Cross-layer Mobile Chord P2P protocol design for VANET

Various ongoing research efforts in Vehicular Ad hoc Network (VANET) related to safety and non-safety applications have been published in academia and industry. One of the main areas in VANET that is still lacking of significant research contributions is toward designing reliable Medium Access Control (MAC) protocols. Existing surveys on MAC protocols in VANET mostly discuss general MAC methods, that include contention-based and contention-free MAC protocols. A hybrid MAC protocol that adopts both contention-based and contention-free MAC, proposed to enhance the network performance in VANET, is fruitful to be explored further. Hence, a survey of hybrid MAC protocols for VANET is presented in this paper. The benefits and limitations of the existing hybrid MAC protocols are discussed based on their classification to provide some insights into the recent advancement of high-performance MAC protocols for vehicular networks. Finally, some open research issues are highlighted as part of future research directions that need further investigations.

The popular content distribution (PCD) problem in Vehicular Ad-hoc Networks (VANETs) is considered. We model this problem as a coalitional graph game in which the on-board units (OBUs) try to form a peer-to-peer (P2P) network where one OBU transmits files to multi OBUs but receives from only one OBU each time, to complete the data dissemination efficiently. In this game, the OBUs engage in bilateral negotiations which result in a bilaterally agreement of forming a directed link among OBUs. Once the network is constructed, the OBUs will transmit the content pieces to each other. We study this game under a form of myopic dynamics which is carried out by each OBU in a distributed way. Furthermore, the network formed in this game is a pairwise stable network. Simulation results show that the proposed approach performs better comparing with the non-cooperative case.

The Local Rarest Bundle First (LRBF) and Local Rarest Generation First (LRGF), content distribution strategies for delayed-tolerance networks (DTNs), reach high delivery rate in the vehicular ad-hoc networks (VANETs), where intermittent connectivity due to permanent network fragmentation and node mobility are main challenges. However, in order to achieve a high delivery rate, both strategies require each node to periodically transmit control packets with information about the availability of its resources to its neighbors. This large amount of control packets causes overhead on the network. To overcome this effect, we are proposing a content distribution strategy based on a Bloom Filter. The results showed that our strategy significantly reduced the size of control packets decreasing the network overhead. Besides that, the number of nodes that obtains the least disseminated packets is much smaller.

The boost of wireless technology brings dramatic growth for Vehicular ad-hoc networks(VANETs). The effective routing and forwarding protocol is critical for the performance of VANETs thus influence the automatic driving and information distribution. The dynamic characteristic of vehicle to vehicle(V2V) communications makes it hard to maintain a reliable path between vehicles. In order to improve transmission performance in VANETs, we make full use of the Content-centric information dissemination, and there are some existing efforts on proving feasibility of content-centric network(CCN). In this paper, we propose a novel Source Selection Dynamically Network Coding-based Information Centric Network protocol (SSDNC), which introduces CCN architecture in VANET. SSDNC exploit the features of CCN to make multiple sources exist. With the application of Analytic Hierarchy Process(AHP), requested symbols can be distributed adaptively to different interfaces according to their weight. Then the forwarding decisions will be made to obtain the information that makes transmission more effective. Moreover, we take advantage of network coding (NC) to eliminate the network redundancy for the purpose of achieving higher performance. We evaluate the performance of the SSDNC using ndnSIM over NS-3 network simulator, which focused on the size of chunk, throughput and average transmission delay and compared with ICTP [1]. The result shows that the performance of our protocol is better than ICTP.

Location tracking of mobile entity becomes a research challenge for applications in vehicular networks, mobile sensor networks and mobile adhoc networks. The GPS based tracking in vehicular networks has limitations in certain scenarios such as inside tunnels, tall buildings, dense forests, etc. Tracking of fast-paced mobile entity (say mobile node) finds applications in vehicular networks such as chasing, hit-and-run accidents, etc. Connected dominating set(CDS) provides a virtual backbone in adhoc network. This paper uses connected dominating set(CDS) based virtual backbone in vehicular adhoc networks for tracking of fast-paced mobile node's location. We show that using a simple heuristics that the location updates for mobile node can be reduced to the tune of 40%.

