In the recent years, we are witnessing a growing interest into the design of smart vehicles and smart roads for Intelligent transportation systems. Vehicles as part of the Internet of Things should provide to the driver and passenger with a variety of services using efficient gateway discovery mechanism while maintaining a certain level of security and authentication to avoid potential malicious attacks. In this paper, we propose a secure hybrid adaptive gateway discovery and communication protocol for smart vehicular networks, which we refer to as SEGAL. Our proposed SEGAL protocol is based upon building a secure clustered vehicular network, and permits the exchange of gateway discovery messages through authenticated clusterheads and cluster members. We shall present the design of our protocol, and describe how it can overcome the possible malicious attacks that might harm the network. Then, we report its efficiency and scalability using an extensive set of simulation experiments using Ns-2 simulator. Our results indicate that the proposed SEGAL protocol is scalable while achieving high success rate, low response time and dropping rate. Copyright © 2016 John Wiley & Sons, Ltd.

A great interest in vehicular ad-hoc networks has been noticed by the research community. General goals of vehicular networks are to enhance safety on the road and to ensure the convenience of passengers by continuously providing them, in real time, with information and entertainment options such as routes to destinations, traffic conditions, facilities' information, and multimedia/Internet access. Indeed, time efficient systems that have high connectivity and low bandwidth usage are most needed to cope with realistic traffic mobility conditions. One foundation of such a system is the design of an efficient gateway discovery protocol that guarantees robust connectivity between vehicles, while assuring Internet access. Little work has been performed on how to concurrently integrate load balancing, quality of service (QoS), and fault tolerant mechanisms into these protocols. In this paper, we propose a reliable QoS-aware and location aided gateway discovery protocol for vehicular networks by the name of fault tolerant location-based gateway advertisement and discovery. One of the features of this protocol is its ability to tolerate gateway routers and/or road vehicle failure. Moreover, this protocol takes into consideration the aspects of the QoS requirements specified by the gateway requesters; furthermore, the protocol insures load balancing on the gateways as well as on the routes between gateways and gateway clients. We discuss its implementation and report on its performance in contrast with similar protocols through extensive simulation experiments using the ns-2 simulator. Copyright (c) 2013 John Wiley & Sons, Ltd.

In recent years, we have witnessed a growing interest in Vehicular Networks from both the research community and industry. Several potential applications of Vehicular Networks are envisioned such as road safety and security, streaming services, traffic monitoring and driving comfort, just to mention a few. It is critical that the existence of convenience or driving comfort services do not negatively affect the performance of safety services. In essence, the dissemination of safety services or the discovery of convenience applications require the communication among service providers and service requesters through constrained bandwidth resources. Therefore, service discovery techniques for vehicular networks must efficiently use the available common resources. In this paper, we present a bandwidth-efficient and scalable hybrid adaptive service discovery protocol (VSDP) for Vehicular Networks. VSDP aims at providing high success ratio while guaranteeing low response time and good scalability when the number of requests increases. Our proposed protocol finds the service provider and its routing information simultaneously which results in overall bandwidth savings. It uses diverse channels to exchange discovery and routing packets, thereby decreasing the congestion on single channels and decreasing the delay of service discovery. Our proposed service discovery protocol adapts the advertisement zone size of service providers based on an efficient adaptation mechanism that takes into consideration network condition and application requirements. The adaptation process is based on an adjustment technique and a prediction technique. We discuss the implementation of our protocol, present its proof of correctness as well as the performance evaluation through an extensive set of simulation experiments and using different mobility models. Our results show the scalability of our protocol. They indicate that our techniques can achieve significant success rate (more than 90 percent), while guaranteeing low response time (in the order of milliseconds) and low bandwidth usage when compared to existing service discovery techniques.

