In practical optical networks, there is often the same number of wavelengths in a fiber. But if it is not carefully designed, there will be much difference in link load among different fibers, and unnecessary waveleng...In practical optical networks, there is often the same number of wavelengths in a fiber. But if it is not carefully designed, there will be much difference in link load among different fibers, and unnecessary wavelengths will be needed. This paper investigated this load balancing issues to minimize the wavelength requirements. Both Integer Linear Programming (ILP) and heuristic algorithms were presented to solve such a problem in WDM optical networks with or without wavelength continuity constraints.展开更多
The problem of routing logical links (lightpaths) on a physical topology of WDM networks in a way that the logical topology remains connected in the event of single physical link failure is called survivable routing. ...The problem of routing logical links (lightpaths) on a physical topology of WDM networks in a way that the logical topology remains connected in the event of single physical link failure is called survivable routing. This paper addresses the survivable routing problem with and without wavelength-continuity constraints by proposing a new Integer Linear Programming (ILP) algorithm, which is based on a simplified necessary and sufficient condition. Numerical results are given and discussed to show that survivable routing solutions of most logical topologies can be found by the algorithm of the authors. Furthermore, comparing with other similar methods, the above algorithm can find out a survivable solution in much shorter time, and it works especially well with sparse-connected logical topologies. The impact of wavelength-continuity constraints and the other factors that influence the probability to find out a survivable solution are also discussed in the paper.展开更多
文摘In practical optical networks, there is often the same number of wavelengths in a fiber. But if it is not carefully designed, there will be much difference in link load among different fibers, and unnecessary wavelengths will be needed. This paper investigated this load balancing issues to minimize the wavelength requirements. Both Integer Linear Programming (ILP) and heuristic algorithms were presented to solve such a problem in WDM optical networks with or without wavelength continuity constraints.
文摘The problem of routing logical links (lightpaths) on a physical topology of WDM networks in a way that the logical topology remains connected in the event of single physical link failure is called survivable routing. This paper addresses the survivable routing problem with and without wavelength-continuity constraints by proposing a new Integer Linear Programming (ILP) algorithm, which is based on a simplified necessary and sufficient condition. Numerical results are given and discussed to show that survivable routing solutions of most logical topologies can be found by the algorithm of the authors. Furthermore, comparing with other similar methods, the above algorithm can find out a survivable solution in much shorter time, and it works especially well with sparse-connected logical topologies. The impact of wavelength-continuity constraints and the other factors that influence the probability to find out a survivable solution are also discussed in the paper.
