LAB: Lightweight Adaptive Broadcast Control in DSRC Vehicular Networks

The dedicated short range communication (DSRC) is a spring-up technique that pushes intelligent transportation systems (ITS) into our habitual life. Intelligent transportation services involves safer and more coordinated way of using transport networks. Routine broadcast of vehicular safety messages is one of the perspectives of intelligent transportation systems. Developed countries such as Japan, USA and Europe customarily adopts FM0 and Manchester codes for DSRC in intelligent transportation systems to reach DC balance. Nonetheless, the coding diversity between the two codes restraints a fully reused VLSI architecture for the two coding methods. To unbound the limitation, the paper proposes similarity oriented logic simplification (SOLS) technique. The pressing feature of this technique is that it augments the hardware utilization rate (HUR) from 57.14% to 100% for the two encoding methods. The proposed architecture can fully support the DSRC standards of the developed countries. To enhance the efficiency of DSRC applications, the paper also proposes error detection and error correction through hamming codes. Hamming codes are used for error control. This paper ensures an error-free DSRC communication system along with area and power efficient encoder design. The paper is simulated in ModelSim 6.3f using VHDL. The design is implemented in Spartan 6 XC6SLX16.

IEEE- and ASTM-adopted Dedicated Short Range Communications (DSRC) vehicle safety-related communication services, which require reliable and fast message delivery, usually demand broadcast communications in vehicular ad hoc networks (VANETs). In this paper, we propose and justify a distributive robust scheme for DSRC one-hop safety-critical services. The new scheme enhances broadcast reliability using dynamic receiver-oriented packet repetitions and mini-slot within DIFS in IEEE 802.11 for one-hop emergency warning message dissemination. In addition, we investigate the reliability and performance of the proposed broadcast scheme for DSRC VANET safety-related services on highway analytically and by simulations. The analytic model accounts for the impact of the beacon message broadcast and the fading channel conditions on the reliability and performance.

Message dissemination issue in Vehicular ad hoc networks (VANETs) has been extensively studied both by computer simulations and experimental testbeds. Dedicated Short Range Communications (DSRC) technology has been standardized and used extensively as the main mechanism to support the message dissemination in VANETs. Nevertheless, other alternatives such as 3G/4G and WLAN have also been proposed to further assist with the message dissemination in VANETs. Due to the ubiquity of the smartphones, in this paper, we propose to leverage the use of smartphone to disseminate message in VANETs. An android-based system that uses WLAN ad-hoc technology is proposed. The feasibility and performance of the proposed system are investigated by simulations and the evaluation results show that given the high penetration of smartphones, the message dissemination can be done via the smartphones. Although the delay performance of the proposed system is inferior to DSRC-based system, the proposed system could still be very useful especially during the deployment stage of the DSRC technology (when the penetration rate of the technology is low).

Intelligent transportation system (ITS) is becoming an important part of our society. Vehicular ad hoc networks (VANETs), as one of the most fundamental technologies in ITS, have attracted great interests in both industry and academia. Due to ever-increasing data demands in VANETs, it is challenging to meet the requirements of ITS, especially for safety-critical applications. Fog computing is an emerging paradigm with the vision of supporting low communication latency, enhancing quality of service, and improving efficiency of network. Meanwhile, collision warning (CW) is critical for enhancing driving safety, which has stringent timing requirement. This work is dedicated to addressing safety issues in VANETs by designing and implementing a fog computing based collision warning system. Distinguishing from conventional cloud-based solutions, where vehicles have to communicate with servers resided in the backbone network via cellular network, the fog computing based system offloads communication and computation workloads to the infrastructures which are closer to end users (i.e., vehicles). In particular, the road-side unit (RSU) with dedicated short range communication (DSRC) interface and local computation unit is acted as the fog node, and it is installed at the road intersection. Then, vehicles approaching to the intersection will periodically report their status including positions, speed, driving direction and acceleration, to the RSU via DSRC. Based on the collected real-time status of surrounding vehicles, a collision prediction algorithm is designed and implemented in the computation unit of the fog node. The warning message will be triggered if potential collision is detected, and it will be transmitted to corresponding vehicles. For performance evaluation, we have implemented the system in realistic VANETs scenario. In addition, we have also implemented a cloud computing based CW system for performance comparison, where the LTE interface is adopted for transmitting messages to the cloud server, where the collision prediction algorithm is executed. Based on the field testing, we have demonstrated the superiority of the fog computing based CW system in terms of enhancing driving safety by providing real-time communication and distribute computation capabilities.

