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Full-Text Articles in Engineering
Establishing Physical Survivability Of Large Networks Using Properties Of Two-Connected Graphs, Daryoush Habibi, Hoang N. Nguyen, Quoc Viet Phung, Kung-Meng Lo
Establishing Physical Survivability Of Large Networks Using Properties Of Two-Connected Graphs, Daryoush Habibi, Hoang N. Nguyen, Quoc Viet Phung, Kung-Meng Lo
Research outputs pre 2011
Establishing the physical survivability of large networks is not a trivial task. Some techniques for assessing physical survivability such as the cutset method can not deal with large size networks (S. Ramamurthy and B. Mukherjee), (W.N. Grover and J. Doucette, 2001). A fast technique for finding biconnected components of a graph and testing the network for node-/link-bridges, presented in (W.D. Grover, 2004), does not provide any further information, such as identifying the fundamental cycles within the network, which would significantly benefit the next phase of network design for protection using such techniques as shared backup path protection (SBPP), p-cycle, or …
K Pair Of Disjoint Paths Algorithm For Protection In Wdm Optical Networks, Quoc Viet Phung, Daryoush Habibi, Hoang N. Nguyen, Kungmang Lo
K Pair Of Disjoint Paths Algorithm For Protection In Wdm Optical Networks, Quoc Viet Phung, Daryoush Habibi, Hoang N. Nguyen, Kungmang Lo
Research outputs pre 2011
Survivable routing in wavelength division multiplexing (WDM) optical networks has been proven to be NP-hard problem. There is a trade-off between the computational time and the optimality of solutions in existing approaches to the problem. Existing heuristic approaches purely based the graph algorithms are efficient in computational time but do not offer optimal solutions and may fail in some cases even when a solution exists. Meanwhile, the integer linear programming (ILP) models offer optimal solutions but are intractable even with moderate scale networks. In this paper, we introduce a new algorithm for finding K pairs of disjoint paths which are …
Dynamic Wavelength Routing In All Optical Mesh Network, Kungmang Lo, Daryoush Habibi, Quoc Viet Phung, Hoang Nghia Nguyen
Dynamic Wavelength Routing In All Optical Mesh Network, Kungmang Lo, Daryoush Habibi, Quoc Viet Phung, Hoang Nghia Nguyen
Research outputs pre 2011
Wavelength-division multiplexing (WDM) offers the capability to handle the increasing demand of network traffic in a manner that takes advantage of already deployed optical fibers. Lightpaths are optical connections carried end-to-end over a wavelength on each intermediate link. Wavelengths are the main resource in WDM networks. Due to the inherent channel constraints, a dynamic control mechanism is required to efficiently utilize the resource to maximize lightpath connections. In this paper, we investigate a class of adaptive routing called dynamic wavelength routing (DWR), in which wavelength converters (WCs) are not utilized in the network. The objective is to maximize the wavelength …
A Shared Backup Path Protection Scheme For Optical Mesh Networks, Hoang N. Nguyen, Daryoush Habibi, Quoc Viet Phung, Kungmang Lo
A Shared Backup Path Protection Scheme For Optical Mesh Networks, Hoang N. Nguyen, Daryoush Habibi, Quoc Viet Phung, Kungmang Lo
Research outputs pre 2011
We propose a new heuristic ILP model for share backup path protection (SBPP) scheme of mesh networks, which used the sets of disjoint-joint primary-backup path candidates of using path-pair candidates. The solution of the model is near optimal and provides all the routing details of demands as well as the sharing information between backup paths, and also simplifies the wavelength assignment problem if the wavelength continuity is a consideration. The new entities are introduced into this model that allow to control the resource utilization as well as congestion level of the network for optimization purposes and the pre-processing of data …
Dynamic P-Cycles Selection In Optical Wdm Mesh Networks, Kungmang Lo, Daryoush Habibi, Quoc Viet Phung, Hoang Nguyen, Byungkyu Kang
Dynamic P-Cycles Selection In Optical Wdm Mesh Networks, Kungmang Lo, Daryoush Habibi, Quoc Viet Phung, Hoang Nguyen, Byungkyu Kang
Research outputs pre 2011
P-cycles have been recognized as a useful protection scheme in WDM mesh networks. This is a type of shared link protection that not only retains the mesh-like capacity efficiency, but also achieves the ring-like protection switching speed. However, finding the optimal set of p-cycles for protecting traffic demands is not a simple task and is an NP-hard problem. A general approach is to determine a set of candidate p-cycles and then determine optimal or near-optimal solutions by using integer linear programming (ILP) models or heuristics. In a dense mesh network, however, the number of candidate cycles is huge, and increases …
Capacity Utilization Versus Congestion Levels In Wavelength Routing For Large Scale Wdm Networks, Quoc Viet Phung, Daryoush Habibi, Hoang N. Nguyen, Kungmang Lo
Capacity Utilization Versus Congestion Levels In Wavelength Routing For Large Scale Wdm Networks, Quoc Viet Phung, Daryoush Habibi, Hoang N. Nguyen, Kungmang Lo
Research outputs pre 2011
Wavelength routing (WR) has been a key issue in WDM optical networks which carry huge amount of traffic aggregated from Internet protocol (IP), asynchronous transfer mode (ATM) and SDH/SONET layers. The problem, however, has been proved NP-hard. The time complexity and the optimality of solutions are two conflicting metrics. In addition, for optimization purposes, capacity utilization and network congestion level can be compromised to reduce the blocking probability of future connections. In this paper, we propose a heuristic approach for WR in large scale networks based on a balanced model developed for the capacity utilization and the congestion level. This …