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The location verification of the vehicles interacting during the process of communication needs to be cooperatively determined under Non Line Of Sight (NLOS) situations for facilitating risk free environment with the least degree of congestion. The vehicular nodes in NLOS conditions possess the possibility of introducing channel congestion and broadcast storm into the network either intentionally or unintentionally during the event of emergency message dissemination in the vehicular network. Thus, the NLOS vehicular nodes of the network need to be detected through direct interaction and neighbourhood collaboration such that the rate of emergency message dissemination is sustained to the maximum degree. In this paper, a Rank Criteria Improved Confidence-based Centroid Scheme (RCICCS) is proposed for potential localization of NLOS nodes. This proposed RCICCS scheme uses an integrated cost, computed using the primitive cost and penalty cost in order to increase the effectiveness in localizing NLOS nodes. Thus effective location of NLOS nodes is determined based on rank criterion-based neighbor confidence measure that are iteratively enhanced during the process of perturbation using the method of gradients. The experimental analysis of the proposed RCICCS scheme confirmed a remarkable enhancement rate of emergency message delivery and neighbourhood awareness under NLOS conditions.

The dissemination of road safety messages is a challenging task in VANETs. Indeed, they should be efficiently transmitted by achieving a high packet delivery within a limited transmission delay and a minimum of overhead. In order to meet these constraints, while overcoming the data dissemination challenges, researchers have proposed a wide variety of solutions. Most of these solutions are addressing the well-known Broadcast Storm problem. In this context, we propose in the current work a new dissemination strategy denoted “READ” for robust and efficient adaptive data dissemination protocol. On the one hand, the originality of this protocol lies in its robustness that is achieved through a smart relay selection. Therefore, a high data reliability is guaranteed based on a beaconless strategy while taking into account the surrounding vehicles’ density. On the other hand, the protocol efficiency is manifested through the effective use of the limited network resources by reducing the excessive number of redundant messages. The simulation results show that the proposed solution achieves a high data reachability within a low transmission delay while using the minimum network resources. Furthermore, READ presents an adaptive feature that makes it suitable either for safety applications or for comfort application.

Cyber-physical system (CPS) provides a well-organized integration between communication , computation , and control (3C) technologies. CPS has been widely used in the vehicular networks and it requires to discover multimodal data from the physical system to make appropriate decisions and actions, for example, congestion warnings, applying brakes, adjusting speed limits, etc. Information discovery and availability at individual network elements is one of the fundamental foundations of CPS. In this paper, we proposed two multimodal network information discovery schemes for vehicular CPS using the Named Data Networking (NDN). One of the proposed schemes simply modifies the pull-based NDN communication mechanism to discover multimodal multi-hop data from the network and the other scheme uses the Interest broadcast suppression (IBS) mechanism. The proposed Interest broadcast suppression scheme adapts the holding time technique to defer the Interest forwarding and its computation involves the hop-count, distance, and other network parameters. Simulation results show that the proposed schemes discover about 172 and 162 percent more multimodal information from approximately 283 and 210 percent more network area by suppressing approximately 50 percent of the Interest broadcast storm in highway and the urban traffic scenarios, respectively.

Vehicular Ad hoc Network (VANET) is one of the subset of Mobile Ad hoc Network (MANET) and it is a self-organised system with a group of vehicles, which are capable of short-range communication using On Board Unit (OBU). This unit is comprised with the vehicles that are possible to communicate with the nearby vehicles. VANETs rely on heavy broadcast transmission due to sharing data (messages) between the nearby vehicles about the traffic, collision and so on. This redundant information spoils the nature of VANET that affects the inter-vehicular communication, rebroadcasting and information on collision. This message transmission increases largely as the number of vehicles increases. This problem is typically named as broadcast storm and it is relatively reduced through the proposed Selective Reliable Communication (SRC) Protocol. Through a reliable communication, packets are retransmitted to reduce a number of transmission in the network within the acceptable level of QoS. The proposed SRC protocol automatically detect the vehicle clusters as “Zone of Interest”. Generally, the proposed protocol forwards the packets to the cluster-heads and the cluster-head forwards the packets to the cluster-members. The proposed protocol outperforms than the existing protocols in terms of Throughput, Packet Delivery Ratio (PDR) and Average delay.

A Vehicular Ad-hoc Network (VANET) is a subclass of wireless ad-hoc networks, widely used in on-road vehicles and roadside equipment, having applications in various areas including passenger safety, smart traffic solutions, and connectivity on vehicles The VANET is the backbone of the Intelligent Transport System (ITS) that establishes connectivity between vehicles through a wireless medium. When it comes to the communication between high-speed vehicles there is the challenge of dynamic mobility. In order to provide a higher Packet Delivery Ratio (PDR) and increase the throughput, a new routing protocol called Dynamic Trilateral Enrolment (DyTE) is introduced which chooses a dynamic trilateral zone to find the destination vehicle by allowing only relevant nodes to participate in the communication process using the location coordinates of source and destination nodes. The proposed routing protocol is compared with Ad-hoc On-demand Distance Vector (AODV), Ad-hoc On-demand Multipath Distance Vector (AOMDV), and Dynamic Source Routing (DSR), and the results show remarkable improvement in reducing the Network Routing Load (NRL) and increasing the PDR and throughput of the network. DyTE has performed more efficiently in terms of PDR (23% approximately), throughput (26% approximately) and drastically minimized the NRL by a factor of almost 3.

NDN is an important instance of Information-Centric Networking. When integrating NDN into MANET, exploring new routing is a necessary task for this research area. The LSAs flooding is a common method to obtain network topology during route establishment. However, the LSAs flooding often results in a broadcast storm in high-density MANET. Using the MPR set proposed in the OLSR can effectively reduce the number of LSAs in the process of route establishment and can further solve the broadcast storm. In this paper, an enhanced neighbor discovery protocol firstly is designed to establish a MPR set. The new protocol can effectively avoid the problem incurred by unidirectional links that impact the network performance in a wireless environment. And then a new and proactive routing NOLSR based on OLSR for NDN-MANET is proposed to support NDN in MANET. And another important work is that NOLSR is implemented on top of NDN Forwarding Daemon NFD. Finally, we make a comparative analysis between NOLSR and the two most relative schemes such as traditional LSA-flooding and the scheme [1] by emulation experiments in the NDN emulator mini-NDN.