Leader election problem has been studied in the past to improve the efficiency of both distributed systems and wireless ad hoc and sensor networks. Yet, few research has been done on the leader election process for wireless mesh networks. Most of the existing leader election protocols consider wireless networks in general, without focusing on the particularities of mesh networks. Thus, these protocols are not suitable for wireless mesh networks. The lack of research on this issue has motivated us to design a leader election protocol dedicated to wireless mesh networks. In this work, we propose an efficient leader election protocol for wireless mesh network, which is based on the construction of a spanning tree that includes all wireless mesh routers. The protocol elects the node with the longest remaining battery life. In this paper, we give a detailed description of the proposed protocol, prove its correctness, discuss its message and time complexities and then evaluate its performance through simulation using ns-2. We show that our protocol is efficient and scales well with the increase in number of mesh routers and mesh clients.

ABSTRACTIntelligent transportation systems have attracted many researchers. These latter have invested much effort to develop many applications and services mainly for vehicular systems. Services can be classified as safety or convenience services. A service discovery mechanism is needed to permit the discovery and the interaction with the existing services. However, so far security issues for service discovery in vehicular systems have not been widely considered, mainly for the convenience type of applications. Thus, a secure service discovery and communication protocol is necessary to prevent from many attacks and malicious processes in the vehicular system. In this paper, we investigate the possible attacks that can occur during the service discovery and communication processes. Then, we present our proposed group‐based authentication scheme for secure service discovery and communication in vehicular systems. Our proposed scheme is mainly dedicated for the convenience type of applications. We discuss the security requirements achieved by our proposed protocol and we report on its performance evaluation. We prove through our extensive set of simulations that our proposed scheme achieves a high success rate for the secure discovery of services, while maintaining the scalability of the network and low discovery delays. Copyright © 2013 John Wiley & Sons, Ltd.

Recently we have witnessed a growing interest in Vehicular Ad hoc Networks from the ITS community. Several potential applications of Vehicular Networks aiming at integrating service discovery mechanisms and the latest Internet access technologies are envisioned. However, several challenging issues, such as gateway discovery among others, remain to be resolved before VANET technology becomes a commodity. Indeed, in this case, it is very essential to provide clients with gateway services that better suit their requests while balancing the load on the gateways, in order to reduce the gateways congestion problem. In this paper, we propose to evaluate the performance of a load balanced and introduce a new QoS gateway discovery protocol (Collaged) that permits the connection to heterogeneous wireless networks. The protocol guarantees balancing the load at the gateways levels, as well as the routing paths between gateways and gateway requesters. It also permits gateway requesters to choose and connect to the gateways that satisfy the QoS required by the vehicles. We present our protocol, and discuss its performance evaluation using an extensive set of simulation experiments. Our results indicate that significant improvement were achieved using QoSLAGAD protocol when compared to LAGAD while guaranteeing QoS and balancing the gateways' load.

Gateway discovery in vehicular networks is very important in order to permit the connection to the Internet or to heterogenous networks. Fault tolerance, load balancing, and QoS are very important aspects to enhance the performance of the network and the satisfaction of the clients. None of the existing gateway discovery protocols for vehicular networks has been designed while taking into account these aspects at the same time. In this paper, we propose our fault tolerance, load balancing, and QoS based service discovery protocol for vehicular network and we prove its correctness.

Recently, vehicular networks and inter-vehicle communication have received attention from the research community and the automotive industry. In this context, many services are deployed in vehicular networks that are beneficial to drivers and passengers. Service discovery in vehicular networks is vital to make such services useful. However, due to the lack of communication reliability in vehicular ad hoc networks, it is necessary to implement fault-tolerant techniques during the discovery of service providers in vehicular networks. Very few service discovery protocols for vehicular networks have considered fault tolerant techniques, which are very important for the efficiency of service discovery. Fault tolerant techniques improve service request satisfaction and reduce dropped connections due to faulty components between the service provider and the service requester. In this paper, we propose a fault tolerant location based service discovery protocol for vehicular networks which can work well under service provider failures, communication link failures and roadside router failures. Our protocol permits the discovery of location based services where the requester specifies the region of interest within the request. Our protocol uses an infrastructure support consisting of clusters of roadside routers formed in specific regions in the vehicular network. In addition, service discovery messages are integrated into the network layer and use channel diversity in order to improve service discovery efficiency. We describe our fault tolerant location based vehicular service discovery protocol (FTLocVSDP) and discuss its proof of correctness and performance evaluation. We prove that the success rate is improved in the roadside router failure and in the communication link failure scenarios by 50% and 30%, respectively, compared to the location based service discovery protocol for vehicular networks (LocVSDP) which does not consider fault tolerant techniques.

