Vehicle-to-vehicle (V2V) is an automobile technology designed to allow automobiles to "talk" to each other. V2V communications form a wireless ad hoc network on the roads. Such networks are also referred to as vehicular ad hoc networks, VANETs. The systems will use a region of the 5.9 GHz band set aside by the United States Congress, the unlicensed frequency also used by WiFi. The US V2V standard, commonly known as WAVE ("Wireless Access for Vehicular Environments"), builds upon the lower-level IEEE 802.11p standard, as early as 2004.
For Europe Commission Decision 2008/671/EC harmonises the use of the 5 875-5 905 MHz frequency band for transport safety ITS applications. In Europe V2V is standardised as ETSI ITS-G5, a standard also based on IEEE 802.11p. C-ITS, cooperative ITS, is also a term used in EU policy making, closely linked to ITS-G5 and V2V.
V2V is also known as VANET (vehicular ad hoc network). It is a variation of MANET (Mobile ad hoc network), with the emphasis being now the node is the vehicle. In 2001, it was mentioned in a publication that ad hoc networks can be formed by cars and such networks can help overcome blind spots, avoid accidents, etc. The infrastructure also participates in such systems, then referred to as V2X (vehicle-to-everything). Over the years, there have been considerable research and projects in this area, applying VANETs for a variety of applications, ranging from safety to navigation and law enforcement.
In 1999 the US Federal Communications Commission (FCC) allocated 75 MHz in the spectrum of 5.850-5.925 GHz for intelligent transport systems.
Conflict over spectrum
As of 2016, V2V is under threat from cable television and other tech firms that want to take away a big chunk of the radio spectrum currently reserved for it and use those frequencies for high-speed internet service. V2V's current share of spectrum was set aside by the government in 1999. The auto industry is trying to retain all it can saying that it desperately needs the spectrum for V2V. The Federal Communications Commission has taken the side of the tech companies with the National Traffic Safety Board supporting the position of the auto industry. Internet service providers who want the spectrum claim that self-driving cars will make extensive use of V2V unnecessary. The auto industry said it is willing to share the spectrum if V2V service is not slowed or disrupted; the FCC plans to test several sharing schemes.
Research in VANETs started as early as 2000, in universities and research labs, having evolved from researchers working on wireless ad hoc networks. Many have worked on media access protocols, routing, warning message dissemination, and VANET application scenarios. V2V is currently in active development by General Motors, which demonstrated the system in 2006 using Cadillac vehicles. Other automakers working on V2V include Toyota, BMW, Daimler, Honda, Audi, Volvo and the Car-to-Car communication consortium.
Since then the United States Department of Transportation (USDOT) has been working with a range of stakeholders on V2X. In 2012 a pre-deployment project was implemented in Ann Arbor, Michigan. 2800 vehicles covering cars, motorcycles, buses and HGV of different brands took part using equipment by different manufacturers. The US National Highway Traffic Safety Administration (NHTSA) saw this model deployment as proof that road safety could be improved and that WAVE standard technology was interoperable. In August 2014 NHTSA published a report arguing vehicle-to-vehicle technology was technically proven as ready for deployment. In April 2014 it was reported that U.S. regulators were close to approving V2V standards for the U.S. market. On 20 August 2014 the NHTSA published an Advance Notice of Proposed Rulemaking (ANPRM) in the Federal Register, arguing that the safety benefits of V2X communication could only be achieved, if a significant part of the vehicles fleet was equipped. Because of the lacking immediate benefit for early adopters the NHTSA proposed a mandatory introduction. On 25 June 2015 the US House of Representatives held a hearing on the matter, where again the NHTSA, as well as other stakeholders argued the case for V2X.
In the EU the ITS Directive 2010/40/EU was adopted in 2010. It aims to assure that ITS applications are interoperable and can operate across national borders, it defines priority areas for secondary legislation, which cover V2X and requires technologies to be mature. In 2014 the European Commission's industry stakeholder "C-ITS Deployment Platform" started working on a regulatory framework for V2X in the EU. It identified key approaches to an EU-wide V2X security Public Key infrastructure (PKI) and data protection, as well as facilitating a mitigation standard to prevent radio interference between ITS-G5 based V2X and CEN DSRC-based road charging systems. The European Commission recognised ITS-G5 as the initial communication technology in its 5G Action Plan and the accompanying explanatory document, to form a communication environment consisting of ITS-G5 and cellular communication as envisioned by EU Member States. Various pre-deployment projects exist at EU or EU Member State level, such as SCOOP@F, the Testfeld Telematik, the digital testbed Autobahn, the Rotterdam-Vienna ITS Corridor, Nordic Way, COMPASS4D or C-ROADS. Further projects are under preparation.
