OPTIMIZING AMPLIFIER PLACEMENTS IN A MULTIWAVELENGTH OPTICAL LAN MAN - THE EQUALLY POWERED WAVELENGTHS CASE/

Wavelength division multiplexing (WDM) provides the ability to utilize the enormous bandwidth offered by optical networks, using today's ele ctronics. WDM-based optical networks employing passive-star couplers h ave been proposed for deployment in local and metropolitan areas. Opti cal amplification is often required in such networks to compensate for the signal attenuation along the fiber links and the splitting and co upling losses in the network. However, an optical amplifier has constr aints on the maximum gain and the maximum output power it can supply; thus optical amplifier placement becomes a challenging problem. A simp lifying assumption for analytical tractability requires that all wavel engths, present at a particular point in a fiber, be at the same power level, viz, the equally powered-wavelengths case. However, previous s tudies did not minimize the total number of amplifiers while achieving power equalization. In this paper, me formulate the minimization of a mplifiers with power equalization as a mixed integer linear program (M ILP) that can be solved by a linear program solver. illustrative examp les on sample networks are presented, which demonstrate the characteri stics and the advantages of our optimal amplifier placement algorithm.