Internet access from vehicular networks is a very promising subject that needs to be investigated from the research community. Vehicles should be able to connect to the Internet, and provide drivers and passengers with a high number of services that need communication through gateways. Existing discovery protocols in VANets did not focus on secure gateway discovery in particular, but they considered the discovery of secure services in general. In this paper, we propose a secure hybrid adaptive gateway discovery and communication system for VANets that we call SEGAL. Our proposed SEGAL protocol aims to provide an efficient and secure gateway advertisement and discovery process for VANets. It is hybrid because it combines both proactive and reactive discovery approaches. Besides, it is adaptive because it shrinks or extends the advertisement zone of the gateway for scalability purposes. Our proposed protocol builds a secure clustered VANet and permits the exchange of gateway discovery messages through authenticated clusterheads and cluster members. We discuss the design of our protocol, and how it can overcome the possible attacks that can occur. Then we prove its efficiency and scalability in our performance evaluation. We show that our proposed SEGAL achieves high success rate, low response time and dropping rate, while maintaining the scalability in the VANet.

Service discovery studies in vehicular networks that guarantee QoS requirements to service requesters are very important. To the best of authors' knowledge, none of the existing service discovery protocols in vehicular networks have been provided in the literature that guarantee QoS to service requesters and to the vehicular network. For efficient service discovery in vehicular networks, it is very important to provide users with services that suit better to their requests while balancing the load on service providers. Moreover, for service discovery protocol integrated with routing protocols, it is important to guarantee load balancing on routing paths between service providers and service requesters. In this article, we present a QoS aware location-based service discovery protocol for vehicular networks. Our protocol guarantees load balancing on service providers, and routing paths between service providers and service requesters. It permits also to choose service providers and routing paths between service providers and service requesters that satisfy some performance attributes specified by service requesters. We present our QoS aware protocol, prove its correctness, report on its performance evaluation, and discuss our experimental results we have obtained using realistic scenarios.

Recent advances in Intelligent Transportation Systems (ITS) and the growing number of applications in Vehicular Networks (VN) have attracted many researchers. Applications in Vehicular Networks comprise but are not limited to safety applications and convenience applications. Deploying Vehicular Networks widely cannot be accomplished without overcoming the existing research challenges in such networks. Service discovery is one of the main challenges in Vehicular Networks which are characterized by their large scale and high mobility. Existing service discovery techniques for ad hoc networks cannot be applied directly to Vehicular Networks scenarios due to their poor performance and decreased efficiency in Vehicular Networks. In this paper, we present our location-based service discovery protocol for Vehicular Networks (LocVSDP). Our protocol permits the discovery of location-aware and timesensitive services in Vehicular Networks. Moreover, our LocVSDP protocol improves service discovery efficiency by integrating service information into the network layer and using diverse channels. In our protocol, we present our efficient mechanism that permits to service requesters to find service providers and their routing information simultaneously, which results in overall bandwidth savings. We make use of diverse channels for the exchange of discovery and routing packets, which decreases the congestion on single channels and improves the delay of service discovery. Then, we present our efficient location-based request propagation and an efficient computation of the service reply, based on the specified location of the requested service in the drivers request. We discuss the implementation of our protocol and present its proof of correctness.