The Vehicular Ad Hoc Networks (VANETs) paradigm is a promising technology to enable the Internet of Vehicles (IoV) for future integration with 5G and 6G infrastructures in smart cities. However, VANET can be susceptible to wireless interference, like co-channel interference, which can cause communication quality and performance to deteriorate, threatening vehicular safety applications, including traffic management and accident prevention. Hence, VANET requires practical interference mitigation strategies, such as digital beamforming, that mitigate the signals from unwanted directions while improving the reception of signals from desired directions with adequate precision, which is helpful for VANET’s highly mobile environments. In this paper, a review of the literature on digital beamforming techniques is carried out that examines their advantages and limitations. Furthermore, an important contribution of this paper is the development of an experimental platform for a roundabout VANET based on simulations, where different digital beamforming algorithms, such as phase-shift and Minimum-Variance Distortionless-Response (MVDR), are tested. The results show that the MVDR algorithm leads to improvement due to its adaptability to ad hoc environments. Also, they show thatMVDRadaptive beamforming improves Signal-to-Interference-plus-Noise Ratio (SINR) and reduces outage event proportion compared to non-beamforming and conventional beamforming scenarios, highlighting their potential to mitigate co-channel interference in highly changing VANET environments. Therefore, adaptive digital beamforming can improve the performance and reliability of VANETs, offering the potential for advanced wireless network implementations in smart cities with 5G and 6G infrastructures.

In intelligent transportation systems, the collaboration between vehicles and the road side units is essential to bring these systems to realization. The emerging Vehicular Ad Hoc Network (VANET) is becoming more and more important as it provides intelligent transportation application, comfort, safety, entertainment for people in vehicles. In order to provide stable routes and to get good performance in VANET, there is a need of proper routing protocols must be designed. In this paper, we are working with the very well-known ad-hoc on-demand distance vector (AODV) routing protocol. The existing Routing protocol AODV-L which is based on the Link expiration time is extended to propose a more reliable AODV-AD which is based on multichannel MAC protocol. For the performance evaluation of routing protocols, a simulation tool ‘NS2’ has been used. Simulation results show that the proposed AODV-AD protocol can achieves better performances in forms of high Route stability, Packet Delivery ratio and packet loss rate than traditional AODV-L and traditional AODV.

Given the resource consumption of transmitting data packets in Vehicular Ad Hoc Network (VANET), selfish nodes might refuse to transmit messages to others just for maximizing their own profits. Therefore, the communication performance within the whole network would be affected. Along with its wide-scale implementation in many road-side applications, selfish behaviors of such nodes are witnessed to be causing serious problems and degradations in VANETs. We address the impacts of the selfish nodes in the performance of VANETs and accordingly, the credit-based method is utilized to re-implement the spirit that can provide incentive for mobile nodes to cooperate with each other and report actions honestly. The simulation results demonstrated that the system earnings would decrease due to the existence of selfish nodes, thereby also proving that the incentive mechanism can facilitate mutual cooperation among nodes.

Vehicular communications enable a variety of applications to improve road safety, driving experience, and traffic management. Many of these applications require data to be routed through multiple hops until they reach to the destination. Unfortunately, due to highly dynamic driving patterns of vehicles, it is challenging to achieve effective and time-sensitive data forwarding in vehicular ad hoc networks (VANETs). Both social- based and trajectory-assisted data forwarding strategies have been proposed to improve packet delivery performance in VANETs. The former reaches limited data delivery ratio and the latter leaks location privacy of drivers. In this paper, we propose a privacy-preserving data forwarding protocol based on personal-social behaviors of drivers to achieve highly reliable transmissions and privacy preservation for drivers in VANETs. Specifically, by observing the phenomenon that vehicles regularly visit some social spots, such as shopping malls, museums and busy intersections, we can obtain the personal-social behaviors of drivers. Based on these behaviors, the messages can be delivered to roadside units (RSUs) at the social spots frequently visited by vehicles. Later, once a vehicle visits the social spots, it can successfully retrieve the messages destined for it from the RSUs anonymously. In addition, the identities of senders are conditionally preserved and the personal-social behaviors of drivers are protected against a global adversary. Performance evaluation demonstrates its efficiency in terms of high delivery ratio and low average delay.