The rapid development of the supply chain of the Internet of Things (IoT) industry may trigger financial risk contagion among IoT manufacturers. This article collects data on listed IoT companies in the Chinese market from 2010 to 2019 and explores the development of the environment for the IoT industry. Two dynamic time wrapping (DTW) networks are created to analyze the topological structures of the IoT industry environment. Both the standard DTW and strongly connected DTW networks are revolutionary in terms of their interconnectedness in the IoT industry. We found that the level of clustering and transitivity of the network continued to decline between 2010 and 2019; i.e., the efficiency of financial risk contagion on IoT networks was significantly reduced. This article contributes to the literature in two aspects. First, it reveals that China's IoT industry is increasingly competitive; financial risks have become more difficult to transfer. The IoT industry has become more robust and exhibits a lower likelihood of financial risk contagion. Second, the article provides empirical evidence for the theory of coevolution, showing that risk contagion ability in an industry setting is decreasing with the development of individual firms.

Intelligent Transportation System (ITS) employ Vehicular Ad Hoc Network (VANET) to increase road safety and decrease thenumber of accidents. VANET uses Dedicated Short-Range Communications (DSRC) to allow drivers to obtain reasonable awareness of surrounding vehicles. VANET reliability is affected by any degradation in the communication channel or any lack of exchanged information between vehicles. Moreover, it is vulnerable to a wide range of malicious attacks due to its nature. Such issues might cause a complete failure in VANET services and hence cause accidents, injuries, or death. Thus, VANET reliability and security are very critical. This paper discusses briefly different types of malicious attacks in VANET and some of their detection techniques. It gives more attention to position falsification attack as it has a severe impact on different VANET services. Furthermore, it explores previously proposed detection approaches for this attack using either traditional or machine learning techniques. Finally, attention will be drawn to unresolved challenges and potential future research directions.

According to car crash statistics, over sixmillionmotor vehicle crashes occur onU.S. highways each year. More than 42,000 people are killed in these accidents which injure three million others, and cost more than $230 billion each year. Astonishingly, five people die every hour in these crashes in the United States which is about one death every 12 minutes IVI (2001). In order to alleviate the threats of these crashes and improve the driving experience, car manufactures and the telecommunication industry have made great efforts to equip each vehicle with wireless devices that allow vehicles to communicate with each other as well as with the roadside infrastructure located in critical points of the road, such as intersections or construction sites. Misener (2005); VII (2011). Technologies built on 802.11p and IEEE 1609 standards, 5.9 GHz Dedicated Short Range Communications (DSRC) protocols 1 DSRC (1999), are proposed to support these advanced vehicle safety applications such as secure and effective vehicle-to-vehicle (V2V) (also known as Inter-Vehicle Communication (IVC)) and vehicle-to-infrastructure (V2I) communications, which are also known as Vehicle Safety Communications (VSC) technologies. As shown in Fig. 1, the wireless communication devices installed on vehicles, also known as onboard units (OBUs), and the roadside units (RSUs), form a self-organized Vehicular Ad Hoc Network (VANET) Lin (2008); Sun (2007). Furthermore, the RSUs are connected to the backbone network via the high speed network connections. In this way, VANETs inherently provide a way to collect traffic and road information from vehicles, and to deliver road services including warnings and traffic information to users in the vehicles. Thus, an increasing interest has been raised recently on the VANETs-based applications Bishop (2000), aiming to improve driving safety and traffic management by the method of providing drivers and passengers with Internet access.

