Vehicle ad-hoc Network (VANETS) Technology

fomite ad-hoc Net feed (VANETS) TechnologyChapter 1IntroductionNow a day, everything is moving away from wired technology and jumper lead towards wireless. The fascination of mobility, rise to poweribility and flexibility dissembles wireless technologies the dominant method of transferring all sorts of data. Satellite tele mickles, cellular phones and wireless Internet are well-known covers of wireless technologies. This work presents a promising wireless activity and introduces a tiny contribution to its research comm unity. look in wireless chat field is growing faster, day by day, thence all other(a) field. It serves a very br step to the foree range or series of different kind of applications using different topologies. all one of these comes with virtually new and specialized protocols. In this research, we give present an introduction to a wireless technology. This wireless technology directly affects simple machine accidents and the gross sales of one of the larg est markets. It is the technology of building a strong lucre amidst mobile vehicles i.e. let vehicles communicate to each other. This promising technology is literally called vehicular Ad-Hoc Networks (VANETs).1.1 BackgroundSince the first invention of mobile vehicles, governments and manufacturers fall in researched accidents to number the number of vehicle crashes in order to reduce costs, injuries and fatalities. First of all, VANET technology is going to reduce crashes by doing research in this field. Accordingly, link up governmental authorities initiated new put ups to the learning institute for study, research, development in the field of wireless technology and VANETs in like manner paying attention in its regulars. The Dedicated Short Range communications (DSRC) 1 is a pioneer ITS (Intelligent Transportation Systems which is a branch of the U.S. Department of Transportation 2) project dedicated to VANET standardization. Then, the acronym or short form DSRC becom es a global or familiar name of kind of standards that aim to put VANET technology into life. The DSRC mainly concerns with the discourse that is how to make different communication links between vehicle-to-vehicle and vehicle-to/from-road spot units.1.2 MotivationIn the last few years, vehicular network has gained great attention in industry. federal communication commission (FCC) has assigned 5.850-5.925GHZ frequency band to promote safe and efficient road trips, which is planned for vehicle-to-vehicle and vehicle-to-infrastructure communication. Car manufacturers, e.g., Audi, BMW and DaimlerChrysler, too formed a Car2Car communication consortium 3, in which the prototype development for inter-vehicle communications is underway.In near past, IEEE 802.11-based solutions for VANETs are similarly studied by IEEE 802.11p. IEEE 802.11p Wireless Access in the vehicular Environment ( pother) that defines changes to IEEE 802.11 to help Intelligent Transportation Systems (ITS) applicat ions. IEEE 802.11p helps data shifts between fast moving vehicles with each other and excessively exchanges data from vehicles to road side unit or from road side unit to vehicles in the licensed ITS band of 5.9 gigacycle per second. The Dedicated Short-Range Communications (DSRC) at 5.9 GHz is here today to admit caoutchouc that is increasing sentry duty in case of road accidents, reducing lastway or road maintenance cost and also change mobility. inter momenttion point and road departure strikings report for round about 50 percent of all crashes and victims on our roads. On an average day in the United States, vehicular collisions kill 116 and injure 79008. more health care dollars are consumed in the United States treating crash victims than any other ca manipulation of illness or soil 8, 10 the situation in the European Union is similar, with over 100 deaths and 4600 injuries daily, and the annual cost of 160 billion 11. By getting rid from road victims and crashes, DSRC enkindle provide or play important role in reducing road accidents, deaths, injuries, heavy concern and increasing road safety by improving communication between vehicles and between vehicles and road side infrastructure. DSRC emerged from a partnership among automobile manufacturers, state and federal transportation officials, toll transponder equipment suppliers and the Federal Communications care. thither is a recognized need for on-the-go communication with motor vehicles and reliable communication between vehicles to increase highway safety by providing warnings and alerts that enable device drivers to take nonindulgent and/or evasive actions. At the same time, it can be able to provide information i.e. real time information to drivers so that to improve mobility and motorist convenience, such as information on congestion or traffic incidents. The car manufacturing industrys determination to roll out vehicle-to-vehicle communication in the near proximo tense and, on the other hand, to the increasing disillusionment concerning the need for the vast number of protocols developed for