Decreasing base units-unequally spaced channel allocation algorithm for dense wavelength division multiplexed transmission systems

Abstract

We propose an unequally spaced channel allocation algorithm, i.e., decreasing base units-unequally spaced (DBU-US) algorithm tested for high-capacity dense wavelength division multiplexed (DWDM) transmission systems. The new scheme decides upon the number of base units (BUs) covering the entire bandwidth and the allocation of different number of channels in the BUs. Starting from BUi = 0, the number of channels in each subsequent BU(BUi = 1 , 2 , 3 ) reduces by a factor of 2, “i” being the index of the BUs. The BUi , BUi + 1 , … have even and odd slot frequency allocations, which creates a substantial degree of unequal channel spacing, which virtually proves to reduce the four wave mixing (FWM) products effectively for any number of transmitted channels. When compared with existing unequal channel allocation schemes of unequally spaced repeated unequally spaced (URUS), alternately paired URUS (APRUS), a reduction of 6.25% and 13.7% in bandwidth is observed, respectively. Similarly, a reduction of FWM products by 45.5%, 41.3%, and 31.7% is observed, when compared with URUS, paired URUS, and APRUS, respectively. The FWM intensities generated by DBU-US are reported to be 5 dBm lesser when compared to widely accepted URUS scheme. Therefore, it is concluded that DBU-US is superior and is considered suitable for DWDM transmission systems.