An unified QoS-aware rate control scheme in vehicular WiFi networks

Through wireless Vehicle to Infrastructure (V2I) communications, mobile users are able to obtain a number of Internet services such as web browsing, video streaming, file downloading, online gaming, etc., or safety related services such as road accident alerting, traffic jam broadcast, and so on, which makes their traveling more comfortable and safe. In order to meet diverse Quality of Service (QoS) requirements of various multimedia applications and efficiently utilize the limited wireless channel resource, the transport layer protocol has to conduct effective end to end rate control in low channel quality and frequent changing topology communication environment. In this paper, we propose an novel rate control scheme in WIFI based vehicular networks, and target to address some challenging issues such as congestion avoidance, starvation avoidance, fairness, etc., for end to end data communications. In order to achieve the aforementioned research goals, a bottleneck roadside unit timely keeps track of the buffer size, aggregated incoming rate, and link throughput, and dynamically makes appropriate rate feedbacks to source nodes to avoid buffer overflow or starvation. Simulation results show that the proposed scheme can not only decrease packet losses owing to buffer overflow but also reduce buffer starvation time, which improves the utilization efficiency of wireless channel resource.