Vehicular Ad Hoc Networks: Introduction and a proposal forvehicle positioning

The cost of vehicles in Iran compared to other countries are high. Most of peopleuse domestic mode vehicles with lower prices. Vehicles with lower prices do notcomply with many of the quality standards. Safety and standard systems such asairbags and anti-lock brakes are not fitted for such vehicles. So the most of theimmunization process should be done decentralized and out of the car for morereliability, covering more safety services and lower costs for the vehicle buyers.On the other side, in some cases, for the safety of the vehicle, it is necessary toreceive information from the outside of the vehicle. The driver uses these trafficand environmental information to become aware from circumstances ahead or tocollaborate with other vehicles for a safe operation. Many of the accidents aredue to negligence or failure in delivering proper information to drivers or failureto cooperate with the other vehicles. Therefore, we need a comprehensivecollaboration system as a safety net to provide many safety requirementsseamlessly. This goal will be achieved by using vehicular ad hoc network(VANET). This is the best solution to increase safety level with not much costfor the drivers in Iran. Only a few sensors and an onboard unit must be installedin the vehicle.The main goal of using this network is safety of human lives andtraffic efficiency on the roads. In this work after stating VANET requirementsand applications for expressing the need for its infrastructure investment in Iran,we focus more specifically on vehicle positioning that is used by many ofprotocols, algorithms and applications of VANET that their success depends ontheir ability to estimate an accurate vehicle position. There are various methodsfor vehicle positioning that usually safety applications need to be more accuratewith positioning methods. GPS is a simple and usual device for positioning inVANET. However the GPS signals are easily disturbed or obstructed andtherefore we can remove these effects from vehicle to vehicle communicationschemes for high traffic density roads or schemes that are using a specific RoadSide Units (RSUs) deployment for more accurate positioning. A security problemfor positioning methods is getting true and reliable positions from the vehicles.Fake position information has severe impact in the performance and security of1,2 {m.alimohammadi,apouyan}@shahroodut.ac.ir2position based applications. One of the applications that need to accuratepositions of vehicles is routing. The performance of routing applications may bedecrease if some of the vehicles maliciously send false positions. In addition tomalicious vehicles, positioning device may generate a fake position for thereason of malfunction of the sensing system (e.g. GPS receiver). Therefore in thispaper we suggest using an appropriate positioning method in VANET based onOU method. We prove this method has benefits for positioning and positionverification applications. We can use it when there is no position verificationmechanism or apply position verification mechanism after failing this method.This is more sufficient for urban areas because the number of RSUs is higher dueto the large number of intersections.

کلیدواژه ها:

Vehicular Ad hoc NETwork ، driver safety ، accident statistics ، the reason ofaccidents ، positioning ، position verification