Mobile relay in LTE-advanced systems

Voice and data communications on high speed vehicles encounter bad channel condition, high call drop rate, serious signaling congestion and excessive power consumption of UE. Mobile relay technology which features on-board relay node is expected to improve the quality of service for passengers. However, the design for fixed relay in LTE-Advanced system cannot meet the requirements of mobile relay. In this article, the architecture for mobile relay is presented. The key techniques of supporting mobile relay are investigated, such as the group mobility, the local service support, the multi-RAT and RAN sharing, with the corresponding solutions. The potential system optimization, for example, the self-optimization network, power saving, measurement and system information acquisition are also presented where the efficiency of mobile relay can further be improved. Simulation and numerical results demonstrate the feasibility of the mobile relay.