Message Dissemination Schemes Research Articles

A hybrid relay node selection scheme for message dissemination in VANETs

Over the past few years, there has been growing research interests on vehicular ad hoc networks (VANETs) due to their ease of deployment and the potential support for wide range of applications that can greatly enhance our everyday driving experience. Multi-hop messaging is expected to be the primary mode of communication among vehicles in numerous VANET-based applications including road safety, traffic management and infotainment services. Proper selection of the next-hop relay nodes is an essential part in the design of multi-hop message dissemination schemes in VANETs, which highly governs the reception of the broadcasted messages, especially when evaluated over large coverage distances and high node density networks. Existing message dissemination schemes adopt only a single relay nodes selection criterion for choosing nodes in the group of next-hop relays. However, potential of the selected relay nodes can be restricted due to exploiting only a single selection criterion, hence limiting the performance outcomes. This research proposes a new class of hybrid relay nodes selection scheme that attempts to exploit the best features of existing message dissemination protocols, in terms of message reachability, communication delay and bandwidth utilization, while avoiding their shortcomings. The new hybrid scheme takes into account the spatial distribution of the next-hop relay nodes with reference to the current sending node. To the best of our knowledge, the present study is the first in literature to propose such a hybrid scheme that attempts to improve performance of VANETs over varying node densities, traffic load conditions and mobility speed scenarios. Over the most stringent communication scenario considered in this work, our performance analysis indicates that the new hybrid scheme improves reachability by up to 10% compared to the most competitive conventional versions. This improvement is obtained while having a marginal performance fall in terms of the end-to-end communication delays and messages saved rebroadcast ratios.

An Adaptive Link Quality-Based Safety Message Dissemination Scheme for Urban VANETs

In urban vehicular ad hoc networks (VANETs), signal propagation experiences severe attenuation from obstacles especially at intersections. Multi-hop broadcast schemes are often used to disseminate safety messages to region of interest. However, existing multi-hop broadcast schemes either neglected the impact of realistic physical channels or just considered part of it. In this letter, we propose a link quality-based safety message dissemination scheme for urban VANETs. A comprehensive physical channel connectivity calculation method is proposed for accurately estimating the connectivity probability among vehicles. A score-based priority allocation mechanism for candidate forwarders (CFs) is proposed to coordinate the contention among CFs. Finally, we calculate the minimum waiting time and contention window size for each vehicle in CFs. Simulation results show that our proposed scheme outperforms existing multi-hop broadcast schemes for urban VANETs.

A Joint Control–Communication Design for Reliable Vehicle Platooning in Hybrid Traffic

Recent studies have shown that traffic safety and efficiency can be substantially improved by vehicle platooning , in which vehicles periodically broadcast their kinetic status to neighbors, known as beacon message dissemination . As a networked control system, vehicle platoon has attracted significant attention from both the control and networking areas. However, few studies consider the practical traffic scenario with both platoons and individual vehicles, and the proposed beaconing schemes lack the deep understanding of relationship between the beaconing performance and the requirements of the control mechanism. To address these challenging issues, we propose a joint control–communication design to achieve reliable vehicle platooning in a more realistic traffic scenario, wherein the traffic consists of both platoons and individual vehicles, and both periodic beacon messages and event-based safety messages shall be delivered together. Specifically, we first develop a comprehensive control-theoretical analysis to understand how the vehicular communication can affect features of platoon driving; based on the understanding, we then propose and analyze an adaptive platoon-based message dissemination scheme; finally, we conduct extensive numerical experiments to validate the effectiveness of the protocol and to confirm the accuracy of the our theoretical analysis.

SEMD: Secure and efficient message dissemination with policy enforcement in VANET

Vehicular ad hoc network (VANET) is an increasing important paradigm, which not only provides safety enhancement but also improves roadway system efficiency. However, the security issues of data confidentiality, and access control over transmitted messages in VANET have remained to be solved. In this paper, we propose a secure and efficient message dissemination scheme (SEMD) with policy enforcement in VANET, and construct an outsourcing decryption of ciphertext-policy attribute-based encryption (CP-ABE) to provide differentiated access control services, which makes the vehicles delegate most of the decryption computation to nearest roadside unit (RSU). Performance evaluation demonstrates its efficiency in terms of computational complexity, space complexity, and decryption time. Security proof shows that it is secure against replayable choosen-ciphertext attacks (RCCA) in the standard model.

