A Measurement Based Shadow Fading Model for Vehicle-to-Vehicle Network Simulations

The vehicle-to-vehicle (V2V) propagation channel has significant implications on the design and performance of novel communication protocols for vehicular ad hoc networks (VANETs). Extensive research efforts have been made to develop V2V channel models to be implemented in advanced VANET system simulators for performance evaluation. The impact of shadowing caused by other vehicles has, however, largely been neglected in most of the models, as well as in the system simulations. In this paper we present a shadow fading model targeting system simulations based on real measurements performed in urban and highway scenarios. The measurement data is separated into three categories, line-of-sight (LOS), obstructed line-of-sight (OLOS) by vehicles, and non line-of-sight due to buildings, with the help of video information recorded during the measurements. It is observed that vehicles obstructing the LOS induce an additional average attenuation of about 10 dB in the received signal power. An approach to incorporate the LOS/OLOS model into existing VANET simulators is also provided. Finally, system level VANET simulation results are presented, showing the difference between the LOS/OLOS model and a channel model based on Nakagami-m fading.Comment: 10 pages, 12 figures, submitted to Hindawi International Journal of Antennas and Propagatio

Line-of-Sight Obstruction Analysis for Vehicle-to-Vehicle Network Simulations in a Two-Lane Highway Scenario

In vehicular ad-hoc networks (VANETs) the impact of vehicles as obstacles has largely been neglected in the past. Recent studies have reported that the vehicles that obstruct the line-of-sight (LOS) path may introduce 10-20 dB additional loss, and as a result reduce the communication range. Most of the traffic mobility models (TMMs) today do not treat other vehicles as obstacles and thus can not model the impact of LOS obstruction in VANET simulations. In this paper the LOS obstruction caused by other vehicles is studied in a highway scenario. First a car-following model is used to characterize the motion of the vehicles driving in the same direction on a two-lane highway. Vehicles are allowed to change lanes when necessary. The position of each vehicle is updated by using the car-following rules together with the lane-changing rules for the forward motion. Based on the simulated traffic a simple TMM is proposed for VANET simulations, which is capable to identify the vehicles that are in the shadow region of other vehicles. The presented traffic mobility model together with the shadow fading path loss model can take in to account the impact of LOS obstruction on the total received power in the multiple-lane highway scenarios.Comment: 8 pages, 11 figures, Accepted for publication in the International Journal of Antennas and Propagation, Special Issue on Radio Wave Propagation and Wireless Channel Modeling 201

An optimal system design process for a Mars roving vehicle

The problem of determining the optimal design for a Mars roving vehicle is considered. A system model is generated by consideration of the physical constraints on the design parameters and the requirement that the system be deliverable to the Mars surface. An expression which evaluates system performance relative to mission goals as a function of the design parameters only is developed. The use of nonlinear programming techniques to optimize the design is proposed and an example considering only two of the vehicle subsystems is formulated and solved

A Survey of Air-to-Ground Propagation Channel Modeling for Unmanned Aerial Vehicles

In recent years, there has been a dramatic increase in the use of unmanned aerial vehicles (UAVs), particularly for small UAVs, due to their affordable prices, ease of availability, and ease of operability. Existing and future applications of UAVs include remote surveillance and monitoring, relief operations, package delivery, and communication backhaul infrastructure. Additionally, UAVs are envisioned as an important component of 5G wireless technology and beyond. The unique application scenarios for UAVs necessitate accurate air-to-ground (AG) propagation channel models for designing and evaluating UAV communication links for control/non-payload as well as payload data transmissions. These AG propagation models have not been investigated in detail when compared to terrestrial propagation models. In this paper, a comprehensive survey is provided on available AG channel measurement campaigns, large and small scale fading channel models, their limitations, and future research directions for UAV communication scenarios

Path loss modeling for vehicular system performance and communicaitons protocols evaluation

