Section: New Results

Study on the IEEE 802.11p Channel Congestion Problem

Participant : Oyunchimeg Shagdar.

The IEEE 802.11p is a standardized WiFi technology dedicated to V2X communications for especially road safety and efficiency applications. It is expected that vehicles periodically broadcast messages to announce their existences using the IEEE 802.11p frequency channel. However, because the IEEE 802.11p has a limited wireless bandwidth, in dense traffic conditions the V2V communications performances are poor, failing to satisfy the application requirements. In RITS, we study the issue and develop congestion control algorithms. In 2014, we studied the reactive distributed congestion control algorithm, proposed by the European Telecommunications Standards Institute (ETSI), and showed that the algorithm creates unstable resource utilization, which can cause the reactive Distributed Congestion Control (DCC) to perform worse than non-DCC systems. We proposed an asynchronous algorithm, where DCC control is made in such a way that channel resource is used in an asynchronous manner by the different stations. Our results show that the asynchronous DCC approach outperforms both the non-DCC and reactive DCC mechanisms. The work has been reported at a ETSI meeting in December 18, 2014 [54] .