Balancing the Impact of ONU Tuning Overhead in Reconfigurable TWDM-PONs: An FPGA-Based Evaluation

In TWDM-PON, the utilization of tunable transceivers at the ONUs allows to dynamically reconfigure the OSU-ONU pairings to decrease, for example, the energy consumption at the OLT. However, if the utilized dynamic wavelength and bandwidth allocation (DWBA) does not take into account which ONUs are reallocated, the ONU tuning overhead can severely impact the average frame delay experienced by the tuning ONUs. The paper shows that, by alternating the ONUs that tune at each reconfiguration, the impact of ONU tuning overhead on average frame delay is fairly distributed among the ONUs.