Improving the efficiency of online upstream scheduling and wavelength assignment in hybrid WDM/TDMA EPON networks

Two general approaches have been followed for solving the problem of upstream grant scheduling and wavelength assignment in hybrid WDM/TDMA EPON networks, i.e. the offline and the online one. The latter boasts significantly lower frame delay performance in all cases. Nevertheless, we show that simplistic online schemes do not utilize wavelength resources as efficiently as possible, especially in the case of large differential distances of ONUs from the OLT. We propose and analyze several low- and higher-complexity solutions to overcome those inefficiencies, leading to improved utilization of network capacity and reduced frame delay. All schemes are evaluated and compared using computer simulations.