The increasing number of potential applications related to intelligent transportation systems (ITSs) have attracted researchers to the area of vehicular networks (VNs). Two main classes of applications have lately gained popularity, i.e., security and safety, and traffic information and service location applications. However, several open research challenges are delaying the efficient and widespread deployment and management of such applications in VNs. One of these challenges comprises how vehicles and service providers could discover each other in VNs, which are well known for their large scale and high mobility. Most service discovery strategies available present high overhead and poor performance in a VN environment. Existing context-aware and location-based service discovery protocols (LocVSDPs) are either designed without considering the particularities of VNs or are not scalable with the increase in network density and the number of requests. In this paper, we propose a new context-aware and LocVSDP (EB-LocVSDP) for VNs and its variant (Naive-LocVSDP). Our protocols offer a scalable framework for the discovery of time-sensitive and location-based services in VNs. They rely on a cluster-based infrastructure. Furthermore, LocVSDPs are integrated into the network layer and use channel diversity to improve service discovery efficiency. We discuss the implementation of our protocols and techniques, report on performance evaluation experiments, and offer a comparison against an existing location-based discovery protocol [the Vehicular Information Transfer Protocol (VITP)]. Our simulation results indicate that our proposed LocVSDPs show a gain of 20% in terms of success rate. LocVSDPs use at least 90% less bandwidth than VITP, and their average response time is at least 10% lower than VITP for successful query transactions.

Intelligent Transportation Systems (ITS) are gaining momentum among researchers. ITS encompasses several technologies, including wireless communications, sensor networks, data and voice communication, real-time driving assistant systems, etc. These states of the art technologies are expected to pave the way for a plethora of vehicular network applications. In fact, recently we have witnessed a growing interest in Vehicular Networks from both the research community and industry. Several potential applications of Vehicular Networks are envisioned such as road safety and security, traffic monitoring and driving comfort, just to mention a few. It is critical that the existence of convenience or driving comfort services do not negatively affect the performance of safety services. In essence, the dissemination of safety services or the discovery of convenience applications requires the communication among service providers and service requesters through constrained bandwidth resources. Therefore, service discovery techniques for vehicular networks must efficiently use the available common resources. In this thesis, we focus on the design of bandwidth-efficient and scalable service discovery protocols for Vehicular Networks. Three types of service discovery architectures are introduced: infrastructure-less, infrastructure-based, and hybrid architectures. Our proposed algorithms are network layer based where service discovery messages are integrated into the routing messages for a lightweight discovery. Moreover, our protocols use the channel diversity for efficient service discovery. We describe our algorithms and discuss their implementation. Finally, we present the main results of the extensive set of simulation experiments that have been used in order to evaluate their performance.

Intelligent Transportation Systems (ITS) have attracted many researchers that invested a lot of effort to develop many applications mainly for vehicular systems. Existing and investigated applications in vehicular systems are classified in two folds: safety applications and convenience applications. The first type of applications focuses mainly on drivers security and safety on the roads by providing warnings and alerts if there are accidents or disasters. The second type of applications helps drivers and passengers to localize services, get accurate weather or road condition information, get entertainment access, or even interact with surrounding services. Thus, a secure service discovery and communication protocol is mandatory in order to prevent from many attacks and malicious processes in the vehicular system. An efficient service discovery protocol should guarantee a secure discovery and communication in the vehicular system while maintaining the network scalability and a low communication delay. In this paper, we present the possible attacks that can happen at the discovery level and at the routing level. Then, we present our secure service discovery protocol for vehicular systems designed for the convenience type of applications. We prove the correctness of our proposed scheme and we compute its message complexity.

Recent studies on service discovery protocols in vehicular networks have shown promising results. However, very little work has been reported on how to integrate the fault tolerance and QoS features into service discovery protocols. These features are vital for the success of the deployment of service discovery protocols in vehicular networks. Drivers on their cars should not have their requests dissatisfied or their connections dropped because a service provider or some components between the service provider and the service requester have failed. Moreover, it is very important to provide users with services that suit better to their requests while balancing the load on service providers. In addition, for a service discovery protocol integrated with routing protocols, it is important to guarantee load balancing on routing paths between service providers and service requesters. In this paper, we present a QoS and fault tolerant location based service discovery protocol for vehicular networks. The main advantages of our protocol is its ability to tolerate service providers failure, communication links failure and roadside routers failure. Moreover, our protocol guarantees load balancing on service providers, and routing paths between service providers and service requesters. It permits also to choose service providers and routing paths between service providers and service requesters that satisfy some performance attributes specified by service requesters. We present our fault tolerance and QoS based service discovery protocol in vehicular networks, and report on its performance evaluation. Our simulation experiments show that our proposed QoS and fault tolerant based location based service discovery algorithm improves the success and connection rates significantly over the original LocVSDP.