general Mobile Ad-Hoc Networks (MANETs) in the past few years piece on the other side that is for VANETs, industry pressure has created a situation in which an overwhelming interest in solutions to fusss leads to a preference for real- instauration research as opposed to fancy theory. As the concept came from MANETs which totally depend on the subscribers motion as the motion is random it is difficult to cater it but this problem was very negligible when researchers observed it in VANETS. At highways vehicle move in an organized pattern with different focal ratios so initially it seemed that VANET will considerably be implemented. A nonher major reason for VANET can be transaction deaths and injuries which is a major health and social issue. While industrialized nations (e.g., the United States) have continuously reduced annual traffic deaths since 1970, annual traffic-related fatalities and injuries remain high (in the United States alone at that place were over 41,000 deaths and 5 million injuries in 2000, jibe to the NHTSA) 7. The economic impact of vehicle crashes in the United States exceeded US$230 billion or 2.3 percent of the U.S. GDP in 2000 7. We want to remain connected with the world through net whether at home, contrastport, at work or even on the roads.ExampleDescriptionObstacle warningStopped/Skidding/Slowing shovel in vehicle warning, road obstacle/object-on-road warningLane Merge/Lane Change AssistanceMerging/Lane changing vehicles communicates with vehicles in lane to safely and smoothly merge.Adaptive Cruise/Cooperative DrivingAutomatically stop and go smoothly, when vehicles are in heavy roadway traffic cooperates driving by exchanging cruising data among vehicles. crossover/Hidden Driveway conflict precedentvehicles communicates to avoid collisions at intersections without traffic lights or hidden driveway.Roadwa y Condition Awarenessfomites communicates to eliminate vision beyond line of sight (e.g. beyond a big turn or over a hill)Table-1.1 Example of Vehicle Safety Communication 101.3 Scope of ProjectSome of the industries and universities working on VANETs are as followDaimlerChrysler AGFraunhofer FOKUSNEC Europe Ltd.Robert Bosch GmbHSiemens AGTEMIC TelefunkenMicroelectronic GmbHUniversities of Mannheim, Hamburg-Harburg, Karlsruhe, and Hannover.1.4 constitution of ProjectThisthesisis mainly divided into four chapters. In the first two chapters (1-2) introduction and an overview over the topic and go ford technologies is given. In the following chapter (3), we have discussed the standards of IEEE and also discussed the MAC Layer and PHY Layer of IEEE 802.11 in detail. In chapter 4, simulation analysis of our work is shown along with the solutions. In the last chapter, we have summarized this whole thesis, what we have cerebrate from this project and future work needs to be done are d iscussed. Finally, in appendix somewhat additional information can be name. In chapter two, VANETs characteristics, some of its applications and the research challenges faced by governments and car manufactures are discussed, continued by MAC Layer and PHY in chapter three. We have also discussed the cockle computer architecture in chapter 2. From chapter three on, we have a look at some protocol improvements and extensions. Some thoughts, tests and their results on VANETs, those are related to our work, can be found in chapter 4.Chapter 2VANETsVANETs (Vehicle ad-hoc Networks) is a form of Mobile Ad-hoc Networks (MANETs), which provide a communication between the vehicles and also fixed equipments, usually defined as road side equipments.2.1 What is VANETVehicle ad hoc network comprises of three words.i. Vehicleii. Ad-hociii. Networksi. VehicleA machine such as a bus or car for transporting people or goods. 4A lot of progress is happening in the field of vehicles since the invent ion of wheel. Development is receivable to provide services to the people and make their task easier.ii. Ad-hocIt refers to dealing with special situations as they occur rather than functions that are repeated on a regular basis. For example you just meet soul outside your office and you exchange some words. On the other hand infrastructure governing body is a system which is fully installed and deployed than it works according to some predefined rules and regulations.iii. NetworkA system, as in a business or university, consisting of a computer or computers and connected terminals, printers etc. specific, a local study network.3The concept of networking is introduced because resources are limited and we have to utilize them efficiently. As it is not possible for firms to provide printer, faxes and other machines to everyone so they just inter colligate all the devices so that each one can utilize it keeping the cost at minimum.vehicular connectivity can be fairly considered a future killer application, adding extra value to the car industry and operators services. Taking into account the constant growth of automotive market and the increasing demand for the car safety, also driven by regulatory (governmental) domain, the potential