VANET Traffic Congestion Detection and Avoidance

The main objectives behind the development of congestion detection algorithms are to detect areas of high traffic density with low speeds. Each vehicle captures and disseminates information such as location and speed and process the information received from other vehicles in the network,   which can be possible through VANET. Vehicular Ad-hoc   Networks are self-organizing networks established among   vehicles equipped with communication facilities Due to recent advancements in vehicular technologies vehicular communication has emerged. Multiple approaches have been proposed to implement congestion detection in VANET. Traffic congestion is a very serious problem in big cities. With the number of vehicles increasing rapidly, especially in cities whose economy is booming, the situation is getting even worse. In this paper we are presenting Detection of Traffic Congestion using proposed approach and analysis of result

Anonymous authentication mechanism based on group signature and pseudonym public key infrastructure for safety application of vechicular ad hoc network

Safety applications of Vehicular Ad hoc Network (VANET) demand delay intolerant and are vulnerable to attacks due to the mobility of nodes and wireless nature of their communications. These applications require an integrated security mechanism, which provides message integrity, anonymity, non-repudiation, revocation, availability, and location authentication services. This mechanism should provide acceptable message delay with or without dependency to Road Side Units (RSUs). Realizing the importance of VANET security, two mechanisms are proposed and evaluated in this research. The mechanisms are aimed at fulfilling the VANET security requirements for safety applications with acceptable message delay. Two new lightweight security mechanisms, RSU-Aided Anonymous Authentication (RAAA) and Group Signature-based Anonymous Authentication (GSAA) have been proposed. These mechanisms are based on Group Signature (GS) and Pseudonym Public Key Infrastructure (PPKI). GS scheme was applied to ensure anonymity, non-repudiation and revocation, whereas PPKI was applied to achieve authentication and message integrity. Additionally, a novel function for location verification was proposed to guarantee availability and location authentication. Simulations were performed using NS2 to verify and evaluate the efficiency of the mechanisms for urban and highway scenarios with various traffic conditions. Simulation results showed that RAAA and GSAA outperformed Group Signature and Identity-based Signature (GSIS), and Short-Term Linkable Group Signatures with Categorized Batch Verification (STLGSCBV). In comparison to GSIS and STLGSCBV, the results indicated improvements of at least 5.26% and 7.95% in terms of vehicle density impact on message delay, and at least 11.65% and 11.22% in the case of vehicle density impact on message loss ratio. Furthermore, the simulated RAAA and GSAA methods resulted in approximately 11.09% and 10.71% improvement in message delay during signature verification in comparison to GSIS and STLGSCBV. Additionally, RAAA and GSAA proved to achieve at least 13.44% enhancement by considering signature verification on message loss ratio in comparison to GSIS and 7.59% in comparison to STLGSCBV. The simulation results also demonstrated that less than 20ms message delay was achieved by RAAA and GSAA mechanisms in the case of less than 90 vehicles within the communication range. This is an acceptable message delay and hence, the proposed mechanisms have a great potential to be used in safety critical applications

A New Media Access Control Protocol For VANET: Priority R-ALOHA (PR-ALOHA)

More practical applications of Media Access Control (MAC) protocols arise as the world turns increasingly wireless. Low delay, high throughput and reliable communication are essential requirements for standard performance in safety applications (e.g., lane changes warning, pre-crash warning and electronic brake lights). In particular, multi-priority protocols are important in Vehicular Ad Hoc Networks (VANETs), specifically in Inter-Vehicle Communication (IVC) where safety messages are given higher priority and transmitted faster than normal messages. The R-ALOHA protocol is considered one of the few promising protocols for VANETs because it is simple to implement and suitable for medium access control in Ad Hoc wireless networks. However, R-ALOHA lacks the property of prioritizing the different messages. In this dissertation, a new two-level priority MAC protocol called Priority R-ALOHA (PR-ALOHA) is presented to overcome the lack of priority problem in R-ALOHA. The two levels are low priority and high priority where priority is introduced by reserving specific time slots in the frame exclusively for high priority messages. This effectively increases the number of slots that a high priority message may compete for and thus decreases its delay. A two-dimensional Markov model coupled with Monte Carlo simulation is introduced to investigate the dynamic behavior of PR-ALOHA in steady and transient states. Modeling and simulation results of PR-ALOHA show that PR-ALOHA improves the performance of high priority traffic with limited effect on normal network traffic. Then, a dynamic slot allocation algorithm is introduced to PR-ALOH to optimize slot usage. Finally, a mobility model is introduced to emulate the behavior of the vehicles on the road where the performance of the PR-ALOHA with variable parameters, such as the length of the highway, the vehicle transmission range and the number of vehicles on the road have been investigated. Based on the findings of this dissertation, PR-ALOHA combined with dynamic slot allocation and mobility has a potential in applications like IVC where it can prevent car accidents through faster channel access and rapid transfer of warning messages to surrounding vehicles