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

Taimoor Abbas,Fredrik Tufvesson,Katrin Sjöberg,Johan Karedal

doi:10.1155/2015/190607

Abstract

The vehicle-to-vehicle (V2V) propagation channel has significant implications on the design and performance of novel communication protocols for vehicularad hocnetworks (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-mfading.

Highlights

Vehicle-to-Vehicle (V2V) communication allows vehicles to communicate directly with minimal latency
A shadow fading model based on measurements performed in urban and highway scenarios is presented, where a separation between LOS, obstructed LOS by vehicle (OLOS), and obstructed LOS by building (NLOS), is performed
We have observed that the LOS obstruction by vehicles (OLOS) induce an additional loss, of about 10 dB, in the received power

Summary

Introduction

Vehicle-to-Vehicle (V2V) communication allows vehicles to communicate directly with minimal latency. In [5], it is reported that the received signal strength degrades on the same patch of an open road in heavy traffic hours as compared to when there is light traffic These observed differences can only be related to other vehicles obstructing LOS since the system parameters remained the same during the measurement campaign. Simulation results are presented where the results obtained from the LOS/OLOS model are compared against Cheng’s model [24], which is based on an outdoor channel sounding measurement campaign performed at 5.9 GHz. The reason of choosing Cheng’s model for comparison is that the Cheng’s model do not classify measured data as LOS, OLOS, and NLOS, but it represents both the small-scale fading and the shadowing by the Nakagami-m model.

Methodology

Channel Model

Network Simulations

Findings

Summary and Conclusions