of car-to-car connectivity is immense. Such system should be suitable for a wide spectrum of applications, including safety related, traffic and slide by control and entertainment. First, issues concerning architecture, security, routing, cognitive process or QoS need to be investigated. Standardization of interfaces and protocols should be carefully planned to ensure interoperability, as vehicles coming from different vendors must communicate seamlessly. Having different competing systems would result in decreased market penetration and despicable overall system strength, thus only one common system can be deployed. And finally, quick of scent deployment strategy has to be proposed, as most application would become functi onal only after certain market penetration is reached. The first milestone of standardization process was the allocation of 75 MHz of DSRC (Dedicated Short Range Communications) spectrum to accommodate Vehicle-to-Vehicle (V2V) and Vehicle-to- Infrastructure (V2I) communication for safety-related applications by US Federal Communications Commission (1999). Commercial applications are also allowed to operate in this spectrum.2.2 VANETs ApplicationsAccording to the DSRC, there are over one hundred recommended applications of VANETs. These applications are of two categories, safety and non-safety related application. Moreover, they can be categorized into OBU-to-OBU or OBU-to-RSU applications. Some of these applications are as followed2.2.1 Co-operative Collision WarningCo-operative collision warning is an OBU-to-OBU safety application, that is, in case of any abrupt change in speed or driving direction, the vehicle is considered abnormal and broadcasts a warning message to warn all of the following vehicles of the probable danger. This application strikes an efficient broadcasting algorithm with a very small latency.2.2.2 Lane Change WarningLane-change warning is an OBU-to-OBU safety application, that is, a vehicle driver can warn other vehicles of his intention to change the traveling lane and to book an empty room in the glide slope lane. Again, this application depends on broadcasting.2.2.3 production Collision WarningIntersection collision warning is an OBU-to-RSU safety application. At intersections, a centralized node warns come on vehicles of possible accidents and assists them determining the suitable saluteing speed. This application uses only broadcast messages. In June 2007, General Motors GM addressed the previously mentioned applications and announced for the first wireless automated collision avoidance system using vehicle-to-vehicle communication (Figure-2.1), as quoted from GM, If the driver doesnt respond to the alerts, the vehicle can brin g itself to a safe stop by avoiding a collision.2.2.4 Approaching emergency brake vehicleApproaching emergency vehicle is an OBU-to-OBU public-safety application, that is, high-speed emergency vehicles (ambulance or police car) can warn other vehicles to clear their lane. Again, this application depends on broadcasting.2.2.5 Rollover WarningRollover warning is an OBU-to-RSU safety application. A RSU localized at critical curves can broadcast information about curve angle and road condition, so that, approaching vehicles can determine the maximum possible approaching speed before rollover.2.2.6 Work Zone WarningWork zone warning is an OBU-to-RSU safety application. A RSU is mounted in work zones to warn incoming vehicles of the probable danger and warn them to decrease the speed and change the driving lane.2.2.7 Near Term 5Traffic Signal Violation WarningCurve Speed WarningEmergency Electronic Brake Lights2.2.8 Mid Term 5Pre-Crash WarningCooperative Forward Collision WarningLeft Tur n AssistantLane Change WarningStop Sign Movement AssistanceApplicationComm. typeFreqLatency entropy TransmittedRangeTraffic Signal Violation12V One-way, P2M10 Hz100msecSignal Status, Timing, Surface Heading, Light Position, Weather250mCurve Speed Warning12V One-way, P2M1 Hz1000msecCurve Location, Curvature, Speed Limit, Bank, Surface200mEmergency Brake LightVehicle to Vehicle Two-way, P2M10 Hz100msecPosition, Deceleration Heading, Velocity200mPre-Crash SensingVehicle to Vehicle Two-way, P2P50 Hz20msecVehicle type, gawp Rate, Position Heading, Acceleration,50mCollision WarningVehicle to Vehicle One-way, P2M10 Hz100msecVehicle type, Position, Heading Velocity, Acceleration, Yaw Rate150mLeft Turn Assist12V and V21 One-way, P2M10 Hz100msecSignal Status, Timing, Position, Direction, Road Geom., Vehicle Heading300mLane Change WarningVehicle to Vehicle One-way, P2M10 Hz100msecPosition, Heading, Velocity, Acceleration, Turn Signal Status150mStop Sign Assist12V and V21 One-way10 Hz100msecPo sition, Velocity, Heading, Warning300mTable-2.1 Eight high-priority vehicular safety applications as chosen by NHTSA and VSCC. Note that communication freq. ranges from 1-50 Hz and Max. Communication range spam 50-300 meters. P2M represents Point-to-Multipoint, 12V represents infrastructure to vehicle and V21 represents Vehicle-to-Infrastructure. 