2,359 research outputs found

    Requirement analysis for building practical accident warning systems based on vehicular ad-hoc networks

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    An Accident Warning System (AWS) is a safety application that provides collision avoidance notifications for next generation vehicles whilst Vehicular Ad-hoc Networks (VANETs) provide the communication functionality to exchange these notifi- cations. Despite much previous research, there is little agreement on the requirements for accident warning systems. In order to build a practical warning system, it is important to ascertain the system requirements, information to be exchanged, and protocols needed for communication between vehicles. This paper presents a practical model of an accident warning system by stipulating the requirements in a realistic manner and thoroughly reviewing previous proposals with a view to identify gaps in this area

    Improved Road Segment-Based Geographical Routing Protocol for Vehicular Ad-hoc Networks

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    This research was funded by Bahria University, Islamabad Campus.Qureshi, KN.; Ul Islam, F.; Kaiwartya, O.; Kumar, A.; Lloret, J. (2020). Improved Road Segment-Based Geographical Routing Protocol for Vehicular Ad-hoc Networks. Electronics. 9(8):1-20. https://doi.org/10.3390/electronics9081248S1209

    Design and analysis of a beacon-less routing protocol for large volume content dissemination in vehicular ad hoc networks

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    Largevolumecontentdisseminationispursuedbythegrowingnumberofhighquality applications for Vehicular Ad hoc NETworks(VANETs), e.g., the live road surveillance service and the video-based overtaking assistant service. For the highly dynamical vehicular network topology, beacon-less routing protocols have been proven to be efficient in achieving a balance between the system performance and the control overhead. However, to the authors’ best knowledge, the routing design for large volume content has not been well considered in the previous work, which will introduce new challenges, e.g., the enhanced connectivity requirement for a radio link. In this paper, a link Lifetime-aware Beacon-less Routing Protocol (LBRP) is designed for large volume content delivery in VANETs. Each vehicle makes the forwarding decision based on the message header information and its current state, including the speed and position information. A semi-Markov process analytical model is proposed to evaluate the expected delay in constructing one routing path for LBRP. Simulations show that the proposed LBRP scheme outperforms the traditional dissemination protocols in providing a low end-to-end delay. The analytical model is shown to exhibit a good match on the delay estimation with Monte Carlo simulations, as well

    Recent Multicast Routing Protocols in VANET: Classification and Comparison

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    الشبكة المخصصة للسيارات (VANET) صنفت باعتبارها واحدة من أهم فئات شبكات الجيل التالي التي طورت في السنوات الأخيرة بسرعة بالنسبة للمركبات وعمليات نقل الطرق. هذه الشبكه يمكن أن تساعد في تنفيذ مجموعة كبيرة من التطبيقات المتعلقة بالمركبات، اشارة المرور، ازدحام المرور، السائقين، الركاب، الإسعاف، الشرطة، سيارات الإطفاء وحتى المشاة. التوجيه هو المشكلة الأبرز في نقل المعلومات في الـ VANET وهناك العديد من وسائط النشر: البث الاحادي، البث المتعدد و البحث في منطقه جغرافيه معينه (geocast). في هذه المقاله سوف نركز فقط على الإرسال المتعدد الذي يشير إلى عملية إرسال معلومات من عقدة واحدة (تسمى المركبة المصدر) إلى مجموعة من العقد الموجودة في مواقع مختلفة (تسمى المركبات الهدف). والغرض من هذه المقالة هو دراسة بروتوكولات توجيه الإرسال المتعدد الموجودة في الـ VANET وإنتاج دراسه جيد عنها وتحديد مزايا وعيوب كل منها وكذلك تصنيفها إلى فئات مختلفة استنادا إلى بعض العوامل المؤثرة مثل نوعية الخدمة، مسار المركبة وما إلى ذلك. وبعد تحليل بروتوكولات التوجيه هذه وجدنا أن هناك حاجة ملحة لإنتاج بروتوكول توجيه متعدد الإرسال فعال لهذه الشبكة لتقليل استهلاك الموارد وتحسين الأداء العام.Vehicular Ad Hoc Network (VANET) classified as one of the most important classes of next generation networks that developed in recent years rapidly for vehicles and road transmissions. It can help in implementing a large set of applications related to vehicles, traffic light, traffic jam, drivers, passengers, ambulance, police, fire trucks and even pedestrians. Routing is the most prominent problem in the transmission of information in VANETs and there are many modes of dissemination: unicast, broadcast, multicast and geocast. In this paper, we will focus only on the multicast that is referring to a process of sending information from one node (called source vehicle) to a group of nodes that found in different locations (called destination vehicles). The purpose of this paper is to study the existing multicast routing protocols in VANET and produce good survey about them and determine the advantages and disadvantages of each one as well as classify them into different categories based on some effected parameters such as quality of service, vehicle trajectory and etc. After analyzing these routing protocols we concluded that there is persistent need to produce efficient multicast routing protocol in this network to decrease the resource consumption and improve the overall performance

    SNAP : A Software-Defined & Named-Data Oriented Publish-Subscribe Framework for Emerging Wireless Application Systems

