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.
Original language | English |
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Pages | 2730-2734 |
Number of pages | 5 |
DOIs | |
State | Published - 2003 |
Event | IEEE Global Telecommunications Conference GLOBECOM'03 - San Francisco, CA, United States Duration: 1 Dec 2003 → 5 Dec 2003 |
Conference
Conference | IEEE Global Telecommunications Conference GLOBECOM'03 |
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Country/Territory | United States |
City | San Francisco, CA |
Period | 1/12/03 → 5/12/03 |
Keywords
- Combinatorial optimization problem
- Lagrangean relaxation
- Multi-granularity switching capabilities
- Optical tunnel allocation
- Routing and Wavelength Assignment (RWA)
- Subgradient method
- Wavelength Division Multiplexing (WDM)