52.2.9 Comfort related applicationsTraffic efficiencyBetter navigationInternet accessThe whole theme of these applications is improving passengers comfort and traffic efficiency. That includes nearest POI (Points of Interest) localization, current traffic or weather information and interactive communication. All kinds of applications might be applied here. Another application is reception of data from commercial vehicles and roadside infrastructure about their businesses (wireless advertising). Enterprises (shopping malls, fast foods, vaunt stations, hotels) can set up stationary gateways to transmit marketing data to potential customers p assing by.The important feature of comfort/commercial applications is that they should not interpose with safety applications. In this context traffic prioritizing and use of separate physical channels is a viable solution.2.2.10 Safety related applicationsAccidence avoidingDanger warningsIntersection coordinationCooperative drivingSafety-related applications may be grouped in three main classes assistance (navigation, cooperative collision avoidance, and lane-changing), information (speed limit or work zone info) and warning (post crash, obstacle or road condition warnings). They usually demand direct communication due to their delay-critical nature. One such application would be emergency notifications, e.g. emergency braking alarms. In case of an accident or sudden hard breaking, a warning is sent to the subsequent cars. That information could also be propagated by cars driving in the opposite direction and, thereby, conveyed to the vehicles that might run into the accident. Ano ther, more advanced example is cooperative driver assistance system, which exploits the exchange of sensor data or other status information among cars. The basic idea is to broaden the range of perception of the driver beyond his field of vision and further on to assist the driver with assistance applications. Transmitting this data to cars following on the same road, drivers get information about hazards, obstacles or traffic flow ahead hence driving is more efficient and safer. Some applications of this kind are operating only when certain penetration of VANET enabled cars is reached. 62.3 VANETs CharacteristicsAlthough VANETs, Wireless sensing element Networks and Wireless Mesh Networks are special cases of the general MANETs, VANETs possess some noticeable characteristics that make its nature a unique one. These properties present considerable challenges and require a set of new especially designed protocols.Due to the high mobility of vehicles, that can be up to one hundred fi fty kilometers per hour, the topographic anatomy of some(prenominal) VANET changes frequently and un sufferedly. Hence, the time that a communication link exists between two vehicles is very short especially when the vehicles are traveling in opposite directions. A one solution to increase the lifetime of links is to increase the transmission power, but increasing a vehicles transmission range will increase the collision probability and mortify the overall throughput of the system. The other solution having a set of new protocols is employing a very low latency.Another effect of these high speed nodes is that the usefulness of the broadcasted messages is very critical to latency. For example, if we assume that a vehicle is unexpectedly stopping or suddenly stops, it should broadcast a message to warn other vehicles of the probable danger. Considering that the driver needs at to the lowest degree 0.70 to 0.75 sec to initiate his response 7, the warning message should be delivered a t virtually zero sec latency.In VANETs, location of nodes changes very quickly and unpredictably, so that, building an efficient routing table or a list of neighbor nodes will tire out the wireless channel and reduce the network efficiency. Protocols that rely on prior information about location of nodes are likely to have a poor performance.However, the topologies of a VANET can be a benefit because vehicles are not expected to leave the covered road therefore, the running direction of vehicles is predictable to some extent.Although, the design challenge of protocols in wireless sensor networks is to minimize the power consumption, this is not a problem in VANETs. Nodes in VANETs depend on a good power supply (e.g. vehicle battery and the dynamo) and the required transmission power is small compared with power consumption of on-board facilities (e.g. air-condition).It is predicted that, as VANET is deployed in the beginning, only a small percentage of vehicles will be outfitted wit h transceivers. Thus, the benefits of the new technology, especially OBU-to-OBU applications, will not go up until many years. Furthermore, the limited number of vehicles with transceivers will lead to a numerous fragmentation of the network. Even when VANET is fully deployed, fragmentation may still exist in rural areas, thereupon, any VANET protocol should expect a fragmented network.Privacy, safety and security are of fundamental effect on the public receiving of this technology. In VANETs, every