The number of applications in Intelligent Transportation Systems (ITS) is growing rapidly. Vehicular systems have been widely seen as a promising technique for ITS-based applications. Two main types of applications are considered in vehicular systems: safety and infotainment applications. While the first type of applications provides drivers with warning or alert messages to prevent them from an accident or a disaster, the second type of applications allows drivers and passengers to localize services, get information, and even perform transactions with the surrounding services. Thus, it is very important to have secure discovery and communication with these services, while not affecting drastically the communication delay and the network scalability. In this paper, we discuss the importance of secure service discovery and communication in vehicular systems. Then, we propose a secure service discovery protocol for vehicular systems dedicated mainly to the infotainment type of application. We discuss the security requirements achieved by the proposed protocol and we report on its performance evaluation.

Intelligent transportation systems (ITSs) are gaining momentum among researchers. ITS encompasses several technologies, including wireless communications, sensor networks, voice and data communication, real-time driving-assistant systems, etc. These state-of-the-art technologies are expected to pave the way for a plethora of vehicular network applications. However, ITS faces difficult issues when trying to widely deploy such networks and applications. The interconnection of different networks, even in the case of the Internet, is one of the main difficulties that is delaying the wide spread of vehicular networks. In this paper, we present a novel gateway discovery technique for vehicular ad hoc networks (VANets). Our protocol aims to provide an efficient hybrid adaptive Location-Aided Gateway Advertisement and Discovery (LAGAD) mechanism for VANets. First, it permits gateway clients to discover nearby gateways; then, gateways keep advertising themselves to their clients to permit client information about the route toward the discovered gateway without having to resort to reactive route discovery. We discuss the implementation of our algorithm and present its proof of correctness, in addition to the performance evaluation demonstrated through an extensive set of simulation experiments using a Manhattan mobility model. Our results indicate that our LAGAD scheme is scalable and that a significant success rate could be achieved using our algorithm while guaranteeing low response time (on the order of milliseconds) and low bandwidth usage when compared with other gateway discovery approaches. Moreover, our results indicate that LAGAD achieves a high delivery ratio of data packets, as well as a low end-to-end delay, and permits duplicate and ordered data packet reception at the destination gateway.

Recent studies on service discovery protocols in vehicular networks have shown promising results. However, very little work has been reported on how to integrate the fault tolerance feature into these mechanisms. This feature is vital for the success of the deployment of service discovery protocols in vehicular networks. Drivers on their cars should not have their requests dissatisfied or their connections dropped because a service provider or some components between the service provider and the service requester have failed. In this paper, we present a fault tolerant location based service discovery protocol for Vehicular Networks. The main advantages of our protocol is its ability to tolerate service providers failure, communication links failure and roadside routers failure. We present our fault tolerant protocol, and report on its performance evaluation. Our simulation experiments show that our proposed fault tolerant LocVSDP algorithm improves the success rate significantly over the basic LocVSDP. In fact, the success rate is improved in the roadside routers failures scenario and in the links failures scenarios by 50 percent and 30 percent respectively.

A considerable number of Vehicular Network (VN) applications have been developed recently. These applications range from security and safety to traffic information and service location. However, several research challenges remain open concerning efficient service discovery in large scale VNs. Most of the existing service discovery strategies present high overhead and poor performance when applied to VNs. Furthermore, existing context-aware and location-based service discovery protocols are either designed without considering the particularities of VNs or are not scalable with the increase of network density and number of requests. In this paper, we present novel context-aware and location-based service discovery protocols (Election-Based LocVSDP and Naive LocVSDP) that offer a scalable framework for the discovery of time-sensitive and location based services in large scale VNs. We conduct a concrete set of simulation experiments to evaluate the performance of our techniques and compare the results with an existing location-based discovery protocol (VITP). Simulation results indicate that our techniques outperform the VITP protocol in terms of success rate, average response time and bandwidth usage. In essence, both LocVSDP protocols show a gain of 20 percent in terms of success rate, use at least 90 percent less bandwidth than VITP and their average response time is at least 10 percent lower than VITP for successful query transactions.