Title :
Optical tunnel allocation for WDM networks with multi-granularity switching capabilities
Author :
Lee, Steven S W ; Yuang, Maria C. ; Tien, Po-Lung ; Lin, S.H.
Author_Institution :
Dept. of Opt. Commun. Technol., Ind. Technol. Res. Inst., Taiwan
Abstract :
For WDM networks with multi-granularity switching, optical tunnel allocation (OTA) deals with the real-time establishment of optical tunnels between optical nodes through various optical multi-granularity switching devices. OTA is in principle a dynamic routing and wavelength assignment (RWA) problem with multi-granularity switching devices taken into account. In this paper, we propose a novel approximation approach, called Lagrangean relaxation with heuristics (LRH), aimed to resolve RWA considering both fiber and lambda switches. Such RWA is first formulated as a combinatorial optimization problem in which the bottleneck link utilization is to be minimized. To tackle the problem, the LRH approach performs constraint relaxation and derives a lower-bound solution index according to a set of Lagrangean multipliers generated through subgradient-based iterations. In parallel, using the generated Lagrangean multipliers, the LRH approach employs a new heuristic algorithm to arrive at a near-optimal upper-bound solution. Through numerical results and comparisons, we delineate that the LRH approach achieves a near-optimal solution, which is profoundly tight to its lower bound, at the expense of low computational time complexity.
Keywords :
approximation theory; computational complexity; iterative methods; optical fibre networks; optimisation; telecommunication network routing; wavelength division multiplexing; Lagrangean multiplier; Lagrangean relaxation; combinatorial optimization problem; computational time complexity; dynamic routing problem; heuristic algorithm; lower-bound solution index; near-optimal upper-bound solution; optical multigranularity switching device; optical tunnel allocation; wavelength assignment problem; wavelength division multiplexing network; All-optical networks; Heuristic algorithms; Lagrangian functions; Optical devices; Optical fiber devices; Optical fiber networks; Optical switches; WDM networks; Wavelength assignment; Wavelength routing;
Conference_Titel :
Global Telecommunications Conference, 2003. GLOBECOM '03. IEEE
Print_ISBN :
0-7803-7974-8
DOI :
10.1109/GLOCOM.2003.1258732