Today, unmanned aerial vehicles (UAVs), also known as drones, have become very popular in military applications, commercial applications, and academic research. Flying ad hoc network (FANET) is a new type of ad hoc network, which groups small drones into an ad hoc form. These networks have unique characteristics, including moving in a 3D space, high mobility, frequent topological changes, limited resources, low density of nodes, and so on, which impose various challenges when designing a proper and efficient routing scheme. In this paper, we present a fuzzy logic-based routing scheme for flying ad hoc networks. The proposed routing scheme has two phases: route discovery phase and route maintenance phase. In the first phase, we propose a technique for calculating the score of each node in the network to prevent the broadcast storm problem and control the flood of the control messages, which have been broadcast to discover a new route in the network. This score is calculated based on various parameters such as movement direction, residual energy of nodes, link quality, and node stability. Moreover, in the route selection process, we design a fuzzy system to select routes with more fitness, less delay, and fewer hops for data transfer. The second phase includes two steps: preventing route failure in order to detect and modify paths at the failure threshold, and reconstructing failed routes in order to recognize and quickly replace these routes. Finally, the proposed routing scheme is implemented in NS2 to evaluate its performance and determine its efficiency. The simulation results are compared with three routing methods, namely ECaD, LEPR, and AODV. These results show that the proposed routing method outperforms other routing schemes in terms of end to end delay, packet delivery rate, route stability, and energy consumption. However, it has slightly increased the routing overhead.

Vehicular named data networking (VNDN) has the data-centric and in-network caching advantages that are in line with the requirements of multi-hop content retrieval in vehicular ad hoc networks (VANETs). Some current restrictive forwarding strategies utilize single-path forwarding to mitigate the Interest broadcast storm in VNDN. However, these strategies do not provide any reliable mechanism for Interest and Data forwarding to address the problem of low performance caused by the dynamic and unreliable VANETs communication environment. In this paper, we propose a packet forwarding strategy based on optimal and backup (PFOB) for VNDN. For Interest, PFOB establishes a single-path forwarding with high reliability and reachability by increasing the signal strength and node-degree criterion and retransmission mechanism. For Data, PFOB provides a reliable multi-path backup forwarding mechanism without additional network overhead. Simulation results show that PFOB can effectively improve the Interest satisfaction ratio, reduce the number of application retransmissions, and reduce the Interest satisfaction delay compared to the current strategies.

Vehicular Ad hoc Networks (VANETs) being a vital component of Intelligent Transport System (ITS), is getting due attention from the research community. VANET are self-organized networks, offering a variety of services, comprising not only the safety of drivers and commuters but also provides them travel comfort, while they are on the wheels. But due to some inherent characteristics of VANETs, information dissemination is a big challenge in both dense and sparse environments. Simple broadcasting in the dense traffic environment leads to redundancy of packets, channel access contentions, and packet collisions. This results in a broadcast storm problem. On the contrary, when the traffic density is very low, information dissemination is affected by network partition and network fragmentation. To deal with such issues, we propose a Position Based Speed Adaptive Dissemination (PBSAD) approach, where relay nodes for rebroadcast are selected considering the geographical position of vehicular nodes, irrespective of their direction of movement. The speed of the message sending vehicle is taken into consideration while evaluating the time slots for rebroadcasting nodes. The approach avoids periodic beaconing to gather 1-hop information. Further, this approach ensures information dissemination in a sparse environment as well by using the store, carry, and forwarding concept in which vehicles moving in either direction can act as relay nodes. To validate the proposed approach, a comparative analysis of the PBSAD approach is done with few state of art schemes based on parameters like message delivery ratio, delay, and the number of collisions. The simulation results reveal that PBSAD performs efficiently.

Named Data Network (NDN) has caused wide concerns in VANET community because NDN uses a content-centric mechanism that naming content rather than the host. However, integrating NDN into VANET (NDN-VANET) also faces several challenges including consumer/provider mobile, broadcast storm problem and so on. In this paper, we propose a Bayesian-based Receiver Forwarding Decision (BRFD) scheme to mitigate the broadcast storm problem incurred by interest packets in NDN-VANET. In the BRFD, vehicles received an interest packet are required to make forwarding decisions based on Bayesian decision theory according to current network conditions obtained by neighbor interaction. However, the receiver-forwarding decision in BRFD can also cause a conflict issue because multiple vehicles forward copies of the same packet at the same time. So a back-off mechanism is introduced in BRFD. Experimental results show that the BRFD algorithm has better performance in several aspects in contrast to probability-based forwarding scheme and "bread crumb" routing.

Content retrieval is becoming an emerging application on an integrated network structure referred to as Software Defined Network and Vehicular Ad hoc Network (SDVN). The SDVN is expected to flexibly provide efficient packet routing without deploying road side units. In such the infrastructure-less environment, however, it is challenging to retrieve contents from dynamic networks clustered with vehicles on roadways. As a solution to the problem, we propose a new network design by conjoining Named Data Network (NDN) with SDVN (NDN-SDVN). The new NDN-SDVN is designed as to improve stableness of the cluster formation and hence enables to efficiently perform the content retrieval over Vehicle-to-Vehicle (V2V) communications. Note that one of the most important problems in the V2V is how to select a cluster head. The proposed NDN-SDN adaptively determines the cluster head by using the SDN controller under the maximum Quality of Service (QoS) criterion, while reserving an assistance head based on a Moth Flame Optimization (MFO) algorithm to immediately recompose a new cluster with the back-off time. Moreover, the content retrieval in the NDN-SDVN can be performed over both intra- and inter-cluster communications. To this end, a Kalman filter with Neural Network (KF-NN) is applied for selecting a certain number of preferable vehicles in 1-hop in order to mitigate the broadcast storm problem that often occurs in an NDN. Content retrieval is initiated by sending interest packets including two additional fields of the timestamp and the target MAC address. The head vehicle of the SDN controller maintains ontology regarding the content information cashed by other vehicles, which significantly improves the packet delivery ratio. This NDN-SDVN design is developed on the OMNeT++ simulator and their advantageous results are evaluated in terms of the head lifetime, the cluster lifetime, the satisfactory rate, the latency and the packet delivery ratio.

