An efficient algorithm for placing dispersion-compensating units in wavelength-routed fiber network

Signal distortion due to the accumulated dispersion in relatively long light paths in all optical fiber networks is one of a serious source that limits the network performance. We propose an algorithm for the placement of dispersion-compensating units (DCUs) in transparent wavelength-division multiplexed (WDM) wavelength-routed network. Our algorithm can be used for both non-slope-compensated DCUs (NS-DCUs) and slope-compensated DCUs (SC-DCUs), can ensure the minimum number of DCU required in the network, and can be applied for the case that the number of wavelength is much larger than the number of possible light path. For the employment of the NS-DCUs, we demonstrate that, the bandwidth (or the number of wavelength) that can be used in the network may be restrained by the over (or under) compensation. We assign a part of the optical pan-European network (OPEN) as a sample network. By applying our algorithm, we show that, the number of SC-DCU required for all communication light paths using all wavelengths in the entire C band is 44. On the other hand, 46 NS-DCU are necessary for the same sample network, however; with the limited bandwidth (or the number of wavelength) only a part of C-band.