Explicit rate based transmission control scheme in vehicle-to-infrastructure communication networks

In Vehicle-to-Infrastructure (V2I) communication networks, mobile users are able to access Internet services, such as video streaming, digital map downloading, database access, online gaming, and even safety services like accident alarm, traffic condition broadcast, etc., through fixed roadside units. However, the dynamics of communication environment and frequent changing topology critically challenge the design of an efficient transport layer protocol, which makes it difficult to guarantee diverse Quality of Service (QoS) requirements for various applications. In this paper, we present a novel transport layer scheme in infrastructure based vehicular networks, and aim to resolve some challenging issues such as source transfer rate adjustment, congestion avoidance, and fairness. By precisely detecting packet losses and identifying various causes of these losses (for example, link disconnection, channel error, packet collision, buffer overflow), the proposed scheme adopts different reacting mechanisms to deal with each of the losses. Moreover, it timely monitors the buffer size of the bottleneck Road-Side Unit (RSU), and dynamically makes transfer rate feedbacks to source nodes to avoid buffer overflow or vacancy. Finally, analysis and simulation results show that the proposed scheme not only successfully reduces packet losses because of buffer overflow and link disconnection but also improves the utilization efficiency of channel resource.