Adaptive coded-modulation for the next-generation intelligent optical transport networks

We review adaptive modulation in optical communications and present a pragmatic implementation to simplify the transponder complexity. We reveal that when adaptive modulation is employed in the DWDM optical transmission system channel launch powers should be rearranged to optimize the whole system. In addition, we introduce adaptive trellis-coded modulation scheme as an extension of adaptive modulation and the combination of both can provide sufficient transmission flexibility, which is highly desired for the next-generation intelligent optical transport networks.