End⁃to⁃End Rate Adaptation to Support Heterogeneous Services for Infrastructure⁃Based Vehicular Networks

[Abstract] Vehicle to Infrastructure (V2I) communications aim to provide mobile users on the road low⁃cost Internet and driver safety services. However, to meet Quality of Service (QoS) requirements of various applications and efficiently utilize limited wireless channel resources, the transport layer protocol has to perform effective rate control in low channel quality and frequent changing topology communication environment. In this paper, we propose a novel rate⁃control scheme in infrastructure based vehicular networks that avoids congestion and starvation and promotes fairness in end⁃to⁃end V2I communications. In vehicular networks, a bottleneck roadside unit (RSU) keeps track of its buffer size, aggregate incoming rate, and link throughput, and appropriately allocates bandwidth to traversing flows. With feedback information from the RSU, source nodes dynamically adjust their sending rates to avoid buffer overflow or starvation at the bottleneck RSU. Simulation results show that the proposed scheme can reduce not only packet losses owing to buffer overflow but also buffer starvation time, which improves the utilization efficiency of wireless channel resource.

[Keywords] vehicle to infrastructure communications; roadside unit; congestion avoidance; starvation avoidance; transport layer