Search

This paper studies the problem of non-cooperative radio resource scheduling in a vehicle-to-vehicle communication network. The technical challenges lie in high vehicle mobility and data traffic variations. Over the discrete scheduling slots, each vehicle user equipment (VUE)-pair competes with other VUE-pairs in the coverage of a road side unit (RSU) for the limited frequency to transmit queued packets. The frequency allocation at the beginning of each slot by the RSU is regulated following a sealed second-price auction. Each VUE-pair aims to optimize the expected long-term performance. Such interactions among VUE-pairs are modelled as a stochastic game with a semi-continuous global network state space. By defining a partitioned control policy, we transform the stochastic game into an equivalent game with a global queue state space of finite size. We adopt an oblivious equilibrium (OE) to approximate the Markov perfect equilibrium (MPE), which characterizes the optimal solution to the equivalent game. The OE solution is theoretically proven to be with an asymptotic Markov equilibrium property. Due to the lack of a priori knowledge of network dynamics, we derive an online algorithm to learn the OE policies. Numerical simulations validate the theoretical analysis and show the effectiveness of the proposed online learning algorithm.

The use of Visible Light Communications (VLC) in vehicular applications has become a major research area due to its simplicity, high performance to cost ratio, and great deployment potential. In this context, this article provides one of the very few analyses and experimental evaluations concerning the integration of a light dimming function in vehicular VLC systems. For this purpose, a vehicle-to-vehicle VLC prototype has been implemented and used to evaluate the systems’ communication performances in light dimming conditions, while decreasing the duty cycle from 40% to 1%, and increasing the communication range from 1 to 40–50 m. The experimental results showed that in normal lighting conditions, the VLC technology can easily support low duty cycle light dimming for ranges up to 40 m, while maintaining a 10−6 BER. Nevertheless, in strong optical noise conditions, when the system reaches its SNR limit, the communication range can decrease by half, whereas the BER can increase by 2–4 orders of magnitude. This article provides consistent evidence concerning the high potential of the VLC technology to support inter-vehicle communication links, even in light dimming conditions.

The use of visible light communications technology in communication-based vehicle applications is gaining more and more interest as the research community is constantly overcoming challenge after challenge. In this context, this article addresses the issues associated with the use of Visible Light Communications (VLC) technology in Vehicle-to-Vehicle (V2V) communications, while focusing on two crucial issues. On the one hand, it aims to investigate the achievable communication distance in V2V applications while addressing the least favorable case, namely the one when a standard vehicle rear lighting system is used as a VLC emitter. On the other hand, this article investigates another highly unfavorable use case scenario, i.e., the case when two vehicles are located on adjacent lanes, rather than on the same lane. In order to evaluate the compatibility of the VLC technology with the usage in inter-vehicle communication, a VLC prototype is intensively evaluated in outdoor conditions. The experimental results show a record V2V VLC distance of 75 m, while providing a Bit Error Ratio (BER) of 10−7–10−6. The results also show that the VLC technology is able to provide V2V connectivity even in a situation where the vehicles are located on adjacent lanes, without a major impact on the link performances. Nevertheless, this situation generates an initial no-coverage zone, which is determined by the VLC receiver reception angle, whereas in some cases, vehicle misalignment can generate a BER increase that can go up to two orders of magnitude.

Direct-conversion architectures can offer highly integrated low-cost hardware solutions to communication transceivers. However, it has been demonstrated that radio frequency (RF) impairments such as amplifier nonlinearities, phase noise, and in-phase/quadrature-phase imbalances (IQI) can lead to severe degradation of the performance of such systems. Motivated by this, the present work is devoted to the quantification and evaluation of the effects of RF IQI on wireless communications in the context of cascaded fading channels for both single-carrier and multicarrier systems. To this end, closed-form expressions are first derived for the outage probability (OP) over $N^{\ast}$ Nakagami- $m$ channels for the cases of ideal transmitter (TX) and receiver (RX), ideal TX and IQI RX, IQI TX and ideal RX, and joint TX/RX IQI. The offered expressions, along with several deduced corresponding special cases, are subsequently employed in vehicle-to-vehicle (V2V) communications to justify their importance and practical usefulness in the context of emerging communication systems. The offered analytic results are corroborated by extensive comparisons with respective results from computer simulations. It is shown that considering non-ideal RF front-ends at the TX and/or RX introduces nonnegligible errors in the OP performance that can exceed 20% under several communication scenarios. It is further demonstrated that the effects by cascaded multipath fading conditions are particularly detrimental as they typically result in considerable performance losses of around or over an order of magnitude.

1st International Telecommunications Conference, ITelCon 2017 -- 28 December 2017 through 29 December 2017 -- -- 215829 Green transportation is an integral part of green environment concept. Next generation transportation systems are desired to achieve high performances with reduced fuel consumption and carbon emission. In this regard, vehicle maintenance status along with some other critical diagnostic data should steadily be checked and tracked. It is known that vehicles that are poorly maintained or not maintained in a timely manner lead to both emissions exceeding the standards and low performance. Vehicle telematics along with some other conveniences such as infotainment systems, location–based services and applications are expected to improve safety, availability, and reliability of next generation transportation systems. From this perspective, intelligent transport systems (ITS) seems to be a promising solution candidate which encompasses all of the aforementioned topics as well as vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), and vehicle-to-cloud (V2C) opportunities. Therefore, in this study, a conceptual model that links vehicle telematics to the cloud along with V2V communications facility is proposed and a prototype based on IEEE 802.11x protocol suite is implemented. Mobile data collection and measurements are obtained. Results are presented along with relevant discussions as well as the end point storage and usage of the data are introduced. In the proposed model, the mobile data are transferred to cloud computing platform to create the big data for further research opportunities for car manufacturers, policy makers, and researchers with the concern of ethics and security issues. © 2019, Springer Nature Singapore Pte Ltd.