PurposeAn Improved Rank Criterion-based NLOS node Detection Mechanism (IRC-NLOS-DM) is proposed based on the benefits of a reputation model for effective localization of NLOS nodes during the dynamic exchange of emergency messages in critical situations.Design/methodology/approachThis proposed IRC-NLOS-DM scheme derives the benefits of a reputation model that influentially localizes the NLOS nodes under dynamic exchange of emergency messages. This proposed IRC-NLOS-DM scheme is an attempt to resolve the issues with the routing protocols that aids in warning message delivery of vehicles that are facing NLOS situations with the influence of channel contention and broadcast storm. It is developed for increasing the warning packet delivery rate with minimized overhead, delay and channel utilization.FindingsThe simulation results of the proposed IRC-NLOS-DM scheme confirmed the excellence of the proposed IRC-NLOS-DM over the existing works investigated based on the channel utilization rate, neighborhood prediction rate and emergency message forwarding rate.Practical implicationsIt is proposed for reliable warning message delivery in Vehicular Ad hoc Networks (VANETs) which is referred as the specialized category of mobile ad hoc network application that influences Intelligent Transportation Systems (ITS) and wireless communications. It is proposed for implementing vehicle safety applications for constructing a least cluttered and a secure environment on the road.Originality/valueIt is contributed as a significant mechanism for facilitating reliable dissemination of emergency messages between the vehicular nodes, which is essential in the critical environment to facilitate a risk-free environment. It also aids in creating a reliable environment for accurate localization of Non-Line of Sight (NLOS) nodes that intentionally introduces the issues of broadcasting storm and channel congestion during the process of emergency message exchanges.

A high rate of historical accidents on public roads motivated the advent of the Wireless Access in Vehicular Environment (WAVE) standard. The main objective of WAVE was to develop strategies and protocols to enable inter-vehicular communication in view to reduce accident on public roads. Moreover, a successful message exchange can only be possible if the transmission medium is collision free. Under the Intelligent Transportation System (ITS), the cooperative Awareness messages (CAM) have to be transmitted at the rate of 10 Hz as per standard. To account for congestion management, the Distributed Congestion Control (DCC) mechanism was proposed. However, under higher node density, the DDC becomes inefficient and dramatically contribute to the deterioration of the VANET environment. The present work proposes a Dynamic Broadcast Storm Mitigation Algorithm (DBSMA) which can be used to combat the broadcast storm problem in a Vehicular Network (VN). The DBSMA approach performance was assessed against the DCC approach in twofold, first as a function of variable congestion condition under fixed mobility and secondly in term of variable speed under fixed density congestion. Results from several simulations confirmed that the DBSMA has a potentiality to conquer the effect of broadcast storm by offering higher robustness compared to DCC with about 130% improved efficiency. In addition to its computational simplicity, the DBSMA is easy to implement.

Efficient routing and broadcasting among a set of nodes play a critical role in wireless adhoc networks. for energy efficient routing, a connected dominating set (CDS) based virtual backbone is a promising approach. In the network, one-hop neighbors are selected as multi point relay (MPR) by each node to cover all its two-hop neighbors for the purpose of broadcasting and 2-hop repair. To improve the network lifetime, energy efficient MPR based CDS construction has been proposed by considering the node degree, energy level, node ID and velocity of the node. We also propose a route discovery protocol to relay route request messages, which makes use of the CDS nodes to obtain a stable routing path; 2-hop repair for route maintenance, which reduces the path damage (reduced control packets with lesser consumption of bandwidth) and broadcast storm problem. The simulation results show that the proposed protocol increases the network lifetime up to 30% than other works and effectively repair damaged routes by reducing control packets.

Extensive research attention has been devoted to the Vehicular Sensor Network (VSN) owing to its great potential in environment monitoring. Still, it is difficult to diminish the broadcast storm and data collisions in vehicular senor environment. Due to improper broadcasting of safety message and transmission of packet at same time from multiple vehicles leads to collision. Our key intention is to overwhelm these shortcomings in VSN. Hence, we propose Novel Segment based Safety message broadcasting in Cluster (NSSC) based VSN. Our NSSC is mainly concentrated in three successive processes that are Cluster Formation, Collision Avoidance and Safety Message Broadcasting. Cluster formation is performed originally to sustain stable vehicular environment. Here, Variant based Clustering (VbC) Scheme is proposed to elect Cluster Head (CH) and to form clusters. CH is selected using Chaotic Crow Search (CCS) algorithm. In accord to mitigate the data collision during transmission between CH and Cluster Member, we propose Adaptive Carrier Sense Multiple Access/Collision Avoidance (Ada-CSMA/CA) protocol. Safety message broadcasting adopts Segment based Forwarder Selection (SFS) scheme which selects optimal forwarder using Fuzzy-Vikor method. In this, optimal forwarder is selected concerning to broadcast safety message which reduces the broadcast storm. In regard to validate the proposed NSSC, we have conducted simulations on Omnet++ and SUMO simulator based Veins framework. The acquired results are auspicious in terms of succeeding metrics reachability, average number of collision, duplicate data packets, latency, packet delivery ration and throughput.

Effective information dissemination constitutes the cornerstone of communication in Vehicular Ad hoc Networks (VANETs). Avoiding broadcast storm is one of the considerable challenges in the development of an effective dissemination scheme for VANETs, which leads to extensive rebroadcasting. Reliable emergency messages delivery is another substantial measure of performance, especially in dense traffic and high mobility scenarios. A generic solution to deal with these problems is to cluster vehicles, so that emergency messages can be re-broadcasted to adjacent clusters only by a smaller number of vehicles. Thus, reliable selections of cluster head and relay nodes are important to reduce the number of retransmissions. In this regard, we propose a clustering technique for Reduced Broadcast Overhead Scheme for Emergency Message Dissemination (RBO-EM). RBO-EM is based on the mobility metrics to strengthen the cluster formation, avoid communication overhead and maintain the message reliability in a high mobility scenario. Moreover, we introduce relay nodes based on estimated link stability to limit the number of retransmissions. RBO-EM is evaluated against eminent schemes by varying traffic densities and speed. Simulation results indicate that RBO-EM enables a reasonable performance gain in terms of coverage, end-to-end delay and message reliability.

