An Efficient Congestion Control Algorithm for Cam Broadcast over Control Channel in Vehicular Adhoc Networks

Abstract

In this thesis, a novel one-dimensional Vehicle ID based backoff mechanism is introduced newlinefor improving the MAC layer performance of vehicular network. Moreover, to newlineenhance the network performance even at high vehicular density, a vehicle ID based newlineCooperative Awareness Messages (CAM) rate adaptation algorithm is proposed in this newlineresearch work. newlineCAMs are the building blocks for a vehicular network to establish as they provide newlinethe network with the core status information of each of the participating vehicles. In newlineVehicular Adhoc Networks, dissemination of CAMs is the most frequently used message newlinetransmission mode on the Control CHannel (CCH). This makes the CCH being newlineoccupied mostly by CAM messages only. This can eventually lead to ample amount of newlineCAMs on the CCH in case of high vehicular density, thus degrading the performance of newlinevehicular network. A number of research work for MAC layer performance enhancement newlineof vehicular network have been proposed in recent years. Most of these research newlineare based on unicast transmission of CAM, and hence, considers CAM communication newlineto support the provision of acknowledgement. Moreover, most of the existing work newlineassumes the arrival of messages to follow Poisson process, which is practically not newlinefeasible for realistic vehicular environment, as the safety messages are broadcast periodically newlineover the CCH throughout the network. To cope up with these issues, MAC newlineperformance improvement model supporting IEEE 802.11p standard is essential. newline