PurposeThe Internet of Things (IoT) provides exciting opportunities for the construction industry to solve its time and resource constraints and frequent defaults. This study seeks to identify and rank the perceived importance level of principal research areas associated with the IoT and the construction industry by utilising a scientific mapping tool (i.e. VOSviewer). Such knowledge would enable key drivers for successful adoption of the IoT and digitisation technologies to be outlined. An analysis of key drivers and research trends that facilitates the development of a roadmap for applying the IoT and digital technologies in the construction sector is therefore much needed.Design/methodology/approachAn interpretivist philosophical lens was adopted to analyse published work as secondary data, where each publication represented a unit of analysis. A total of 417 peer-reviewed journal review articles covering the IoT within the construction domain were systematically reviewed using a mixed-methods approach, utilising qualitative-scientometric analyses techniques.FindingsThe results revealed a field of study in a fledgling stage, with a limited number of experts operating somewhat in isolation and offering single-point solutions instead of taking an integrated “holistic” approach. Key publication outlets were identified and the main focus of research undertaken being in the technical areas of smart buildings, smart construction objects and environmental sustainability. The major effects of adopting the IoT within the construction industry were identified as high-speed reporting, complete process control, data explosion leading to deep data analytics, strict ethical and legal expectations. Key drivers of the IoT adoption were outlined: interoperability; data privacy and security; flexible governance structures; proper business planning and models.Practical implicationsThe study benefits researchers and industry practitioners alike. For researchers, the identified gaps reveal areas of high priority in future research. For construction companies, particularly small to medium-sized businesses, the study raises awareness of the latest developments and potential applicability of the IoT in the industry. For government agencies and policymakers, this study offers a point of reference in directing the adoption of the IoT smoothly in the construction sector and provides guidelines and standards for maximising the potential benefits.Originality/valueThe study is the first scientometric review of the existing body of knowledge in the context of application of the IoT in the construction industry. Findings expose knowledge gaps in contemporary research, specifically, a broader consideration of organisational adjustments needed to accommodate the IoT usage, economic analyses and impediments to wider acceptance.

Dedicated short-range communications (DSRC) is one of the key technologies enabling safety-critical applications for intelligent transportation system (ITS). Considering the significance of such safety-of-life applications, it is of utmost importance to guarantee reliable delivery of basic safety messages (BSMs). However, in accordance with a V2X network being inherently dynamic in key aspects such as vehicle density and velocity, the networking behavior of a DSRC system is usually highly complicated to analyze. In addition, the United States Federal Communications Commission (US FCC) recently proposed the so-called “5.9 GHz band innovation,”which includes a plan to reduce bandwidth for DSRC to 10 MHz at best from 75 MHz. Motivated from these challenges, the necessity of “lightening”load of a DSRC network has become essential to keep safety-related operations from performance deterioration. To this end, this paper proposes a protocol that prioritizes transmission of a BSM from a vehicle according to the level of accident risk of the vehicle. The proposed protocol uses the distance of a vehicle from a danger source as the metric to determine the priority for transmission. Our results show that this protocol effectively prioritizes the transmission opportunity for dangerous vehicles, and hence results in higher performance in terms of key metrics-i.e., average latency, packet delivery rate (PDR), and inter-reception time (IRT).