Since the last decade, the emergence of affordable smart devices in web-connected environments (e.g., smart cities and buildings) has been a critical step towards improving user comfort. In this respect, notifying end-users about different essential events in their environment is of significant interest. Thus, the design of an efficient data dissemination strategy is of paramount importance. The thriving challenge would be to inform interested devices about an event and to avoid as far as possible the network collision problem. To overcome these limitations, we introduce a new generic and adaptive data Dissemination Strategy in Connected Environments (DSCE). Our strategy’s main thrust is reaching a high delivery ratio as well as a low network overhead by sending messages only to the interested devices. To do so, we rely on a semantic-based approach to define device interests and to identify salient messages. Moreover, to cope with the broadcast storm problem and to organize the scheduling of data dissemination, we provide a new waiting time measure for each device before rebroadcasting any received message. The performed experiments show that our strategy outperforms its competitors in terms of effectiveness and efficiency.

The number of vehicles on the roads has increased proportionally over the last couple of years and this number is likely to rise due to the increase in population growth and the number of vehicles that are manufacturing every day. This high traffic density leads to several problems, from which effectively disseminating the emergency messages is a major concern. Keeping in view the dynamic characteristics of VANETs, significant challenges are faced in disseminating the message across the network. The major challenges are the broadcast storm problem, hidden node problem and the packet collision. Many studies have been performed to devise an effective and reliable mechanism for disseminating emergency messages in a Vehicular ad-Hoc Network (VANET). Researchers have proposed different models to tackle various types of scenarios for emergency message dissemination. This paper not only reviews some recent contributions to emergency message dissemination in vehicular networks but also discusses various proposed methods based on Intelligent Transportation System (ITS), Internet of Things (IoT), Priority messaging, Clustering approach, Software Defined Network (SDN) and Fog Computing. We have also tried to explore the latest developments in emergency message dissemination using 5G networks.

Effective data distribution algorithm plays an important role in the Vehicular Ad Hoc Networks (VANETs). However, the broadcast storm often appears when VANET uses broadcast to communicate which means some nodes receive too many packages to deal with. Moreover, the algorithm often becomes inefficient due to the frequency changes in the different network densities. To address these issues, the beacons are used to judge the network state and then the nodes can select the corresponding data distribution mode under different vehicle densities.Simulation results show that the proposed algorithm has better performance in the coverage rate, delivery rate, and packet loss rate than the Flooding and the AID(An adaptive approach for information dissemination).

A flooding algorithm aims to distribute messages to all nodes within the mobile environment. In a simple flooding scheme, every node broadcasts a newly received message. However, this simple mechanism generates massive redundant messages, which is referred to as the broadcast storm problem. To ease the negative effect of the broadcast storm problem, we proposed a novel scheme, Probabilistic Second-chance broadcasting with/without Global positioning system information (PSG) in wireless ad hoc networks, which amalgamates the merits of probability-based and location-based flooding algorithms. PSG eases the broadcast storm problem by reducing the total number of transmissions and does not require hello messages from neighboring nodes, yet achieves better results than Multipoint Relaying Flooding (MPR), a neighbor-knowledge-based flooding scheme, by accurately determining whether subsequent forwarding is advantageous while a node receives a broadcasting message. We also discuss the advantages of a two-phase/second-time algorithm and utilize a simplified topology to further explain and demonstrate the merits of second-time broadcasting. We compare our PSG scheme with the simple flooding scheme, the probabilistic schemes with different pre-assigned probabilities, and the MPR schemes with or without the overhead of hello messages. The simulation results show that our scheme demands fewer forwarding nodes to rebroadcast messages and therefore lowers the total number of transmissions. PSG scales down a large number of collisions and attains high delivery ratios compared to other flooding algorithms.

As on-road vehicles are increasing every year, safety on the road has become one of the major concerns. Therefore, Vehicular Ad Hoc Network (VANET) becomes as an important role on the road. In VANET, communication occurs between vehicles and the infrastructures. During broadcasting, an emergency message is transferred to the surrounding vehicles to alert other vehicles in the area. However, blind flooding in wireless network might result in redundant rebroadcast, contentions and collision with the neighbouring nodes. This situation is named as broadcast storm. Broadcast storm might lead to the losses of the information or lead to the wrong information being transmitted to the neighbouring nodes. The paper aims to design a broadcast control system which is able to optimize the broadcast process in VANET. Vehicular network is modelled in Simulation of Urban Mobility (SUMO) and the algorithm is formulated in MATLAB. Data is extracted from SUMO through Traffic Control Interface for MATLAB (TraCI4Matlab). The broadcast protocol and Particle Swarm Optimization (PSO) algorithm are formulated in this paper. At the same time PSO is modified for the broadcast enhancement. Results showed that after parameters tuning the modified PSO is able to broadcast into a larger coverage area at a faster rate.

Safety message (SM) dissemination in vehicular ad hoc network needs to be fast as it allows vehicles to become alert and avoid adverse situations. An SM usually gets disseminated within a topology by multi-hop broadcast technique. Existing protocols have proposed various controlled flooding mechanisms to address the issues of broadcast storm and network partition. However, no work has been done to take care the direction of message dissemination. In a real scenario, all vehicles within an area of interest (AOI) are not equally affected by an emergency incident. The vehicles of the road where the incident happened, or the vehicles of roads which are connected to incident location by nearby junctions, are most affected and hence are more relevant to receive the SM as fast as possible. Hence, this study proposes a novel method to predict the relevance of vehicles using a distributed algorithm and heuristically tries to disseminate SM toward the relevant vehicles. The authors have compared their work with three state of-the-art algorithms and found that vehicular relevance-based data dissemination is compatible with the existing algorithms on the metrics of packet loss and dissemination delay, but clearly leading in the metric of relevant dissemination.

Conventionally, a node or vehicle in the Named Data Networking (NDN) sends an interest packet to discover information and receives a single data packet in response. However, in the case of named data Vehicular Cyber-Physical System (VCPS), a vehicle may require content from multiple vehicles in the network. Therefore, NDN forwarding daemon must receive multiple data packets in response to a single interest. Moreover, the data broadcast storm worsens in the named data VCPS due to the broadcast nature of the wireless link. In this letter, we propose the data packet broadcast suppression method for any multisource content discovery in VCPS. The proposed scheme distributively selects the potential data forwarding vehicles based on the neighbor distance, node density, and the closeness to the data forwarding line of sight. Our simulation results show that the proposed scheme alleviates 55% data traffic, 17% average per-hop delay, and achieves 7% more data discovery ratio.

