Supporting real-time traffic in multihop vehicle-to-infrastructure networks

In this paper, a new Controlled Vehicular Internet Access protocol with QoS support (CVIA-QoS) is introduced. CVIA-QoS employs fixed gateways along the road which perform periodic admission control and scheduling decisions for the packet traffic in their service area. The CVIA-QoS protocol is based on Controlled Vehicular Internet Access (CVIA) protocol that was designed only for the best-effort traffic. The most important contribution of the CVIA-QoS protocol is providing delay bounded throughput guarantees for soft real-time traffic, which is an important challenge especially for a mobile multihop network. After the demands of the soft real-time traffic is met, CVIA-QoS supports the best-effort traffic with the remaining bandwidth. Simulation results confirm that in CVIA-QoS protocol, the real-time throughput is not affected from the best-effort load and its delay is much smaller than CVIA delay when both the real-time and best-effort load exist in the channel. It has been observed that, unlike, CVIA-QoS, IEEE 802.11e with multi-hopping suffers from lower throughput and high number of real-time packet drops.