John B. Kenney

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Wireless vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication holds great promise for significantly reducing the human and financial costs of vehicle collisions. A common characteristic of this communication is the broadcast of a device's core state information at regular intervals (e.g. a vehicle's speed and location, or a traffic(More)
Emerging applications rely on wireless broadcast to disseminate time-critical information. For example, vehicular networks may exchange vehicle position and velocity information to enable safety applications. The number of nodes in one-hop communication range in such networks can be very large, leading to congestion and undesirable levels of packet(More)
Channel congestion is one of the major challenges for deployment of collision avoidance systems based on DSRC (Dedicated Short Range Communication) in large scale networks. If vehicles do not adapt to congestion conditions, DSRC transmissions could encounter extensive packet losses in areas of high vehicle density, leading to degradation in the performance(More)
IEEE 802.11p is an emerging standard designed to provide wireless access in a vehicular environment. A major application of 802.11p-based Dedicated Short Range Communications (DSRC) is Vehicle to Vehicle (V2V) safety messaging. The US FCC has designated 75 MHz of bandwidth in the 5.9GHz band to support DSRC with a maximum permissible transmit power level of(More)
This paper proposes an approach to Traffic Engineering that uses Differentiated Services (diffserv) and Multi-Protocol Label Switching (MPLS) to provide quantitative QoS guarantees over an IP network. An algorithm that determines QoS-constrained routes is proposed and a framework that uses such an algorithm is outlined. This framework removes the(More)
Many vehicular safety applications rely on vehicles periodically broadcasting their position information and location trace. In very dense networks, such safety messaging can lead to offered traffic loads that saturate the shared wireless medium. One approach to address this problem is to reduce the frequency of location update messages when the movements(More)
The effectiveness of DSRC for collision avoidance depends on the communication performance of safety messages. EDCA, the standard IEEE 802.11 QoS capability, was designed for networks with a mix of voice, video and best effort traffic. This paper examines how to use EDCA to reduce frame collisions for a channel dominated by periodic safety messages. The(More)
Channel congestion is one of the major challenges for IEEE 802.11p-based vehicular networks. Unless controlled, congestion increases with vehicle density, leading to high packet loss and degraded safety application performance. We study two classes of congestion control algorithms, i.e., reactive state-based and linear adaptive. In this paper, the reactive(More)