Opportunistic Vehicular Communication: Challenges and Solutions

Vehicular ad-hoc network (VANET) technology enables communication between vehicles, or vehicles and road-side units (RSUs) through wireless communication devices installed on the vehicles. One of the most important goals of VANETs is providing safety applications for passengers. In addition, VANETs provide comfort applications to users. Guaranteeing a reliable and stable routing protocol over VANETs is a very important step. The proposed research attempts to improve routing protocols that decrease the end-to-end delay to suit VANET communication characteristics. In addition, it proposes analysis of the end-to-end delay probability distribution. More specifically, we derive a closed-form expression for the probability distribution of the re-healing delay in a VANET conditioned on the distance between two VANET clusters. Furthermore, we propose a closed-form expression for the probability distribution of the unconditional re-healing delay. Moreover, we develop a mathematical model to calculate the probability distribution of the end-to-end delay. On the other hand, using Unmanned Aerial Vehicles (UAVs) or drones in wireless communications and Vehicular Ad-hoc Networks (VANETs) has started to attract attention. We propose a routing protocol that uses infrastructure drones for boosting VANET communications to achieve a minimum vehicle-to-drone packet delivery delay. In addition, we propose a closed-form expression for the probability distribution of the vehicle-to-drone packet delivery delay on a two-way highway. Moreover, based on that closed-form expression, we can calculate the minimum drone density (maximum separation distance between two adjacent drones) that stochastically limits the worst case of the vehicle-to-drone packet delivery delay. Furthermore, we propose a drones-active service (DAS) that is added to the location service in a VANET. This service dynamically and periodically obtains the required number of active drones based on the current highway connectivity state by obtaining the maximum distance between each two adjacent drones while satisfying a probabilistic constraint for vehicle-todrone packet delivery delay. Our analysis focuses on two-way highway VANET networks with low vehicular density. The simulation results show the accuracy of our analysis and reflect the relation between the drone density, vehicular density and speed, other VANET parameters, and the vehicle-to-drone packet delivery delay. In addition, we propose a new routing protocol called multi-copy intersection-based routing (MCIR) for vehicular ad-hoc networks (VANETs) in urban areas. MCIR is an intersectionbased routing protocol that forwards multiple copies of the packets in different road segments. Moreover, it is a beacon-less routing protocol with a carry-and-forward strategy. We show via simulation that the MCIR protocol is superior to other existing routing protocols, especially in low vehicular density scenarios. The results show that MCIR achieves a shorter end-to-end delay and a higher packet delivery ratio in urban VANET communications.

Reliability is an important issue for safety-critical broadcast services in vehicular ad hoc networks (VANETs). So far, most investigations of such broadcast networks focus on multihop connectivity, taking all one-hop links for granted. In this paper, four reliability metrics for one-hop broadcast communication in VANETs, including the packet reception rate (PRR), the packet delivery ratio (PDR), the node successful packet delivery probability (PDP), and the effective range (ER), are introduced and evaluated analytically and by simulations. Expressions of these reliability metrics for one-hop broadcast in IEEE-802.11-based 1-D VANETs are derived with consideration of the IEEE 802.11 distributed coordination function (DCF), the hidden terminal problem, and collisions caused by concurrent transmissions. The impacts of network parameters such as distinct transmission, carrier sensing, and interference ranges; the density of nodes in the networks; the distances of receivers to the senders; the message generation rates; the backoff window sizes; and the channel data rates on the reliability of the broadcast communication in VANETs are investigated and discussed. As an example, the proposed model is applied to the evaluation of the dedicated short-range communication (DSRC) safety-critical message propagation in a highway setting. As a result, some important observations to the design and analysis of such communication systems are provided.

Vehicular Ad-hoc Network (VANET) communications are mobile communication alternatives allowing vehicles to exchange information among them with a suitable forwarding scheme. The forwarding scheme is a mechanism to select proper candidate nodes as the intermediate node. Current angle-based forwarding schemes take into account a Horizontal Relative Angle (HRA) and propose Vertical Relative Angle (VRA) as an alternative. The introduction of a filtering concept, implementing both HRA and VRA, restricts the number of insignificant candidates. Under various VANET communication factors (e.g., network density, mobility, and road level topology) the work presented here investigates the VRA scheme to improve the forwarding decision especially in the three-dimensional case within a large city environment.

