Dual-Backhaul Links in LTE - A Mobile Relay System for High-Speed Railways

Serving hundreds of User Equipments onboard of a high-speed train is a very big challenge in terms of resources and mobility management. In addition to the high penetration loss, direct connection between the Evolved Node B and fast User Equipment leads to increased handoff failure rate, and increased power consumption of Vehicular User Equipments. Moreover, sufficient bandwidth may not be gotten from only one Macro Evolved Node B to cover the required throughput of the large-number of diverse-operators User Equipments. Mobile Relay mechanism has been introduced in Release 12 of LTE-Advanced system to be one of the most significant solutions to solve some of these issues. Usually, Mobile Relays are installed on the roof of the train and act as small nodes. In our work, we are considering using the Carrier Aggregation scheme to provide the sufficient bandwidth through a dual-backhaul connection with two Macro base stations. The proposed work makes the group Handoff more seamless as well as improves the user throughput. Simulation results show better performance in terms of system throughput, blocking probability, and packet loss.