“…Generally, data transmission between different optical network variants will be via optical nodes, connecting for instance, backbone optical networks (BONs) to metro access networks (MANs) or local access networks (LANs). These optical networks usually differ in their data traffic types, network dimensions, access terminals and so on, with corresponding optimal modulation formats for each [7], [8]. Advanced modulation formats including m-ary quadrature amplitude modulation (mQAM) and m-ary phase shift keying (mPSK) have higher spectrum efficiency (SE) and better chromatic dispersion (CD) tolerance.…”