Number Of Safety Messages Research Articles

Cooperative Message Authentication in Vehicular Cyber-Physical Systems

The vehicular ad hoc network presents a very complex cyber-physical system with intricate interplay between the physical and cyber domains. In the physical domain, vehicles need to frequently broadcast their geographic information. The safety message broadcasting in an area with a high density of vehicles tends to incur a large data traffic rate that should be properly processed in the cyber domain. In this paper, we address the issue of large computation overhead caused by the safety message authentication. Especially, a cooperative message authentication protocol (CMAP) is developed to alleviate vehicles' computation burden. With CMAP, all the vehicles share their verification results with each other in a cooperative way, so that the number of safety messages that each vehicle needs to verify reduces significantly. Furthermore, we study the verifier selection algorithms for a high detection rate of invalid messages in a practical 2-D road scenario. Another important contribution in this paper is that we develop an analytical model for CMAP and the existing probabilistic verification protocol , considering the hidden terminal impact. Simulation results over a practical map are presented to demonstrate the performance of the proposed CMAP with comparison to the existing method.

Congestion Control Framework for Disseminating Safety Messages in Vehicular Ad-Hoc Networks (VANETs)

The purpose of this study is to propose a new congestion control framework for uni-priority of event-driven safety messages in VANETs. The uni-priority congestion is caused by the traffic of the same priority. Many of event-driven safety applications developed for VANETs is required real-time communication with high reliability and must be delivered before certain time deadline. In high load traffic, the CCH communication channel easily congested. Many studies [2,10,11,12] recommended congestion control approach to control the load and congestion on the wireless channel in VANETs. Our proposed congestion control will reserve the CCH communication channel for event-driven safety messages if the number of safety messages in the queue exceeds a defined threshold or the congestion control detect event-driven safety message. In normal traffic, the CCH communication channel is not reserve for event-driven safety messages. This research will adapt priority-based Earliest Deadline First (EDF) scheduling algorithms in proposed congestion control to schedule uni-priority of eventdriven safety messages. In addition, to provide reliability performance for event-driven safety messages, we will develop a new rebroadcasting scheme to prevent broadcast storm. In next phase of study, we plan to test and evaluate performance of our congestion control approach using network simulator e.g. NS-3.