Automakers are increasingly employing wireless communications technologies into vehicles, which are expected to be one of the primary tools to improve traffic flow and traffic safety. Anticipating a significant increase in the accompanying spectrum and capacity requirements, in this paper, we speculate about using dynamic spectrum access in general, and TV white space in particular for vehicular communications. To this end, we describe the concept, design, general architecture and operation principles of a vehicle-to-vehicle communications system over TV white space. This system makes dual use of a geolocation database and spectrum sensing to understand spectrum vacancies. In this architecture, whenever a database query result is available, that information is prioritized over sensing results and when the database access is disrupted, vehicles rely on the spectrum sensing results. After describing the general concepts, we numerically analyze and evaluate the benefits of using proxy vehicles for geolocation database access. Finally, we present the middleware-centric implementation and field test results of a multi-hop vehicle-to-vehicle communications system over the licensed TV-band. We present results regarding multi-hop throughput, delay, jitter, channel switching and database access latencies. This study complements our previous work which described spectrum sensing based vehicle-to-vehicle communications design and testing.

Communications systems operating in the millimeter-wave (mmWave) and terahertz (THz) band have been recently suggested to enable high data-rate vehicle-to-vehicle (V2V) communications in 5G and beyond wireless networks. However, massive deployment of such systems may lead to significant interference, affecting the performance of information transmission. While the multipath interference caused by the signal reflections from the road has been extensively discussed in the literature, the interference caused by the vehicles on the side lanes has been insufficiently studied so far. In this paper, using a combination of measurement, simulation, and analytical methods, we comprehensively characterize the interference from the side lanes in two typical deployments including highway and urban road environments for millimeter-wave and low terahertz bands. Both the multipath interference and direct interference from the transmitting vehicles on the side lanes are taken into account. As a result of our study, we reveal that: the interference from the side lanes can be well approximated using two-dimensional stochastic models without any significant loss of accuracy; and even when highly directional antennas are used there are special spatial configurations, where the interference may greatly affect the performance of the communication systems. We lately apply the developed models to estimate the signal-to-interference ratio and link capacity of mmWave/THz band V2V communications.

This work investigates the performance of a multi- hop scheme for the dissemination of road safety messages on highway segments, employing the recently standardized LTE-A Cellular Vehicle- to- Everything (C-V2X) technology. In order to guarantee a seamless service in areas where cellular coverage is unavailable, vehicles direcly communicate over the unlicenced ITS 5.9 GHz frequency band, operating in accordance to Mode 4 of the C-V2X standard. The proposed scheme and the examined use-case demonstrate that the delivery of safety messages can successfully take place on a dedicated radio channel, as well as on a shared channel where periodic messages are broadcast at the maximum frequency foreseen by ETSI.

To improve vehicle safety, vehicular ad hoc networks (VANETs) periodically broadcast safety messages known as beacons. Consequently, it becomes safety critical to guarantee the timely reception of periodic beacons under the time-varying environments of VANET. However, existing approaches typically measure the packet delivery ratio, which is a time-average metric that does not consider the temporal behavior associated with beacon reception. In this paper, to properly reflect the temporal aspect of beacon reception, we propose a congestion control algorithm, Beacon inter-reception time Ensured Adaptive Transmission (BEAT). The proposed algorithm tightly regulates the beacon inter-reception time compared to conventional techniques, which can significantly improve vehicle safety. Our simulation results demonstrate the effectiveness of the proposed scheme.

Advertisement (ad) delivery is expected to play a crucial role in future vehicular networks. In this article, we examine how ads can be broadcasted by roadside units (RSUs) as well as vehicles and then displayed to interested users. We describe the ad dissemination process by means of an optimization model that aims to maximize the number of ads that users display within the target area and validity period of the ad. We then solve the optimization problem, obtaining the optimal scheduling strategy that RSUs and vehicles should adopt for ad broadcasting. Our study highlights the important role that vehicle-to-vehicle (V2V) communications will have in ad delivery. Also, it shows how coexisting vehicular and cellular networks can effectively complement each other, with vehicular networks being a very efficient means for pervasive ad dissemination.

For vehicle-to-vehicle (V2V) communication, such issues as continuity and reliability still have to be solved. Specifically, it is necessary to consider a more scalable physical layer due to the high-speed mobility of vehicles and the complex channel environment. Adaptive transmission has been adapted in channel-dependent scheduling. However, it has been neglected with regards to the physical topology changes in the vehicle network. In this paper, we propose a physical topology-triggered adaptive transmission scheme which adjusts the data rate between vehicles according to the number of connectable vehicles nearby. Also, we investigate the performance of the proposed method using computer simulations and compare it with the conventional methods. The numerical results show that the proposed method can provide more continuous and reliable data transmission for V2V communications.

International audience; Various "Urban Transportation Systems" are currently in developing, in order to put forward solutions to congestion and pollution in dense areas. Autonomous electric vehicles in free-access can be seen as an attractive approach, in view of the large flexibility that can be expected. One instrumental functionality linked to this solution is platoon motion: several autonomous vehicles accurately follow a trajectory defined on a dedicated circulation lane, with pre-specified inter-distances. A global decentralized platoon control strategy, supported by inter-vehicle communications and relying on nonlinear control techniques is here proposed. In the nominal case, each vehicle is controlled with respect to the same smooth reference trajectory modelled by cubic B-Splines. This trajectory is locally modified and relayed on-line when a vehicle detects an obstacle. The trajectory distortion naturally reflects a driver's behaviour, since it consists in approximated clothoidal trajectories and the use of B-Splines ensures consistent connections. Experimental results, carried out with several urban vehicles, demonstrate the capabilities of the proposed approach.