Models and Performance of VANET based Emergency Braking

The network research community is working in the field of automotive to provide VANET based safety applications to reduce the number of accidents, deaths, injuries and loss of money. Several approaches are proposed and investigated in VANET literature, but in a completely network-oriented fashion. Most of them do not take into account application requirements and no one considers the dynamics of the vehicles. Moreover, message repropagation schemes are widely proposed without investigating their benefits and using very complicated approaches. This technical report, which is derived from the Master Thesis of Michele Segata, focuses on the Emergency Electronic Brake Lights (EEBL) safety application, meant to send warning messages in the case of an emergency brake, in particular performing a joint analysis of network requirements and provided application level benefits. The EEBL application is integrated within a Collaborative Adaptive Cruise Control (CACC) which uses network-provided information to automatically brake the car if the driver does not react to the warning. Moreover, an information aggregation scheme is proposed to analyze the benefits of repropagation together with the consequent increase of network load. This protocol is compared to a protocol without repropagation and to a rebroadcast protocol found in the literature (namely the weighted p-persistent rebroadcast). The scenario is a highway stretch in which a platoon of vehicles brake down to a complete stop. Simulations are performed using the NS_3 network simulation in which two mobility models have been embedded. The first one, which is called Intelligent Driver Model (IDM) emulates the behavior of a driver trying to reach a desired speed and braking when approaching vehicles in front. The second one (Minimizing Overall Braking Induced by Lane change (MOBIL)), instead, decides when a vehicle has to change lane in order to perform an overtake or optimize its path. The original simulator has been modified by - introducing real physical limits to naturally reproduce real crashes; - implementing a CACC; - implementing the driver reaction when a warning is received; - implementing different network protocols. The tests are performed in different situations, such as different number of lanes (one to five), different average speeds, different network protocols and different market penetration rates and they show that: - the adoption of this technology considerably decreases car accidents since the overall average maximum deceleration is reduced; - network load depends on application-level details, such as the implementation of the CACC; - VANET safety application can improve safety even with a partial market penetration rate; - message repropagation is important to reduce the risk of accidents when not all vehicles are equipped; - benefits are gained not only by equipped vehicles but also by unequipped ones

Towards video streaming in IoT environments: vehicular communication perspective

Multimedia oriented Internet of Things (IoT) enables pervasive and real-time communication of video, audio and image data among devices in an immediate surroundings. Today's vehicles have the capability of supporting real time multimedia acquisition. Vehicles with high illuminating infrared cameras and customized sensors can communicate with other on-road devices using dedicated short-range communication (DSRC) and 5G enabled communication technologies. Real time incidence of both urban and highway vehicular traffic environment can be captured and transmitted using vehicle-to-vehicle and vehicle-to-infrastructure communication modes. Video streaming in vehicular IoT (VSV-IoT) environments is in growing stage with several challenges that need to be addressed ranging from limited resources in IoT devices, intermittent connection in vehicular networks, heterogeneous devices, dynamism and scalability in video encoding, bandwidth underutilization in video delivery, and attaining application-precise quality of service in video streaming. In this context, this paper presents a comprehensive review on video streaming in IoT environments focusing on vehicular communication perspective. Specifically, significance of video streaming in vehicular IoT environments is highlighted focusing on integration of vehicular communication with 5G enabled IoT technologies, and smart city oriented application areas for VSV-IoT. A taxonomy is presented for the classification of related literature on video streaming in vehicular network environments. Following the taxonomy, critical review of literature is performed focusing on major functional model, strengths and weaknesses. Metrics for video streaming in vehicular IoT environments are derived and comparatively analyzed in terms of their usage and evaluation capabilities. Open research challenges in VSV-IoT are identified as future directions of research in the area. The survey would benefit both IoT and vehicle industry practitioners and researchers, in terms of augmenting understanding of vehicular video streaming and its IoT related trends and issues

Efficient medium access control protocol for vehicular ad-hoc networks

Intelligent transportation systems (ITS) have enjoyed a tremendous growth in the last decade and the advancement in communication technologies has played a big role behind the success of ITS. Inter-vehicle communication (IVC) is a critical requirement for ITS and due to the nature of communication, vehicular ad-hoc network technology (VANET) is the most suitable communication technology for inter-vehicle communications. In Practice, however, VANET poses some extreme challenges including dropping out of connections as the moving vehicle moves out of the coverage range, joining of new nodes moving at high speeds, dynamic change in topology and connectivity, time variability of signal strength, throughput and time delay. One of the most challenging issues facing vehicular networks lies in the design of efficient resource management schemes, due to the mobile nature of nodes, delay constraints for safety applications and interference. The main application of VANET in ITS lies in the exchange of safety messages between nodes. Moreover, as the wireless access in vehicular environment (WAVE) moves closer to reality, management of these networks is of increasing concern for ITS designers and other stakeholder groups. As such, management of resources plays a significant role in VANET and ITS. For resource management in VANET, a medium access control protocol is used, which makes sure that limited resources are distributed efficiently. In this thesis, an efficient Multichannel Cognitive MAC (MCM) is developed, which assesses the quality of channel prior to transmission. MCM employs dynamic channel allocation and negotiation algorithms to achieve a significant improvement in channel utilisation, system reliability, and delay constraints while simultaneously addressing Quality of Service. Moreover, modified access priority parameters and safety message acknowledgments will be used to improve the reliability of safety messages. The proposed protocols are implemented using network simulation tools. Extensive experiments demonstrated a faster and more efficient reception of safety messages compared to existing VANET technologies. Finally, improvements in delay and packet delivery ratios are presented

Smart handoff technique for internet of vehicles communication using dynamic edge-backup node