Software-defined vehicular network (SDVN): A survey on architecture and routing

Vehicular adhoc networks (VANETs) are made by applying the standards of mobile adhoc networks (MANETs)-the unconstrained making of a remote network of cell phones to the area of vehicles. VANETs were first referenced and presented in 2001 under ”vehicle to-vehicle specially appointed versatile correspondence and systems administration” applications, where networks can be shaped and data can be handed-off among vehicles. It was shown that vehicle-to- vehicle and vehicle-to-road side exchange designs will exist together in VANETs to give street security, route, and other side of the road administrations. VANETs are a vital piece of the intelligent transportation frameworks (ITS) system. At times, VANETs are known as Intelligent Transport Networks. They are perceived as having advanced into a more extensive “Web of vehicles”. Which itself is relied upon to eventually advance into a “Web of self-sufficient vehicles”. The vehicles send some data about street status and traffic. But sometimes the information send from one vehicle to another can be malicious. This malicious information is added by the intruders to cause problem in vehicular network so that accident can occur. In this report, we will analyse the throughput, packet delivery ratio and end to end delay in sending information from vehicle to vehicle when the network is attacked by some malicious nodes.

Vehicular Ad-hoc Networks (VANET) are considered a promising application in Intelligent Transport Systems (ITS). It is characterized by a high mobility, a high density of nodes, and a very constrained topology that require a more suitable and more reliable routing protocol. Hence, the need to optimize the current routing protocols used in Mobile Ad-hoc Networks (MANET), in order to increase their performance in VANET. Broadcast communication method remains a very important step to adapt the broadcast information to other nodes and to select the routes in better conditions. In this article, we propose a new broadcast approach based on the neighborhood broadcasting methods. Based on this solution, we present an improving Ad-hoc On-Demand Distance Vector Routing (AODV) to reduce the number of dropped packets, and minimize network overhead. The simulation shows encouraging results of our proposed approach.

Vehicular Ad hoc Network (VANET) has been gaining the attention from the academic and industry communities due to the promising applications in road safety, traffic management and passenger comfort. However, the short vehicle-to-vehicle (V2V) communication range and the nature of vehicle mobility impose many challenges in packet routing and, accordingly, infrastructure-based applications, e.g., Internet access. For more reliable communication, automobile manufacturers have started the investigation to deploy cellular networks, such as LTE, to support in-car Internet access. In addition to the high communication cost to the end-user, using centric cellular networks for vehicular communication applications causes data explosion and network overload. A feasible solution is using VANETs for mobile data offloading when connectivity to infrastructure is guaranteed, which requires an efficient routing protocol with global connectivity awareness. In this paper, we propose a novel infrastructure-based, dynamic, and connectivity-aware routing protocol, iCARII, to enable infotainment applications and Internet access in an urban environment. iCARII aims to improve VANETs routing performance by enabling selecting roads with guaranteed connectivity and reduced delivery delay. Detailed analysis and simulation-based evaluations of iCARII demonstrate the significant improvement of VANET performance in terms of packet delivery ratio and end-to-end delay with a negligible cost of routing overhead.

Most applications in urban vehicular ad hoc networks (VANETs) rely on information sharing, such as real‐time traffic information queries, and advertisements. However, existing data dissemination techniques cannot guarantee satisfactory performance when amounts of information requests come from all around the network. Because these pieces of information are useful for multiple users located in various positions, it is beneficial to spread the cached copies around. Existing work proposed caching mechanisms and conducted simulations for validation, but there is a lack of theoretical analysis on the explicit caching effects. Because of the complex urban environment and high mobility of vehicles, quantifying the caching effects on the VANET performance is quite challenging. We present the cache coverage ratio as the metric to measure the caching effects, and theoretical analysis is given based on reasonable assumptions for urban VANETs, through which we find the affecting factors include vehicle density, transmission range, and ratio of caching vehicles. We deduce the quantitative relationship among them, which have similar forms as the cumulative density function of an exponential distribution. We also consider the impact of vehicle mobility to predict the future cache effect on surrounding roads of the caching area. We conduct intensive simulations, which verify that the theoretical analysis results match quite well with the simulated reality under different scenarios. Copyright © 2015 John Wiley & Sons, Ltd.

EAPRAD: A MAC protocol for Enhancing Access Probability and Reducing Access Delay in VANETs