Vehicular communications are receiving considerable attention due to the introduction of the intelligent transportation system (ITS) concept, enabling smart and intelligent driving technologies and applications. To design, evaluate and optimize ITS applications and services oriented to improve vehicular safety, but also non-safety applications based on wireless systems, the knowledge of the propagation channel is vital. In particular, the mean path loss is one of the most important parameters used in the link budget, being a measure of the channel quality and limiting the maximum allowed distance between the transmitter (Tx) and the receiver (Rx). From a narrowband vehicular-to-vehicular (V2V) channel measurement campaign carried out at 5.9 GHz in three different urban environments characterized by high traffic density, this paper analyzes the path loss in terms of the Tx-Rx separation distance and fading statistics. Based on a linear slope model, values for the path loss exponent and the standard deviation of shadowing are reported. We have evaluated the packet error rate (PER) and the maximum achievable Tx-Rx separation distance for a PER threshold level of 10% according to the digital short-range communications (DSRC) specifications. The results reported here can be incorporated in an easy way to vehicular networks (VANETs) simulators in order to develop, evaluate and validate new protocols and systems architecture configurations under realistic propagation conditions.Fernández González, HA.; Rubio Arjona, L.; Reig, J.; Rodrigo Peñarrocha, VM.; Valero-Nogueira, A. (2013). Path loss modeling for vehicular system performance and communicaitons protocols evaluation. Mobile Networks and Applications. 18(6):755-765. doi:10.1007/s11036-013-0463-xS755765186Gallager B, Akatsuka H, Suzuki H (2006) Wireless communications for vehicle safety: radio link performance and wireless connectivity. IEEE Veh Technol Mag 1(4):4–24Rubio L, Reig J, Fernández H (2011) Propagation aspects in vehicular networks, Vehicular technologies. Almeida M (ed) InTechWang C-X, Vasilakos A, Murch R, Shen SGX, Chen W, Kosch T (2011) Guest editorial. Vehicular communications and networks – part I. IEEE J Select Areas Commun 29(1):1–6ASTM E2213-03 (2003) Standard specification for telecommunications and information exchange between roadside and vehicle systems – 5 GHz band Dedicated Short Range Communications (DSRC) Medium Access Control (MAC) and Physical Layer (PHY) specifications. American Society for Testing Materials (ASTM), West ConshohockenIEEE 1609 – Family of Standards for Wireless Access in Vehicular Environments (WAVE). [Online]. Available: http://www.standards.its.dot.govETSI TR 102 492–2 Part 2 (2006) Technical characteristics for Pan European Harminized Communications Equipment Operating in the 5 GHz frequency range intended for road safety and traffic management, and for non-safety related ITS applications, European Telecommunications Standard Institute (ETSI), Technical Report, Sophia Antipolis, FranceThe Car-to-Car Communication Comsortium (C2CC): http:/www.car-to-car.orgMecklenbräuker C, Molisch A, Karedal J, Tufvesson F, Paier A, Bernado L, Zemen T, Klemp O, Czink N (2011) Vehicular channel characterization and its implications for wireless system design and performance. IEEE Proc 99(7):1189–1212Ghafoor KZ, Bakar KA, Lloret J, Khokhar RH, Lee KC (2013) Intelligent beaconless geographical routing for urban vehicular environments. Int J Wireless Netw 19(3):345–362Ghafoor KZ, Lloret J, Bakar KA, Sadiq AS, Mussa SAB (2013) Beaconing approaches in vehicular ad hoc networks: a survey. Int J Wirel Pers Commun. Published Online (May 2013)Michelson DG, Ghassemzadeh SS (2009) New directions in wireless communications, Springer Science+Busines Media (Chapter 1)IEEE 802.11p (2010) Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications Amendment 6: Wireless Access in Vehicular Environments, Institute of Electrical and Electronic Engineers (IEEE), New York, USA.Karedal J, Czink N, Paier A, Tufvesson F, Moisch AF (2011) Path loss modeling for vehicle-to-vehicle communications. IEEE Trans Veh Technol 60(1):323–327Cheng L, Henty B, Stancil D, Bai F, Mudalige P (2007) Mobile vehicle-to-vehicle narrow-band channel measurement and characterization of the 5.9 GHz dedicated short range communication (DSRC) frequency band. IEEE J Select Areas Commun 25(8):1501–1516Cheng L, Henty B, Cooper R, Stancil D, Bai F (2008) Multi-path propagation measurements for vehicular networks at 5.9 GHz. IEEE Wireless Communications and Networking Conference, pp. 1239–1244Tan I, Tang W, Laberteaux K, Bahai N (2008) Measurement and analysis of wireless channel impairments in dsrc vehicular communications. IEEE International Conference on Communications, pp. 4882–4888.Campuzano AJ, Fernández H, Balaguer D, Vila-Jiménez A, Bernardo-Clemente B, Rodrigo-Peñarrocha VM, Reig J, Valero-Nogueira A, Rubio L (2012) Vehicular-to-vehicular channel characterization and measurement results. WAVES 4(1):14–24Kunisch J, Pamp J (2008) Wideband car-to-car radio channel measurements and model at 5.9 GHz. IEEE 68th Vehicular Technology Conference, pp. 1–5Gozalvez J, Sepulcre M (2007) Opportunistic technique for efficient wireless vehicular communications. IEEE Veh Technol Mag 2(4):33–39Zang Y, Stibor L, Orfanos G, Guo S, Reumerman H (2005) An error model for inter-vehicle communications in highway scenarios at 5.9 GHz. Proc. Int. Workshop on performance evaluation of wireless ad hoc, sensor, and ubiquitous networks, pp. 49–5