Broadcast storm refers to the bandwidth saturation caused by broadcast traffic flows when a loop exists and it can quickly lead to the network failure. In legacy networks, spanning tree protocol (STP) is used to prevent loops in layer 2. This protocol is designed for distributed networks. However, for software defined networks (SDNs) as a new architecture for computer networks, it is necessary to have a new paradigm. In SDN architecture, control plane is decoupled from data plane and implemented centrally so it can be utilized to find a better solution using its global view. In this paper, a new method to prevent loop in SDNs is introduced and evaluated. The proposed method in comparison with STP, has better performance, because of blocking fewer switch ports and utilizing more capacity of the switches. The comprehensive simulation results showed the effectiveness of the proposed method.

In robotics, mechanized and computer simulation for accurate and fast crash detection between general geometric models is a fundamental problem. The explanation of this problem will gravely improve driver safety and traffic efficiency, vehicular ad hoc networks (VANETs) have been employed in many scenarios to provide road safety and for convenient travel of the people. They offer self-organizing decentralized environments to disseminate traffic data, vehicle information and hazardous events. In order to avoid accidents during roadway travels, which are a major burden to the society, the data, such as traffic data, vehicle data and the road condition, play a critical role. VANET is employed for disseminating the data. Still the scalability issues occur when the communication happens under high-traffic regime where the vehicle density is high. The data redundancy and packet collisions may be high which cause broadcast storm problems. Here the traffic regime in the current state is obtained from the speed of the vehicle. Thus the data reduction is obtained. In order to suppress the redundant broadcast D-SAC data, dissemination protocol is presented in this paper. Here the data are classified according to its criticality and the probability is determined. The performance of the D-SAC protocol is verified through conventional methods with simulation.

Internet of Vehicle (IoV) is playing an increasingly important role in constructing an Intelligent Transport System (ITS) of safety, efficiency, and green. Safety applications such as emergency warning and collision avoidance require high reliability and timeliness for data transmission. In order to address the problems of slow response and local broadcast storm commonly existing among waiting-based relay schemes of emergency messages, a local topology information sensing technology-based broadcast (LISCast) protocol is proposed in this paper, making use of the advantage of probability-based forwarding scheme in redundancy inhibition. According to the beacon broadcasted periodically between vehicles, LISCast collects information about number and distribution of neighbor, from which the characteristic information such as effective candidate number, maximum forwarding distance, and global traffic density are extracted. Through embedding the characteristic information into the head of broadcast packets by the message sender for assisting in making relay decision, the alternative receivers uniformly schedule forwarding priorities in a distributed and adaptive way. LISCast works without the help of a roadside unit and generates a little more overhead. The simulation results show that LISCast improves the ability to adapt to dynamic topology by optimizing the performance of delay, redundancy, and broadcast efficiency upon the condition of satisfying the high level of transmission reliability.

Broadcasting in mobile ad hoc networks is performed using various techniques like blind flooding, counter based broadcast, probabilistic broadcast etc. Among these flooding is the most primitive, where every node forwards the broadcast message whenever it gets the message for the first time. However, duplicate copies of the same broadcast message are always eliminated. In spite of simplicity of the mechanism, it results in highly redundant retransmission, contention and collision in the network. This is popularly termed as broadcast storm problem. Probabilistic broadcast method reduces the broadcast probability from 1 to some fraction close to 0.5. Certain probabilistic scheme use fixed probability while some others take into account network size, total number of nodes etc. The proposed article fuzzy controlled probabilistic broadcast or FPR computes rebroadcast probability of a node based on various factors line distance of downlink neighbours of current node from broadcast source, left, right, top, bottom coordinators of nodes already covered, hop count etc. Simulation results reveal that the proposed protocol improves network throughput, saves a lot of rebroadcast while reducing end-to-end delay.

Probabilistic flooding is commonly considered in vehicular ad-hoc networks (VANETs) to alleviate the celebrated broadcast storm problem. Heuristics and simulations have so far proved to be an efficient way with which to design probabilistic information dissemination solutions with demonstrated effectiveness. Supplementing with mathematical analysis for both design and evaluation is expected to generalize the results, and increase the confidence in the proposed solutions. So far, this has been limited due to the difficulties associated with the underlying stochastic dependencies. In this paper, we introduce simple models of single and multiple lane roads to design effective probabilistic flooding schemes for VANETs. The proposed analytical framework offers a novel and generic tool which can cover any number of lanes, vehicle transmission range, and density. We derive difference equations whose solutions yield the probability of all vehicles receiving the emergency warning message as a function of the rebroadcast probability, the number of neighbors of each vehicle, and the dissemination distance. The models are validated using simulations, realistically representing both the traffic and networking aspects, and are used as a baseline to design two schemes for information dissemination which employ probabilistic flooding. The one attempts direct calculation of the required parameters whereas the other adaptively regulates the rebroadcast probability based on the vehicle speed. The schemes are evaluated using simulations and are found to achieve significant performance improvements compared to blind flooding with respect to the achieved reachability, end-to-end delay, and number of rebroadcasts, comparable to the performance achieved by optimal flooding, obtained via brute force. 20 2 556 570

With the advancement in technology and inception of smart vehicles and smart cities, every vehicle can communicate with the other vehicles either directly or through ad-hoc networks. Therefore, such platforms can be utilized to disseminate time-critical information. However, in an ad-hoc situation, information coverage can be restricted in situations, where no relay vehicle is available. Moreover, the critical information must be delivered within a specific period of time; therefore, timely message dissemination is extremely important. The existing data dissemination techniques in VANETs generate a large number of messages through techniques such as broadcast or partial broadcast. Thus, the techniques based on broadcast schemes can cause congestion as all the recipients re-broadcast the message and vehicles receive multiple copies of same messages. Further, re-broadcast can degrade the coverage delivery ratio due to channel congestion. Moreover, the traditional cluster-based approach cannot work efficiently. As clustering schemes add additional delays due to communication with cluster head only. In this paper, we propose a data dissemination technique using a time barrier mechanism to reduce the overhead of messages that can clutter the network. The proposed solution is based on the concept of a super-node to timely disseminate the messages. Moreover, to avoid unnecessary broadcast which can also cause the broadcast storm problem, the time barrier technique is adapted to handle this problem. Thus, only the farthest vehicle rebroadcasts the message which can cover more distance. Therefore, the message can reach the farthest node in less time and thus, improves the coverage and reduces the delay. The proposed scheme is compared with traditional probabilistic approaches. The evaluation section shows the reduction in message overhead, transmission delay, improved coverage, and packet delivery ratio.

