JiST: an efficient approach to simulation using virtual machines: Research Articles
Software—Practice & Experience
Wireless Communications & Mobile Computing - Special Issue: Emerging WLAN Apllications and Technologies
Optimal data rate selection for vehicle safety communications
Proceedings of the fifth ACM international workshop on VehiculAr Inter-NETworking
A novel physical carrier sensing scheme for enhancing spatial reuse in multihop wireless networks
WOWMOM '08 Proceedings of the 2008 International Symposium on a World of Wireless, Mobile and Multimedia Networks
Degradation of communication range in VANETs caused by interference 2.0 - real-world experiment
Nets4Cars/Nets4Trains'11 Proceedings of the Third international conference on Communication technologies for vehicles
The scalability problem of vehicular ad hoc networks and how to solve it
IEEE Wireless Communications
A survey on vehicle-to-vehicle propagation channels
IEEE Wireless Communications
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Communication performance in VANETs under high channel load is significantly degraded due to packet collisions and messages drops, also referred to as local channel congestion. So far, research was focused on the control of transmit power and the limitation of the messages rate to mitigate the effects of high load. Few attention has been paid to the carrier sensing setup, i.e controlling WHEN the channel is indicated as clear. In previous work, we identified that the Clear Channel Assessment (CCA) as part of the carrier sensing is a very efficient way of controlling the spatial reuse under high load. The CCA threshold determines at which received power level the channel is sensed busy. In this paper, we propose a stepwise CCA Threshold Adjustment (CTA) depending on how long the packet has been waiting already for medium access. This basic and robust approach mitigates significantly the problem of local message queue drops and hence local congestion. The simulation study confirms the reduction of the average and maximum medium access delay as well as the prevention of message queue drops. Even under inaccurate CCA thresholds among the vehicles, fairness in medium access can be maintained by using CTA. In all cases, the awareness of each vehicle is dramatically improved within the safety-critical area of each vehicle.