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    The evolution of Cyber-Physical Systems (CPSs) has given rise to an emergent class of CPSs defined by ad-hoc wireless connectivity, mobility, and resource constraints in computation, memory, communications, and battery power. These systems are expected to fulfill essential roles in critical infrastructure sectors. Vehicular Ad-Hoc Network (VANET) and a swarm of Unmanned Aerial Vehicles (UAV swarm) are examples of such systems. The significant utility of these systems, coupled with their economic viability, is a crucial indicator of their anticipated growth in the future. Typically, the tasks assigned to these systems have strict Quality-of-Service (QoS) requirements and require sensing, perception, and analysis of a substantial amount of data. To fulfill these QoS requirements, the system requires network connectivity, data dissemination, and data analysis methods that can operate well within a system\u27s limitations. Traditional Internet protocols and methods for network connectivity and data dissemination are typically designed for well-engineering cyber systems and do not comprehensively support this new breed of emerging systems. The imminent growth of these CPSs presents an opportunity to develop broadly applicable methods that can meet the stated system requirements for a diverse range of systems and integrate these systems with the Internet. These methods could potentially be standardized to achieve interoperability among various systems of the future. This work presents a solution that can fulfill the communication and data dissemination requirements of a broad class of emergent CPSs. The two main contributions of this work are the Application System (APPSYS) system abstraction, and a complementary communications framework called the Software-Defined NAmed-data enabled Publish-Subscribe (SNAP) communication framework. An APPSYS is a new breed of Internet application representing the mobile and resource-constrained CPSs supporting data-intensive and QoS-sensitive safety-critical tasks, referred to as the APPSYS\u27s mission. The functioning of the APPSYS is closely aligned with the needs of the mission. The standard APPSYS architecture is distributed and partitions the system into multiple clusters where each cluster is a hierarchical sub-network. The SNAP communication framework within the APPSYS utilized principles of Information-Centric Networking (ICN) through the publish-subscribe communication paradigm. It further extends the role of brokers within the publish-subscribe paradigm to create a distributed software-defined control plane. The SNAP framework leverages the APPSYS design characteristics to provide flexible and robust communication and dynamic and distributed control-plane decision-making that successfully allows the APPSYS to meet the communication requirements of data-oriented and QoS-sensitive missions. In this work, we present the design, implementation, and performance evaluation of an APPSYS through an exemplar UAV swarm APPSYS. We evaluate the benefits offered by the APPSYS design and the SNAP communication framework in meeting the dynamically changed requirements of a data-intensive and QoS-sensitive Coordinated Search and Tracking (CSAT) mission operating in a UAV swarm APPSYS on the battlefield. Results from the performance evaluation demonstrate that the UAV swarm APPSYS successfully monitors and mitigates network impairment impacting a mission\u27s QoS to support the mission\u27s QoS requirements

    Beaconless Packet Forwarding Approach for Vehicular Urban Environment

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    Existing wireless technologies provide communication and information services to all fields of life. The one of the emerging and popular field is vehicular ad hoc networks, with its unique characteristics and highly mobile environment. Different types of routing protocols have been proposed to address the routing issues in network and one of the most efficient types is geographical routing. In this type of protocols, the beacon messages are using to update the node locations and positions. However, these protoocls have been suffered with high channel congestion issue in the network. To this end, we propose a beaconless packet forwarding strategy based on modified handshake messages mechanism. The protocol uses some realistic metrics to select the next forwarder node such as forward progresss and link quality. The protocol performance is evaluated with existing beacon and beaconless geographical routing protocols. The simulation results showed the better performance of the proposed protocol in terms of packet delay and data delivery ratio in realistic wireless channel conditions

    Situational Awareness Enhancement for Connected and Automated Vehicle Systems

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    Recent developments in the area of Connected and Automated Vehicles (CAVs) have boosted the interest in Intelligent Transportation Systems (ITSs). While ITS is intended to resolve and mitigate serious traffic issues such as passenger and pedestrian fatalities, accidents, and traffic congestion; these goals are only achievable by vehicles that are fully aware of their situation and surroundings in real-time. Therefore, connected and automated vehicle systems heavily rely on communication technologies to create a real-time map of their surrounding environment and extend their range of situational awareness. In this dissertation, we propose novel approaches to enhance situational awareness, its applications, and effective sharing of information among vehicles.;The communication technology for CAVs is known as vehicle-to-everything (V2x) communication, in which vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) have been targeted for the first round of deployment based on dedicated short-range communication (DSRC) devices for vehicles and road-side transportation infrastructures. Wireless communication among these entities creates self-organizing networks, known as Vehicular Ad-hoc Networks (VANETs). Due to the mobile, rapidly changing, and intrinsically error-prone nature of VANETs, traditional network architectures are generally unsatisfactory to address VANETs fundamental performance requirements. Therefore, we first investigate imperfections of the vehicular communication channel and propose a new modeling scheme for large-scale and small-scale components of the communication channel in dense vehicular networks. Subsequently, we introduce an innovative method for a joint modeling of the situational awareness and networking components of CAVs in a single framework. Based on these two models, we propose a novel network-aware broadcast protocol for fast broadcasting of information over multiple hops to extend the range of situational awareness. Afterward, motivated by the most common and injury-prone pedestrian crash scenarios, we extend our work by proposing an end-to-end Vehicle-to-Pedestrian (V2P) framework to provide situational awareness and hazard detection for vulnerable road users. Finally, as humans are the most spontaneous and influential entity for transportation systems, we design a learning-based driver behavior model and integrate it into our situational awareness component. Consequently, higher accuracy of situational awareness and overall system performance are achieved by exchange of more useful information
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