node represents a specific soulfulness and its location tells about his location.Any requirement of privacy can ease a third party monitoring persons daily activities. However, from the other point of view, high authorities should gain access to identity information to ensure punishment of illegal actions, where, there is a fear of a possible misuse of this feature. The mon discern with messages could increase false alarms and accidents in some situations defeating the whole purpose of this technology.Finally, the key difference between VANET protocols and any other form of Ad-Hoc networks is the design requirement. In VANETs, the key design requirement is to minimize latency with no prior topology information. However, the key design requirement of Wireless Sensor Network is to maintain network connectivity with the minimum power consumption and the key proposed design requirement of Wireless Mesh Network is reliability.WE can summarize the main characteristics of VANETs as followsHigh mobility of nodesNo prior information about the exact location of neighbor nodesPredictable topology (to some extent)Significant latency requirement especially in cases of safety related applicationsNo problem with powerSlow migration rateHigh possibility to be fragmentedCrucial effect of security and privacy2.4 Research Challenges in VANETsWhen deploying of a vehicular networking system, a number of issues have to be determined, often from distant fields of expertise, ranging f rom applications improvement up to efficient issues. VANET could be considered as an instantiation of MANETs (Mobile Ad hoc Networks) however their behavior is fundamentally different. These unique characteristics of these networks are as followsRapid topology changes and fragmentation, resulting in small effective network diameter close to no power constrainsVariable, highly dynamic scale and network densityDriver might adjust his behavior reacting to the data received from the network, inflicting a topology changeHere we briefly mention some of the core research challenges that need to be discussed.2.5 Wireless Access technologyThere are several(prenominal) wireless access standards that could be used as a foundation for VANET technology. In general the major seek is to provide a set of air interface protocols and parameters for high-speed vehicular communication by mean of one or more different media.2.5.1 Cellular technology (2/2.5/3G)The key role of 2/2.5G i.e. cellular technol ogy are coverage and security, and 3G, slowly but steadily coming over 2/2,5G, provides enhanced and better capacity and bandwidth. Several telematic and fleet management projects already uses cellular technology (e.g. SMS reports), on the other hand it is comparatively more expensive, together with limited bandwidth and latency make it impossible to use as a main communication means.2.5.2 IEEE 802.11p based technologyIEEE is working on a variation of 802.11 standards that would be applied to support communication between vehicles and the roadside, or, alternatively, among vehicles themselves, operating at speeds up to 200 km/h, handling communication ranges as high as 1,000 meters. PHY and MAC layers are based on IEEE 802.11a, shifted to the 5.9 GHz band (5.850-5.925 GHz within US). The technology is promoted by the car industry both in Europe and US. Estimated deployment cost is foreseen to be relatively low due to large production volumes. C. Combined wireless access one of the m ost significant and important efforts in combining those wireless access technologies is done by ISO TC 204 WG16. It builds on the top of IEEE 802.11p, using additional set of interface protocols. Currently supported standards include Cellular Systems GSM/GPRS (2/2.5G) and UMTS (3G), Infrared Communication and wireless systems in 60 GHz band. Using all those interfaces in a single, uniform system would result in increased flexibility and redundancy, thus improving applications performance. aside from interoperability issues, CALM is also engaged in the standardization of the protocols, network layer and the management services.2.6 wheel Architecture flutter system architecture is totally a set of WAVE standards that describes the communication stack of vehicular nodes and the physical air link between them. Any RSU may have two interfaces, one for the WAVE stack or architecture or wireless networks and the other for external interfaces like wired line Ethernet that may be used to g et access to internet and for connection to internet it is mainly used. Similarly, each OBU may have two interfaces, one for the wireless WAVE stack and the other for sensor-connections and human interaction.OBU is not full-duplex so, therefore, it cannot transmit messages simultaneously, so DSRC is half-duplex. The RSU and OBU can send messages only when the channel becomes idle and also confirmed that it is idle. If the channel is busy, RSU and OBU need to wait and if the channel is idle then RSU or OBU will send the signal Request to Send (RTS) to control channel. The control channel will allocate the channel on the basis of high priority first followed by low priority. The high priority messages are those messages related to public safety.The WAVE architecture is defined by the IEEE 1609 family of standards and uses the IEEE 802.11p amendment to extend the use of 802.11 to vehicles. The IEEE 1609 family is composed of four standards describing the resource manager, security serv ices, networking services and multi- channel operations.WAVE standard consists of five complementary parts802.11p Wireless Access in Vehicular Environments (WAVE) 8 which is an amendment to the well known IEEE 802.11 Wireless LAN Standard and covers the physical layer of the system.1609.1 option conductor 8 that covers optional recommendations for the application layer. 