Flying ad hoc networks (FANETs) are a new paradigm that can overcome mission constraints of single unmanned aerial vehicles (UAVs). FANETs are composed of several UAVs that cooperate to accomplish some critical mission (i.e., hazardous area monitoring). In order to maintain UAVs coordination, all UAVs must continuously retransmit or relay messages through the wireless channel to assure that every UAV knows the FANET condition. However, when this message exchange is done arbitrarily, it may cause the broadcast storm problem, leading the wireless medium to an inoperable state. Despite some efforts reported in the literature for providing general broadcast storm problem mitigation techniques, the challenge of aggregating new information/knowledge to receivers, instead of just spreading the information in the network, has received less attention. In this paper, we not only prove that broadcast storm problem causes network contention as the number of UAVs increases but also propose the innovative dynamic neighborhood-based algorithm for the broadcast storm problem (DNA-BSP), which was developed and validated based on the outdoor experiments and computer simulations. It can mitigate the broadcast storm problem, which is a real challenge in FANETs, reducing message redundancy in more than 98%, and making message delivery more than 95% faster than in flooding scenario, outperforming classical broadcast storm mitigation techniques when applied in FANETs. Our detailed results can also guide future researches and provide useful insights for engineers planning and optimizing mission-critical mobile ad hoc network with the support of UAVs.

In unstructured mobile peer-to-peer systems (MP2P), the frequent link breakages lead frequent topology mismatching problems and data transmission failures due to high mobility of nodes. The overhead of data transmission and synchronization cannot be neglected. In order to keep the data consistent, flooding is a fundamental and straightforward data synchronization mechanism since a mobile node does not know which else has the same shared data item. However, data flooding causes the broadcast storm problem. In this paper, we propose a mobility-aware data update approach (MADU) to improve the data dissemination and to reduce the overhead of maintaining the consistency of shared data items in an MP2P network. We use safe-time which is derived from the neighbor’s location and speed to determine the time for a node to do the checking and updating between the neighbor nodes and itself. We also consider the network connectivity of a mobile node and access frequency of a data item as the factors to trigger the update process. By combining the mobility information of nodes, network connectivity, and access frequency of data items, we set a reasonable data update mechanism, which can significantly decrease the number of retransmissions and redundant messages so as to reduce the overhead of maintaining the data consistency.

Recently, Vehicular Ad hoc Networks (VANETs) is focused on by many researchers. VANET’s specific characteristics like high-speed, unstable communication link, network partitioning, and information transfer become a hard challenging problem. Access control depends on IEEE 802.11p and has been used for Vehicle to Everything (V2X) and Vehicle to Vehicle (V2V) communications. The high dynamics of VANET nodes which will cause frequent disconnection of links and even partitioning of networks causes the source vehicle is lost their message of data that disseminated to the destination region, and also may lead to the message redundancy, causing a broadcast storm. One of the suggested solutions for this in VANET is the clusters. This paper will focus on the dissemination of cluster-based data. The clustering algorithm is provided according to the highway road, the proposed algorithm seeks to increase the network stability by identifying the Cluster Head (CH) periodically. By using a suggested variable range of cluster head (R-of-CH) in this paper to be a measure of finding the CH for each new vehicle. The simulation results are performed by NetLogo, under different vehicle densities and different values of (R-of-CH). The results of the simulation show the proposed algorithm contributes to making the network more stable with a high delivery rate as the disseminated messages will reach all vehicles in the simulated area. It indicates that the coverage rate is also high and the lost message rate is very low.

In this paper, we target dissemination issues of emergency messages in a highly dynamic Internet of Vehicles (IoV) network. IoV is emerging as a new class of vehicular networks to optimize road safety as well as users’ comfort. In such a context, forwarding emergency messages through vehicle-to-vehicle communications (V2V) plays a vital role in enabling road safety-related applications. For instance, when an accident occurs, forwarding such information in real time will help to avoid other accidents in addition to avoiding congestion of network traffic. Thus, dissemination of emergency information is a major concern. However, on the one hand, vehicle density has increased in the last decade which may lead to several issues including message collisions, broadcast storm, and the problem of hidden nodes. On the other hand, high mobility of vehicles and hence dynamic changes of network topology result in failure of dissemination of emergency packets. To overcome these problems, we propose a new dissemination scheme of emergency packets by vehicles equipped with both DSRC and cellular LTE wireless communication capabilities. Our scheme is based on a dynamic clustering strategy, which includes a new cluster head selection algorithm to deal with the broadcast storm problem. Furthermore, our selection algorithm enables not only the election of the most stable vehicles as cluster heads, and hence their exploitation in forwarding the emergency information, but also the avoidance of packet collisions. We simulated our scheme in an urban environment and compared it with other data dissemination schemes. Obtained results show the efficiency of our scheme in minimizing collision and broadcast storm problems, while improving latency, packet delivery ratio and data throughput, as compared to other schemes.

In Vehicular Adhoc Networks (VANETs), disseminating Emergency Messages (EMs) to a maximum number of vehicles with low latency and low packet loss is critical for road safety. However, avoiding the broadcast storm and dealing with large-scale dissemination of EMs in urban VANETs, particularly at intersections, are the challenging tasks. The problems become even more challenging in a dense network. We propose an Effective Emergency Message Dissemination Scheme (EEMDS) for urban VANETs. The scheme is based on our mobility metrics to avoid communication overhead and to maintain a stable cluster structure. Every vehicle takes into account its direction angle and path loss factor for selecting a suitable cluster head. Moreover, we introduce estimated link stability to choose a suitable relay vehicle that reduces the number of rebroadcasts and communication congestion in the network. Simulation results show that EEMDS provides an acceptable end-to-end delay, information coverage, and packet delivery ratio compared to the eminent EM dissemination schemes.