Reliability is an important issue for safety-critical broadcast services in vehicular ad hoc networks (VANETs). So far, most investigations of such broadcast networks focus on multihop connectivity, taking all one-hop links for granted. In this paper, four reliability metrics for one-hop broadcast communication in VANETs, including the packet reception rate (PRR), the packet delivery ratio (PDR), the node successful packet delivery probability (PDP), and the effective range (ER), are introduced and evaluated analytically and by simulations. Expressions of these reliability metrics for one-hop broadcast in IEEE-802.11-based 1-D VANETs are derived with consideration of the IEEE 802.11 distributed coordination function (DCF), the hidden terminal problem, and collisions caused by concurrent transmissions. The impacts of network parameters such as distinct transmission, carrier sensing, and interference ranges; the density of nodes in the networks; the distances of receivers to the senders; the message generation rates; the backoff window sizes; and the channel data rates on the reliability of the broadcast communication in VANETs are investigated and discussed. As an example, the proposed model is applied to the evaluation of the dedicated short-range communication (DSRC) safety-critical message propagation in a highway setting. As a result, some important observations to the design and analysis of such communication systems are provided.

Passive Cooperative Collision Warning (PCCW) MAC designs for reliable vehicular safety messaging

Basic Safety Messaging plays a crucial role to provide road safety in vehicular ad-hoc networks (VANETs). To avoid potential accidents, vehicles periodically broadcast safety information to neighboring vehicles. However, due to transmission collisions, fading channels and other factors, vehicular networks usually suffer a low packet delivery ratio (PDR) and a large delay, which are intolerant of many safety applications. To tackle these issues, this paper proposes a hybrid medium access control (MAC) protocol for basic safety message (BSM) dissemination based on the framework of Dedicated Short-Range Communication (DSRC). Its partially centralized and partially distributed characteristic not only can effectively suppress the collisions, but keep compatibility with IEEE 802.11p. In addition, the integration of Physical-Layer Network Coding (PNC) and Random Linear Network Coding (RLNC) further strengthens the reliability and efficiency for BSM dissemination. Both the theoretical analysis and comprehensive simulations indicate that, compared with existing schemes, the proposed protocol can significantly improve the PDR by a range of 20% to 300%. Meanwhile, in terms of normalized throughput, it increases by varying percent between 20% and 160% in different scenarios.

Vehicle-to-everything (V2X) communications have become a key enabler for future autonomous driving by providing sensing and cooperation abilities beyond traditional on-board sensors. The main candidate technologies for V2X communications are dedicated short range communication (DSRC)/IEEE 802.11p and long-term evolution (LTE), each of which has its own strengths and weaknesses. DSRC provides low-latency direct connectivity, but suffers from serious link degradation and reliability issues. On the other hand, LTE is able to provide high capacity data transmission, while its latency remains an issue due to the long transmission time interval. Integrating these two radio technologies as a heterogeneous solution is promising to complement each other and support V2X applications with differentiated service requirements. This paper proposes a service-aware radio access technology (RAT) selection algorithm that enables a heterogeneous LTE/DSRC solution, where LTE and/or DSRC are selected according to services. Each vehicle is assumed to be equipped with both LTE and DSRC interfaces. The heterogeneous solution selects RAT based on the services requirements with consideration of the networks performance. The solution is implemented with integration of the C-ITS standard and validated through the OMNet++ and SUMO based network simulator. A see-through scenario, where a fleet of vehicles require real-time video data sharing to assist efficient driving, is considered. The simulation results demonstrate that the proposed approach outperforms the purely DSRC approach significantly and is able to simultaneously support safety message transmission with low latency, video streaming with high bandwidth requirements, and other applications with different service requirements.

Heterogeneous cellular and DSRC networking for Floating Car Data collection in urban areas

The important goal in designing the Medium Access Control (MAC) layer in Vehicular Ad hoc Networks (VANETs) is to provide reliable safety message broadcast and efficient non-safety message transmissions to vehicles. This paper proposes the Directional Multi-channel MAC protocol for VANETs, named DMV protocol, which provides safety message broadcast reliability and high service channel utilization. Both TDMA and CSMA access schemes are supported, and directional antennas are employed in the DMV protocol. The simulation results show that DMV outperforms IEEE 1609.4 in terms of packet delivery ratio of safety messages and throughput of non-safety messages at the price of complex data structures.