VANETs are targeted to improve the traffic safety and driving experience on the road. Vehicular connectivity based communication in VANETs to be used for safety critical, safety related and non safety related messages dissemination in the networks. A key challenge in developing such network connectivity mechanism is that quickly adaptation the changes in the network topology due to the vehicular mobility. In this work we investigate the feasibility of developing the location based network connectivity for communication in VANETs in the spatial localized time domain for safety applications. The vehicular mobility and maximization of network connectivity duration between the vehicles have been identified as two important design goals in this work. However, these two goals are in conflict in nature, which makes it challenging to achieve both of these two goals in VANETs. To balance the trade-off between vehicular mobility and network connectivity, the average number of vehicle links, average link duration and connection time of each vehicle is ensured and subject to this constraint, aggregate network connectivity is maximized for efficient communication in VANETs.KeywordsMedium access control (MAC)Vehicular ad hoc networks (VANETs)Vehicular connectivity

A type of ad hoc network formed among moving vehicles that come in one another’s radio transmission range is called Vehicular Ad Hoc Network (VANET). VANET may be deployed using three architectures: pure ad hoc, WLAN and hybrid. Vehicle to Vehicle (V2V) and Vehicle to Infrastructure (V2I) are the two modes in VANET used for communication among vehicles. These features not only distinguish a VANET from other ad hoc networks but also make these networks more exposed to attacks and increase their complexity. These networks being the primary mechanism for communication in VANETs, appropriate and timely delivery of information is of prime importance. Due to the existence of various vehicular traffic scenarios, a single category of routing protocols is not sufficient for the VANETs. Therefore, various categories of routing protocols have been tailored to meet specific kinds of routing requirements in this framework. Most significant ones are ad hoc/topology-based, position-based, geocast-based, cluster-based, broadcast-based protocols. There exist a number of attacks that apart from affecting various other parameters also affect the routing protocols in these VANETs. Most of these attacks may be launched in all the above-mentioned three architectures. But, one of the most dangerous attacks is the Sybil attack that may be initiated in pure ad hoc deployment of VANET where vehicles communicate with one another in one to one manner using carry forward approach. In this paper, with the help of illustrative example for each of the five categories of routing protocols, we show how Sybil attack affects these protocols. Considering the ad hoc scenarios in VANETs, we also discuss a prevention mechanism for the Sybil attack briefly.

VANET (Vehicular Ad hoc Networks) enable on-road wireless communication using vehicular and road-based electronic infrastructure. The services provided include routine traffic information dissemination aimed at ensuring safe driving while offering payment systems, and entertainment services are also part of VANET services. Ensuring secure, cost-effective VANET communication is a key research focus. A mechanism for unidentified message transmission, reciprocal vehicular and road base verification, as well as highly secure authentication by a trusted party, preservation of confidentiality of messages, recovery of the identity of vehicle by a trusted authority in unfortunate events, and low set up cost, is the prerequisite for trusted vehicular communication in VANET. The technique of Chameleon hashing signature provides message security with frequent changing of keys. The validation of vehicular identity in group-based communication is centralized using group signature and time stamping. This study proposes a framework combining chameleon hash signatures with group signatures to enhance VANET communication privacy, security, and cost-effectiveness.

Vehicular Ad-hoc Networks (VANETs) offer immense potential for revolutionizing modern transportation systems through real-time communication and interaction between vehicles and roadside infrastructure. These networks can significantly enhance traffic management, improve safety, and support various vehicular services. However, ensuring secure communication in VANETs remains a critical challenge due to the highly sensitive nature of the data exchanged, such as location and personal information. Current authentication schemes, including the ANEL scheme, exhibit vulnerabilities like data interception and tracking risks. In this paper, we propose a novel, efficient, and lightweight authentication scheme that leverages elliptic curve cryptography (ECC) and message mapping techniques to address these security issues. The proposed solution strengthens encryption, enhances privacy protection, and mitigates risks such as unauthorized access and man-in-the-middle attacks. Furthermore, the scheme offers scalability and distinguishes between regular and priority users, making it adaptable to various VANET applications. This approach significantly improves the overall security and privacy framework of VANET systems while ensuring the efficient use of computational resources in vehicular environments.

Over the past few years, there has been significant research interest in field of vehicular ad hoc networks (VANETs). Wireless communication over VANETs supports vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I) communication. Such innovation in wireless communication has improved our daily lives through road safety, comfort driving, traffic efficiency. As special version of MANETs, VANETs bring several new challenges including routing and security challenges in data communication due to characteristics of high mobility, dynamic topology. Therefore, academia and the auto mobile industry are taking interest in several ongoing research projects to establish VANETs. The work presented here focuses on communication in VANETs with their routing and security challenges along with major application of VANETs in several areas.

Vehicular ad hoc network (VANET) plays a vital role in the intelligent transportation system (ITS). When a vehicle receives a message through network, the CRL (certificate revocation list) checking process will operate before certificate and signature verification. After successful authentication, a CRL list is created based on authentication. This CRL is used to verify whether a vehicle node can be permitted for communication in the VANET network. But when using CRL, a huge amount of storage space and checking time is needed. So we proposed a method without the CRL list. It mentions a key management list to overcome large storage space and checking time. Even it reduced the access delay. For access permission we can do an authentication system based digital novel signature authentication (DNSA) for each vehicle in the VANET with the RSU unit or with other participant node vehicles in the communication as per the topology. We can perform an efficient and secured communication in VANET.