An Efficient Message Dissemination Technique in Platooning Applications

Autonomous driving in road trains, a.k.a. platooning, may reduce fuel consumption considerably if the inter-vehicle distances are kept short. However, to do this, the intra-platoon communication must not only be reliable but also able to meet strict deadlines. While time-triggered messages are the foundation of most distributed control applications, platooning is likely to also require dissemination of event-driven messages. While much research work has focused on minimizing the age of periodic messages, state-of-the-art for disseminating event-driven messages is to let all nodes repeat all messages and focus on mitigating broadcast storms. We derive an efficient message dissemination scheme based on relay selection which minimizes the probability of error at the intended receiver(s) for both unicast and broadcast, without degrading the performance of co-existing time-triggered messages. We present a full analysis of the resulting error probability and delay, when relayers, selected by our algorithm, are used to disseminate messages within a platoon. Numerical results indicate that the proposed relaying policy significantly enhances the reliability for a given delay.

A Warning Message Dissemination Scheme with User Privacy and Message Integrity for VANET

Vehicular ad hoc networks (VANETs) are wireless networks which are infrastructure-less in nature because of the highly mobile nodes (vehicles) in the network. Warning message dissemination can be considered as the primary application of VANET, where in alert messages need to be quickly as well as smartly disseminated in the network to make it available for a large number of vehicles. A scheme will be effective once it reaches to maximum number ofvehicles with minimum overhead and delay, for attaining the same a broadcast scheme is familiarized in this paper along with user privacy and message integrity. User privacy is an added advantage for all the participating vehicles which makes the system more acceptable as a whole. Protecting the privacy of users leads to undesirable tracking of vehicles by attackers. A part from user privacy, message integrity is also been guaranteed in the proposed scheme. Integrity of the message can be checked in order to confirm whether the received alert is genuine. This paper presents a warning message dissemination scheme along with the mechanisms to ensure user privacy and message integrity.

Using topology and neighbor information to overcome adverse vehicle density conditions

Vehicular networks supporting cooperative driving on the road have attracted much attention due to the plethora of new possibilities they offer to modern Intelligent Transportation Systems. However, research works regarding vehicular networks usually obviate assessing their proposals in scenarios including adverse vehicle densities, i.e., density values that significantly differ from the average values, despite such densities can be quite common in real urban environments (e.g. traffic jams). In this paper, we study the effect of these hostile conditions on the performance of different schemes providing warning message dissemination. The goal of these schemes is to maximize message delivery effectiveness, something difficult to achieve in adverse density scenarios. In addition, we propose the Neighbor Store and Forward (NSF) scheme, designed to be used under low density conditions, and the Nearest Junction Located (NJL) scheme, specially developed for high density conditions. Simulation results demonstrate that our proposals are able to outperform existing warning message dissemination schemes in urban environments under adverse vehicle density conditions. In particular, NSF reduces the warning notification time in low vehicle density scenarios, while increasing up to 23.3% the percentage of informed vehicles. As for high vehicle density conditions, NJL is able to inform the same percentage of vehicles than other existing approaches, while reducing the number of messages up to 46.73%.

Evaluating the impact of a novel message dissemination scheme for vehicular networks using real maps

In traffic safety applications for vehicular ad hoc networks (VANETs), some warning messages have to be urgently disseminated in order to increase the number of vehicles receiving the traffic warning information. In those cases, redundancy, contention, and packet collisions due to simultaneous forwarding (usually known as the broadcast storm problem) are prone to occur. In the past, several approaches have been proposed to solve the broadcast storm problem in multi-hop wireless networks such as Mobile ad hoc Networks (MANETs). Among them we can find counter-based, distance-based, location-based, cluster-based, and probabilistic schemes, which have been mainly tested in non-realistic simulation environments. In this paper, we present the enhanced Message Dissemination based on Roadmaps (eMDR), a novel scheme specially designed to increase the percentage of informed vehicles and reduce the notification time; at the same time, it mitigates the broadcast storm problem in real urban scenarios. We evaluate the impact that our scheme has on performance when applied to VANET scenarios based on real city maps, and the results show that it outperforms previous schemes in all situations.

Modeling gossip-based content dissemination and search in distributed networking

This paper presents a rigorous analytic study of gossip-based message dissemination schemes that can be employed for content/service dissemination or discovery in unstructured and distributed networks. When using random gossiping, communication with multiple peers in one gossiping round is allowed. The algorithms studied in this paper are considered under different network conditions, depending on the knowledge of the state of the neighboring nodes in the network. Different node behaviors, with respect to their degree of cooperation and compliance with the gossiping process, are also incorporated. From the exact analysis, several important performance metrics and design parameters are analytically determined. Based on the proposed metrics and parameters, the performance of the gossip-based dissemination or search schemes, as well as the impact of the design parameters, are evaluated.