Efficient ONU Migration for Fixed and Mobile Convergence Network in High-Speed Rail Area

Large number of high-speed mobile users in high-speed rail (HSR) and surrounding areas produce bandwidth requirements with space-time uneven distribution characteristics, which leads to the congestion and waste of bandwidth resource in wireless bearer network. And under the huge bandwidth demands of future 5G network, the congestion and low efficiency will be more severe. To meet bandwidth requirements, bearer network bandwidth capacity is provided according to the highest bandwidth demands. This results in the low utilization efficiency and an increase of access network costs. In order to solve the low bandwidth utilization problem while keeping the deployment costs at a low level, we propose a flexible fixed mobile convergence (FMC) access network architecture in which the clustered time wavelength division multiplexing passive optical networking (TWDM-PON) is introduced as a fronthaul and fixed network access bearer technology. In this architecture, optical network units (ONUs) are capable to be migrated flexibly between different optical line terminals (OLTs) to improve the bandwidth utilization of idle OLTs. Meanwhile, while taking into account the impactor of network quality - ONU switching times and transmission distance, a flexible ONU migration algorithm (OMA) is proposed to maximize bandwidth resource utilization. The simulation results show that the OMA promote the overall bandwidth resources utilization of OLTs.