- Connected car
- Vehicular communication systems
- V2X (vehicle-to-everything)
- wireless ad hoc network
- mobile ad hoc network
- Commission Decision 2008/671/EC "on the harmonised use of radio spectrum in the 5 875-5 905 MHz frequency band for safety-related applications of Intelligent Transport Systems (ITS)" (http://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A32008D0671)
- EN 302 663 Intelligent Transport Systems (ITS); Access layer specification for Intelligent Transport Systems operating in the 5 GHz frequency band (http://www.etsi.org/deliver/etsi_en/302600_302699/302663/01.02.00_20/en_302663v010200a.pdf)
- Chai K Toh (2001). Ad Hoc Mobile Wireless Networks: Protocols and Systems. Pearson Education. ISBN 9780132442046.
- CORPORATION., TOYOTA MOTOR. "Toyota to Bring Vehicle-Infrastructure Cooperative Systems to New Models in 2015 | TOYOTA Global Newsroom". newsroom.toyota.co.jp. Retrieved 2016-06-01.
- "Car 2 Car - Communication Consortium: Technical Approach". www.car-to-car.org. Retrieved 2016-06-01.
- Safety Pilot Model Deployment Technical Fact Sheet (http://www.safercar.gov/staticfiles/safercar/connected/Technical_Fact_Sheet-Model_Deployment.pdf)
- NHTSA: Vehicle-to-Vehicle Communications: Readiness of V2V Technology for Application (http://www.nhtsa.gov/staticfiles/rulemaking/pdf/V2V/Readiness-of-V2V-Technology-for-Application-812014.pdf)
- "Vehicles May Soon Be Talking to Each Other". VOA. Retrieved 2016-06-01.
- Federal Motor Vehicle Safety Standards: Vehicle-to-Vehicle (V2V) Communications, Docket No. NHTSA–2014–0022 (http://www.nhtsa.gov/staticfiles/rulemaking/pdf/V2V/V2V-ANPRM_081514.pdf)
- Hearing in the House of Representatives (Protocol) (https://energycommerce.house.gov/hearings-and-votes/hearings/vehicle-vehicle-communications-and-connected-roadways-future)
-  Directive 2010/40/EU on the framework for the deployment of Intelligent Transport Systems in the field of road transport and for interfaces with other modes of transport (http://eur-lex.europa.eu/legal-content/EN/ALL/?uri=CELEX%3A32010L0040)
-  C-ITS Deployment Platform – Final Report, January 2016 (http://ec.europa.eu/transport/themes/its/doc/c-its-platform-final-report-january-2016.pdf)
- Intelligent Transport Systems (ITS); Mitigation techniques to avoid interference between European CEN Dedicated Short Range Communication (CEN DSRC) equipment and Intelligent Transport Systems (ITS) operating in the 5 GHz frequency range (http://www.etsi.org/deliver/etsi_ts/102700_102799/102792/01.02.01_60/ts_102792v010201p.pdf)
-  5G for Europe: An Action Plan – COM (2016) 588, footnote 29 (http://ec.europa.eu/newsroom/dae/document.cfm?doc_id=17131)
- 5G Global Developments – SWD (2016) 306, page 9 (http://ec.europa.eu/newsroom/dae/document.cfm?doc_id=17132)
- Amsterdam Declaration – Cooperation in the field of connected and automated driving (https://english.eu2016.nl/binaries/eu2016-en/documents/publications/2016/04/14/declaration-of-amsterdam/2016-04-08-declaration-of-amsterdam-final-format-3.pdf)
- For C-ROADS see: Connecting Europe Facility – Transport 2015 Call for Proposals – Proposal for the Selection of Projects, pages 119-127 (https://ec.europa.eu/inea/sites/inea/files/20160712_cef_tran_brochure_web.pdf)