Recently, many researches on Vehicular Ad Hoc Networks (VANETs) have been performed because of the many related applications. Data dissemination is among the challenging issues face by these kinds of networks to overcome several problems, such as broadcast storm, and network fragmentation. In this respect, the present work proposes a new Geocast-based Safety Information Dissemination protocol for VANETs, called Geo-SID. The proposed protocol is used for dissemination of safety information in a V2V scenario. It is specifically designed and suitable for an urban environment. The main goal of Geo-SID scheme is to perform the safety information dissemination process within a Zone of Relevance (ZoR) and without using the Zone of Forwarding (ZoF) similar to existing dissemination protocols in the literature. Furthermore, our solution aims to eliminate the broadcast storm problem by avoiding irrelevant alert messages and providing an efficient safety data dissemination across a ZoR area by extending the coverage area, reducing the network overhead and improving the latency. We simulate our proposed protocol using network simulator NS-3 and SUMO environment. Our proposed protocol outperforms similar protocols available in the literature based on the obtained simulation results.

International audience; In recent years, the decentralized wireless Vehicular Ad hoc Networks (VANETs) have emerged as a key technology for Intelligent Transportation Systems (ITS). The need for an efficient and reliable broadcast protocol, mainly in urban VANETs, is of great importance to support different services such as road safety, traffic efficiency, entertainment and advertisement. This paper proposes two new routing broadcast protocols: the Enhanced Counter-based broadcast protocol in Urban VANET (ECUV) and the Enhanced distance-based broadcast protocol in Urban VANET (EDUV). Both of them improve the distribution of data on urban VANETs. ECUV and EDUV use a road-network-topology-based approach to select a set of relay nodes with enhanced coverage capabilities during the data delivery in urban Vehicle to Vehicle (V2V) scenarios. They also improve the performance of the receiver-based protocols by alleviating the negative effect of their stochastic behavior. We study the behavior of these protocols with an analytical model, which shows that the enhanced versions reduce the transmission probability in high vehicle density to avoid the broadcast storm problem. Moreover, the obtained results proved that these proposed protocols increase the transmission probability in low vehicle density to satisfy the reachability requirement of data broadcasting. The network simulation results show clearly that ECUV and EDUV outperform other methods in terms of coverage capacity and efficiency.

The rapid growth of global car ownership leads to energy shortage, environmental pollution, traffic congestion and frequent accidents. The development of intelligent connected vehicle is an effective way to solve the above problems, and it is also the future development direction of automobile. One of the key problems of intelligent network connection of automobile is how to build VANET. In the case of a large number of vehicles gathering, the frequent and intensive interaction of massive communication participants in VANET will inevitably produce broadcast storm, which will lead to network paralysis. To solve the above problems, in this paper, a periodically transmitted rpcm broadcast message forwarding control strategy was designed, and the effect of the forwarding control strategy was analyzed in three scenarios of intersection meeting, multi hop chain meeting and multi vehicle congestion. Simulation results show that the forwarding control strategy can greatly reduce the number of broadcast data packets and improve the effective throughput in large-scale VANET. Moreover, the wider the bandwidth, the higher the throughput performance. When forwarding packets to 32 nodes in 5 m bandwidth, the throughput performance is improved by more than 60%. It has obvious effect on suppressing broadcast storm.

In order to ensure reliable data transmission of sender, the tree-based network is extended to Mesh network by collaborative technology, and the SW-HBH-CARQ broadcast scheme is introduced for the first time. Then, in order to solve the problems of broadcast storm and energy saving, SW-HBH-oiCARQ, SW-HBH-ieCARQ, and SW-HBH-oieCARQ are further proposed. Then, the four broadcasting schemes are analyzed quantitatively, and the performance indicators such as system energy consumption and time delay are obtained. Finally, the relationships between the performance indexes and the parameters are discussed by numerical simulation. At the same time, the effectiveness of the proposed schemes in energy saving is verified by comparing with the corresponding noncollaborative broadcasting scheme. However, the latency of proposes scheme is greater than uncooperative scheme, which is the cost of saving energy and resolving broadcast storms.

Efficient Data dissemination in VANET is still the challenge because of variable speed of vehicles, road conditions, frequent fragmentation etc. In this article a selective forwarding data dissemination scheme using exit time differences in vehicles for highway lanes scenario is proposed that focuses on the solution of broadcast storm, less coverage, transmission delay and reliable data delivery. Our approach is selecting multiple forwarding nodes to increase coverage in less delay. In this article road lanes concept is used to identify the moving node direction. Redundant regions and zones technique in proposed approach is reducing the processing of parameters at significant extents. Simulation of proposed approach is done using NS2 and SUMO. Output of implementation is compared with unidirectional flooding, KB_Selective, and LT_Selective techniques. Result analysis shown that the proposed technique is much efficient and it increases the rate of coverage up to 23%. Also it reduces the delay up to 18% in data delivery ratio. This methodology also improves the performance of system by increasing the throughput and reducing the collision rate in comparison with other methods.

Mobile ad hoc network (MANET) is a group of wireless mobile nodes that create a temporary network without the help of any central administration or standard support services. Mobility of nodes determines the overall performance of MANET networks. High mobility of nodes causes frequent changes in the network topology, and this leads to link breakage and increases reinitiating of the route discovery process. MANETs commonly use broadcasting techniques for route discovery process. However, it can cause redundant rebroadcasts, packet collisions, and channel contention. The main objective of this paper is to design and develop the mobility-aware routing algorithm (MARA) to enhance the performance of the routing protocol in MANETs. The proposed scheme allows mobile nodes to rebroadcast or discard received broadcasted messages. The decision is based on the combination of node speed, distance between nodes, and residual energy of nodes. These parameters are considered both in route request and route reply process to reduce the chance of link breakage and broadcast storm problems. The proposed algorithm has been evaluated based on the performance metrics: packet delivery ratio, average end-to-end delay, throughput, and routing overhead. We have used network simulator NS-2 V-2.35. The simulation results revealed that MARA outperforms ad hoc on-demand distance vector (AODV), mobility and direction aware (MAD), and mobility and energy-aware (MAE) routing protocols.