© 2020 The Authors. Published by MDPI. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.3390/electronics9030524A vehicular adhoc network (VANET) recently emerged in the the Internet of Vehicles (IoV); it involves the computational processing of moving vehicles. Nowadays, IoV has turned into an interesting field of research as vehicles can be equipped with processors, sensors, and communication devices. IoV gives rise to handoff, which involves changing the connection points during the online communication session. This presents a major challenge for which many standardized solutions are recommended. Although there are various proposed techniques and methods to support seamless handover procedure in IoV, there are still some open research issues, such as unavoidable packet loss rate and latency. On the other hand, the emerged concept of edge mobile computing has gained crucial attention by researchers that could help in reducing computational complexities and decreasing communication delay. Hence, this paper specifically studies the handoff challenges in cluster based handoff using new concept of dynamic edge-backup node. The outcomes are evaluated and contrasted with the network mobility method, our proposed technique, and other cluster-based technologies. The results show that coherence in communication during the handoff method can be upgraded, enhanced, and improved utilizing the proposed technique.Published onlin

Emulation platform design for multimedia applications over vehicular networks

Safety applications seems that will be decisive for a successful introduction to the automotive market for the vehicular networks. However, another kind of applications could be very helpful in order to reach the maximum number of equipped vehicles after market introduction, because can attract a greater number of users and facilitate a vehicular infrastructure investment because vehicular communication must provide business opportunities for Internet service providers to generate revenue. One of these kind of applications is live video streaming over vehicular networks. Video streaming is an attractive feature to many applications, such as emergency live video transmission, video on demand services, road-side video advertisement broadcasting and inter-vehicle video conversation. Test and evaluate implementations in a real testbed environment could be very costly and di cult in this kind of networks. Simulations are still commonly used as a first step in any development for vehicular networks research. Therefore, to test this kind of applications an emulation platform for multimedia applications over vehicular networks is presented in this article. We’ve studied the performance of video streaming services in a infrastructure environment over a highways taking special account in the losses that produces handovers during the communication caused by the network mobility

Emulation platform design for multimedia applications over vehicular networks

Safety applications seems that will be decisive for a successful introduction to the automotive market for the vehicular networks. However, another kind of applications could be very helpful in order to reach the maximum number of equipped vehicles after market introduction, because can attract a greater number of users and facilitate a vehicular infrastructure investment because vehicular communication must provide business opportunities for Internet service providers to generate revenue. One of these kind of applications is live video streaming over vehicular networks. Video streaming is an attractive feature to many applications, such as emergency live video transmission, video on demand services, road-side video advertisement broadcasting and inter-vehicle video conversation. Test and evaluate implementations in a real testbed environment could be very costly and di cult in this kind of networks. Simulations are still commonly used as a first step in any development for vehicular networks research. Therefore, to test this kind of applications an emulation platform for multimedia applications over vehicular networks is presented in this article. We’ve studied the performance of video streaming services in a infrastructure environment over a highways taking special account in the losses that produces handovers during the communication caused by the network mobility

Safety Applications and Measurement Tools for Connected Vehicles

L'abstract è presente nell'allegato / the abstract is in the attachmen

Study of Obstacle effect on the GPSR protocol and a Novel Intelligent Greedy Routing protocol for VANETs

In recent years, connected vehicle technologies have been developed by automotive companies, academia, and researchers as part of Intelligent Transportation Systems (ITS). This group of stakeholders continue to work on these technologies to make them as reliable and cost-effective as possible. This attention is because of the increasing connected vehicles safety-related, entertainment, and traffic management applications, which have the potential to decrease the number of road accidents, save fuel and time for millions of daily commuters worldwide. Vehicular Ad-Hoc Network (VANET), which is a subgroup of Mobile Ad-Hoc Network (MANET), is being developed and implemented in vehicles as the critical structure for connected vehicles applications. VANET provides a promising concept to reduce the number of fatalities caused by road accidents, to improve traffic efficiency, and to provide infotainment. To support the increasing number of safety-related applications, VANETs are required to perform reliably. Since VANETs promise numerous safety applications requiring time-bound delivery of data packets, it is also necessary to replicate real-world scenarios in simulations as accurately as possible. Taking into account the effect of realistic obstacles while simulating a variety of case scenarios increases the reliability of the tested routing protocol to appropriately perform in real-world situations. It also exposes routing protocols to possible vulnerabilities caused by obstacles. Nevertheless, it is not uncommon for researchers to omit real-world physical layer communication hurdles in simulation-based tests, including not considering the effect of obstacles on their routing protocol performance evaluation simulations. Consequently, the performance of these protocols is usually overestimated and do not support in real-world environment. Failure to account for obstacle effects overstate the network performance. In this thesis, a framework for measuring obstacle effects on routing protocols is defined. We also propose, a new routing protocol based on the traditional Greedy Perimeter Stateless Routing (GPSR) protocol called Intelligent Greedy Routing (IGR) protocol. The proposed IGR protocol considers a parameter called $Receptivity$ to chose the next hop in a route. We implemented the new protocol using the Simulation of Urban Mobility (SUMO) and the Network Simulator (NS-3). An analysis of Packet Delivery Ratio (PDR), End-to-End Delay (E2ED) and Mean Hop count with the assumption that nodes (vehicles) are moving in various topologies is presented in this thesis. The study presented here gives a general idea of the effects of obstacles on the Greedy Perimeter Stateless Routing (GPSR) protocol considering multiple realistic scenarios such as Urban, Residential and Highway. In addition, we compare the performance of GPSR and the new IGR protocols with the presence of obstacles considering various topologies. The new proposed IGR protocol performs better compared to the traditional GPSR for all the investigated metrics