Experimental investigation of V2I radio channel in an arched tunnel

This paper describes the results of the experimental radio channel sounding campaign performed in an arched road tunnel in Le Havre, France. The co-polar and cross-polar channels measurements are carried out in the closed side lane, while the lane along the center of the tunnel is open to traffic. We investigate the channel characteristics in terms of: path loss, fading distribution, polarization power ratios and delay spread. All these parameters are essential for the deployment of vehicular communication systems inside tunnels. Our results indicate that, while the H-polar channel gain attenuates slower than the V-polar channel due to the geometry of the tunnel, the mean delay spread of the H-polar channel is larger than that of the V-polar channel

Pose Detection and control of multiple unmanned underwater vehicles using optical feedback

This paper proposes pose detection and control algorithms in order to control the relative pose between two Unmanned Underwater Vehicles (UUVs) using optical feedback. The leader UUV is configured to have a light source at its crest which acts as a guiding beacon for the follower UUV which has a detector array at its bow. Pose detection algorithms are developed based on a classifier, such as the Spectral Angle Mapper (SAM), and chosen image parameters. An archive look-up table is constructed for varying combinations of 5-degree-of-freedom (DOF) motion (i.e., translation along all three coordinate axes as well as pitch and yaw rotations). Leader and follower vehicles are simulated for a case in which the leader is directed to specific waypoints in horizontal plane and the follower is required to maintain a fixed distance from the leader UUV. Proportional-Derivative (PD) control (without loss of generality) is applied to maintain stability of the UUVs to show proof of concept. Preliminary results indicate that the follower UUV is able to maintain its fixed distance relative to the leader UUV to within a reasonable accuracy

The COST IRACON Geometry-based Stochastic Channel Model for Vehicle-to-Vehicle Communication in Intersections

Vehicle-to-vehicle (V2V) wireless communications can improve traffic safety at road intersections and enable congestion avoidance. However, detailed knowledge about the wireless propagation channel is needed for the development and realistic assessment of V2V communication systems. We present a novel geometry-based stochastic MIMO channel model with support for frequencies in the band of 5.2-6.2 GHz. The model is based on extensive high-resolution measurements at different road intersections in the city of Berlin, Germany. We extend existing models, by including the effects of various obstructions, higher order interactions, and by introducing an angular gain function for the scatterers. Scatterer locations have been identified and mapped to measured multi-path trajectories using a measurement-based ray tracing method and a subsequent RANSAC algorithm. The developed model is parameterized, and using the measured propagation paths that have been mapped to scatterer locations, model parameters are estimated. The time variant power fading of individual multi-path components is found to be best modeled by a Gamma process with an exponential autocorrelation. The path coherence distance is estimated to be in the range of 0-2 m. The model is also validated against measurement data, showing that the developed model accurately captures the behavior of the measured channel gain, Doppler spread, and delay spread. This is also the case for intersections that have not been used when estimating model parameters.Comment: Submitted to IEEE Transactions on Vehicular Technolog