Inter-relay Handoff in two-hop relaying networks with highly mobile vehicles

In multihop cellular networks, mobile users can communicate with the base stations via relay stations (RSs), and handoff between different RSs. This type of handoffs is referred to as inter-relay handoffs. In networks with highly mobile users, the inter-relay handoffs can occur very frequently. Making intelligent inter-relay handoff decisions is important in order to improve the network performance. In this article, we study the inter-relay handoff decision problem in a two-hop cellular network with highly mobile vehicles using a semi-Markov decision process. The objective is to maximize the total reward, which is defined by taking into consideration the transmission rate of the user's link, the overheads for performing inter-relay handoffs, and the moving speed of the user. Numerical results are shown to demonstrate the effectiveness of the handoff decisions.