A novel handover scheme for seamless wireless connectivity in high-speed rail

It is a great challenge to design an efficient handover scheme of broadband wireless communication systems for high-speed rail to reduce the communication interruption time during handover. A seamless handover scheme based on the dual-layer and dual-link system architecture is proposed in this paper. In the scheme, two antennas are mounted at the front and rear of a train, and one of them executes handover while the other is still communicating with BS. Therefore, the communication will not be interrupted throughout the handover. Furthermore, bi-casting is adopted to eliminate the data forwarding delay between the serving BS and target BS. In order to reduce handover implementation overhead, a Train Relay Station is employed to represent all the users in a train to execute handover in the proposed scheme. The performance of the proposed scheme is analyzed in terms of handover probability, handover failure probability and communication interruption probability. Simulation and theoretical results show that the proposed scheme can efficiently support seamless handover for high-speed trains with low implementation overhead.