13, 141609.2 Security run for Applications and Management Messages 8 that covers security, dependable message formatting, processing and exchange. 13, 141609.3 Networking Services 8 that covers the WAVE communication stack. 13, 141609.4 Multi-Channel Operation 8 that covers the arrangement of multiple channels and how they should be used. 13, 14The most evident part is its dual stack. Whereas there is a well-known stack, called TCP/IP stacks and on the other hand there is a stack, called WAVE Short Message stack. The function of the WAVE Short Message stack is to provide a connectionless transport protocol i.e. wi thout checking the connection that whether connection is made or not, similar to UDP but on a single-hop basis. The safety applications are supposed to use this stack only while non-safety applications can use both. It should be noted that the devise or design of this approach is focused on non-safety applications and considers safety as a black box.2.6.1 IEEE 1609.1 Resource ManagerThe IEEE 1609.1 standard defines the architecture and data flows of WAVE. It also describes command messages and data formats. 9, 8. The standard explains how data communication between road side units and vehicle on board units occurs. The discussion of this standards operation will be based on the standard defines applications residing on the on board unit as Resource Command Processors and those residing in road side units or elsewhere as Resource Manager Applications. The Resource Manager is the focus of this standard and is also the application that is responsible for managing communication between multiple Resource Manager Applications and Resource Command Processors. 9, 8WAVE communication imitates a client-server architecture that is managed by the Resource Manager. For example, in the case where a company wants to provide traffic updates by analyzing vehicle speed statistics in a stretch of highway, the application that analyzes the traffic data (a Resource Manager Application) would reside on the road side unit or a outside(a) server that is connected to a road side unit. When the Resource Manager Application sends a request for the speed of the vehicle the Resource Manager application in the road side unit receives the request then forwards it to the vehicles Resource Command Processor application using WAVE. The vehicle then replies to the Resource Manager which forwards the message to the Resource Manager Application. If another passing vehicle asks for traffic updates by sending a request to the road side unit, the roles of client and server from the previous case a re switched.WAVE is designed to provide secure communications and minimize the cost of on board units by minimizing the amount of processing required by them. All only desired information relevant to road safety will be transferred.2.6.2 IEEE 1609.2 Security ServicesThe IEEE 1609.2 standard defines secure message formats and processing and infers circumstances for using secure message exchange. 13, 8. It deals with security services for applications and management messages. Security is important in WAVE because vehicles transmit sensitive information that could constitute a violation of privacy if accessed by unauthorized parties. The efficacy and reliability of a system where information is self-possessed and shared among autonomous entities raises concerns about the authenticity of the received data. For example, a bad actor could misrepresent its observations in order to gain advantage (e.g. a vehicle V falsely reports that its desired road R is stopped with traffic, thereby en couraging others to avoid R and providing a less-congested trip for V on R). More malicious actors could impersonate other vehicles or road-side infrastructure in order to trigger safety hazards. Vehicles could reduce this threat by creating networks of trust, and ignoring, or at least distrusting, information from un-trusted senders. 13, 8A trusted communication generally requires two properties are metThe sender is conclusively identified as a trusted source.While in transit, the contents of the senders message are not tampered.WAVE maintains security by ensuring confidentiality and authenticity in message transmissions. The final standard is expected to address privacy issues with the current version. WAVE ensures confidentiality