degradation of the network performance, e.g. blocking probability. In this study pros and cons of bulk provisioning are explored in shared path protection (SPP) by comparing sequential and concurrent path computation strategies. An efficient meta-heuristic named GRASP-SPP-BP (Greedy Random Adoptive Search Procedure for Shared Path Protection with Bulk Provisioning) is proposed for concurrent provisioning of primary and shared backup path pairs. GRASP-SPP-BP minimizes the backup resource consumption while requiring minimal path computation time. The presented results demonstrate that, in a SPP network scenario, a significant reduction in the PCEP control overhead, network blocking probability and backup resource consumption can be achieved via LSP bulk provisioning at the PCE with the proposed GRASP-SPP-BP approach.
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