Mobile Ad Hoc Networks (MANETs) have several features, such as dynamic topologies, limited bandwidth usage, limited energy, etc... Vehicular ad hoc networks (VANETs) are a special case of mobile ad hoc networks. VANET communication can be formed between vehicles with vehicle to vehicle (V2V) communication or between Vehicle-to-Road Side Units (V2R). VANETs provides a promising network scenario for facilitating safety on roads, managing traffic, and infotainment dissemination for both passengers and drivers. The communication between V2V and V2R is the most critical part, so a proper security and privacy methods have to be maintained. Messages are critical and important like a warning message, so that the message must be authenticated which guarantee's the message integrity. Elliptic Curve Digital Signature Algorithm (ECDSA) provides an efficient message authentication scheme. A combination of P2P, VANET and ECDSA can make the scenario more efficient and perform better in terms of time delay in message delivery.

Enormous applications which are enabled using Vehicular Ad Hoc Networks (VANETs) require a both efficient and reliable data delivery. Visible Light Communication (VLC), which has high transmission rate without using Radio Frequency (RF) spectrum, is regard as a candidate for data transmission in VANETs. Since a VLC system requires a line-of-sight communication, the position and the posture of LEDs and receivers play key roles in VLC. Unfortunately the position and the posture always change with vehicle motion and may make the performance of VLC become severe and even result in the outage of VLC. In this paper, we present an improved Vehicle-to-Vehicle (V2V) model and an improved Vehicle-to-Infrastructure (V2I) model in consideration of the position and the posture. In order to get diversity gains and reduce the VLC interruption caused by vehicle motion, we propose a VLC based cooperative diversity scheme. Finally simulation results show that the cooperative diversity scheme can decrease the Bit-Error-Rate (BER) significantly and reduce the VLC interruption caused by vehicle motion.

Recently, routing in Vehicular Ad hoc Networks (VANETs) has found significant attention. Besides, since these networks are highly dynamic and their topologies change rapidly, design of routing algorithms suitable for an urban environment is extremely challenging. Appropriate algorithms for urban environments could be opportunistic routing algorithms in which traffic transmission from source vehicles to destination vehicles is performed using the store-carry and forward mechanism. Most of the existing opportunistic routing algorithms use the flooding mechanism for increasing delivery ratio without considering the overheads of flooding. Thus, in order to reduce the overhead in these methods and improve the performance of routing in VANET, choosing an appropriate node to send messages and determining priority of messages for transmission will be very important. An efficient opportunistic routing (OR) mechanism, called Reliability-Aware Location and History Based Opportunistic Routing (RLHOR) is proposed in this paper for improving overhead. The RLHOR searches for a stable path by evaluating the stability of intermediate links based on lifetime of links, location and direction of intermediate vehicles, and history of intermediate vehicles in message delivery. Using the ONE simulator, our performance evaluation results show that the RLHOR operates better than conventional opportunistic routing algorithms. The RLHOR not only increases delivery rate, but also reduces network overhead, traffic loss, and number of aborted messages in sparse scenario.

Integration of IoT and edge cloud computing for smart microgrid energy management in VANET using machine learning

Information dissemination in vehicular ad hoc networks (VANETs) is inseparable from the interaction between vehicles and infrastructure. The trust authority (TA) often plays a pivotal role in VANETs and requires interaction with multiple vehicles. However, when the TA sends the same message to multiple vehicles, there are many redundancies, as it needs to negotiate with each vehicle and send them different ciphertexts. This greatly reduces the work efficiency of the TA. To the best of our knowledge, there is no research on the problem of redundancy that occurs when the same message is sent to multiple vehicles in VANETs. The proposed scheme adopts identity-based broadcast encryption (IBBE) technology, which is a secure data-sharing scheme suitable for the vehicle-to-infrastructure communication mode, in VANETs for the first time. Thus, with only one encryption, the TA can generate a fixed-length ciphertext for a group of vehicles. When there are new vehicles that subsequently request a service, the TA can assign encryption tasks to the proxy server. In terms of security, our scheme meets the particular requirements of VANETs. The encryption overhead of the sender and the length of the ciphertext were comparatively analyzed. The results demonstrated that the performance of the scheme improved significantly. Thus, our scheme can prevent redundancies and effectively improve the work efficiency of TA.

Road safety applications envisaged for vehicular ad hoc networks (VANETs) depend largely on the exchange of messages to deliver information to concerned vehicles. Safety applications as well as inherent VANET characteristics make data dissemination an essential service and a challenging task. We are developing a decentralized efficient solution for broadcast data dissemination through two game-theoretical mechanisms. Besides, VANETs can also include autonomous vehicles (AVs). AVs might represent a revolutionary new paradigm that can be a reality in our cities in the next few years. AVs do not need a driver to work; instead, they should copy a proper human behavior to adapt the driving according to the current circumstances, such as speed limit, pedestrian crossing street or wheather conditions. We will develop an AV software module including artificial intelligence (AI) techniques so that AVs can interact with the dynamic scenario throughout time. Finally, we also will include electrical vehicles (EV) in the VANET, so that special services such as finding and reserving an EV charging station place will be welcome. In addition, we are developing a multimetric geographic routing protocol for VANETs to transmit H.265 video (traffic accident, traffic state, commercial….) over VANETs.