Broadcast storm created during the message exchanges in MANET is a serious issue in routing as MANET nodes have limited processing resource and residual energy. Researches in the area of connected dominating set (CDS) in MANETs mostly focus on centralized approaches, which require strong and stable topological information about the MANET. Adaptation of centralized algorithms is intangible due to the dynamic nature of the MANET and will demand extensive control message exchange. Hence, it is required to deduce an algorithm to compute CDS using the partial observations of the MANET. In this paper, a Q learning-based CDS formation algorithm has been proposed with extended episodic length approach for efficient MANET routing. In the proposed algorithm, the CDS nodes were chosen not only based on its own Q value but also based on the Q value of its neighbours. In this way, the episodic length of the Q learning algorithm is extended from one hop to two hops. Here residual energy and signal stability are used to estimate the Q values of the individual nodes. The simulation of the algorithm gives promising results when compared to conventional CDS establishment algorithms.

Named data networking (NDN) is promising for Vehicular Ad hoc Networks (VANETs) owing to its data-centric communication paradigm. However, the existing forwarding strategies for vehicular named data networks (VNDN) cannot handle well the issues of high mobility and broadcast storm. In this paper, we propose a Mobility-Predict-based Forwarding Strategy (MPFS) to tackle these issues in VNDN. First, in order to solve the problem of outdated mobility information in the neighbor table, a lightweight but highly effective approach is proposed to predict the current position in MPFS. Then, the predicted mobility information of the vehicles in the neighbor table is applied to select the next-hop forwarder(s) in both directions (road direction and reverse road direction) of the consumer. Furthermore, the vehicle that is farthest from the current forwarder with a stable link is considered as the next-hop forwarder. Finally, extensive simulations are carried out to demonstrate that MPFS has a less number of Interest packets forwarded, while maintaining a higher ratio of satisfied Interest packets compared with the baseline forwarding strategies.

Vehicular Ad Hoc Networks (VANETs) are a variation of mobile ad hoc networks (MANETs) subject to node mobility at high speeds and aiming at providing quick dissemination of safety messages. Thus, since VANETs deal with delivering critical messages communication reliability is paramount. One of the most reliable methods for disseminating messages is flooding. However, the technique is not perfect due to the broadcast storm problem. Clustering can contain this problem by electing cluster masters (CMs) to be responsible for broadcasting only to vehicles inside their clusters. However, communication between CMs become necessary. Since the delays incurred can affect the efficiency of dissemination, merging clusters might be required to reach a tradeoff between solving the broadcast storm problem and adding latency to the dissemination. Therefore, we propose a cluster merging algorithm and measure its effectiveness on a roadside scenario. Simulation results are presented showing the effects on dissemination in VANETs.

In order to further improve the reliability of broadcasting and suppress broadcast storm in Vehicular Ad Hoc Networks, a Real-time Successful Broadcasting Ratio and Distance Based Broadcast (RSBDB) algorithm is proposed. The algorithm dynamically calculates the forwarding probability of a node based on the real-time successful broadcasting ratio of the current node and the distance between the current node and the previous node. A node with higher real-time successful broadcasting ratio and longer distance has larger forwarding probability. Meanwhile, RSBDB also adopts mechanisms such as deferring a random time before transmitting and piggybacking neighbor information in data packets to further suppress broadcast storm and improve broadcast reliability. Simulation results show that RSBDB performs well in suppressing broadcast storm and improving the broadcast reliability.

A flying ad hoc network (FANET) is a mobile ad hoc network (MANET) which comprises a group of flying nodes, unmanned aerial vehicle (UAVs), that communicate with each other. These networks are mainly used in emergency scenarios due to easy deployment and operation. In these networks, the method used to transmit packets is known as flooding. This method makes the nodes retransmit the received packet to all neighbors’ nodes, causing three issues in the network: redundant retransmissions, contentions, and collisions. These issues constitute the broadcast storm problem (BSP) which causes increased latency, packet loss, and unnecessary power consumption by the nodes. Some basic packet retransmission schemes have been proposed to mitigate these drawbacks such as applying probabilistic retransmissions, packet counter and distance between the sending and receiving node. Based on these techniques, hybrid algorithms have been analyzed to improve the network efficiency. The present work studies the performance of hybrid packet retransmission algorithms to reduce the BSP problem in FANET networks by comparing with the traditional operation. The results show the improvement of reachability, the reduction of retransmissions, and the lowering of power consumption.

Vehicular Ad hoc Networks (VANETs) generally comprises vehicular nodes that communicate with one another mostly without utilizing any infrastructure. Multiple applications of VANETs needs to deliver information to the regions of interest and broadcasting is an efficacious communication paragon to rely upon. A simple broadcast suffers from redundancy, high resource utilization, and a number of collisions resulting in the broadcast storm problem. The current network situation depending upon the flow of traffic plays a decisive role where in dense scenarios the number of rebroadcasts should be minimum to avoid redundancy, contention and collisions and in a sparse environment, the number of rebroadcast should be high to improve the reachability of information. We propose an infrastructure-less Optimized Speed Adaptive Beacon Broadcast (OSABB) approach that calculates the information forwarding probability on the basis of the number of vehicular nodes in the vicinity. Simulations are done for OSABB and results are compared with two state-of-the-art existing approaches.

The number of connected cars and the massive consumption of digital content on the Internet have increased daily. However, the high mobility of the vehicles, coming from patterns&rsquo, variation over time, makes efficient large-scale content distribution quite challenging. In light of this, the emerging Vehicular Named Data Network (VNDN) architecture provides support for content-centric network communications and caching capabilities, which allows reliable and larger-scale content delivery over Vehicular Ad-Hoc Networks (VANETs). This notwithstanding, the high number of interest packets in VNDN tends to introduce broadcast storm occurrences during the cache discovery process. Thus, network performance degradation comes up for the influence of both increased packet loss rates and delays on content recovery during communication between vehicles. This work proposes a new cache discOVEry pRoTocol (OVERT VNDN), which combines the computational geometry and degree centrality concepts to tackle the VNDN performance degradation challenges and issues. The main idea behind OVERT VNDN is to choose the most appropriate relay vehicles to engage interest packets&rsquo, delivery within the VNDN, seeking to achieve higher network performance by optimizing broadcast storm incidence. The obtained results suggest that OVERT VNDN outperforms its competitor in the following key performance indicators: (i) improving the cache discovery process by 120.47%, (ii) enhancing the content delivery rate by 43%, and (iii) reducing the number of interest packets by 80.99%.