# Review of V2X-IoT Standards and Frameworks for ITS Applications
## 1 Introduction
A common term that combines all these types of communication, providing vehicle links with various recipients, is called vehicle-to-everything (V2X). The already mentioned \"Road Safety Program 2011-2020\" [5] states, that one of the seven strategic goals is to boost smart technology in order to enable data and information exchange between vehicles, pedestrians and inter-roadside infrastructure (for example, to receive real-time information on speed limits, traffic flows, traffic jams, pedestrians on road, etc.). As a result, the EU encourages both research institutions and business companies to develop new ITSs, to carry out their deployment, research and further development by allocating investments from different funds. The use of V2X communications, along with the existing possibilities of modern vehicles, could not only solve the abovementioned issues but would also offer better quality public transport services, better road quality, more efficient logistics solutions, efficient use of transport infrastructure, especially accurate electronic maps, various vehicle manufacturers and vehicles services, and many other, relevant and innovative solutions and services. Some examples of such future services are provided by CAR2 CAR Communication Consortium (a consortium of major car manufacturers), in their published manifesto: various safety warnings, improved and complete route guidance and navigation, green light optimal speed recommendation, V2V merging assistance, Internet access in vehicles, informing the driver of relevant and important issues, remote diagnostics of vehicles and many others [8]. There are currently two data transfer technologies that can be used in V2X systems: dedicated short-range communications (DSRC) technology and cellular vehicle-to-everything (C-V2X) communication technologies. The DSRC technologies are used for data transfer between vehicles, inter-roadside infrastructure and pedestrians when its distance is limited to a few hundred meters. Data exchange is carried out between devices installed in DSRC communication system vehicles,called on board units (OBU), and roadside equipped devices, called road side units (RSU), as well as pedestrians' portable mobile devices. Many world governments are currently supporting and investing in the deployment and research of DSRC's communication technologies. For example, in 2016 the US Department of Transportation (DOT) announced that it will invest USD 45 million into three DSRC technology pilot projects, in accordance with the Connected Vehicle Pilot Deployment Program. The aim of the program is to promote V2X innovation by combining research and practical engineering solutions. For example, New York City's Department of Transportation has planned to introduce V2V technological solutions to 8000 city-owned vehicles and V2I technological solutions in several streets of Manhattan and Brooklyn as a part of this pilot project [9]. Another example, this time in Europe, in September 2014 the Collective Transport Society of Porto (Portugal) and the municipality of Porto started offering free Wi-Fi service to their passengers in the city. Over 600 vehicles, including entire public bus fleet, taxis and municipal service vehicles have been equipped with OBUs and routers that transmit and receive Internet data via one of two possible data paths [10]. Priority is given to DSRC communication technology, which has 55 access points/RSUs (April 2016 data) in different parts of the city that connect directly or via multiple buses OBUs. If data transfer via DSRC is not available, the data are transferred over via cellular Long Term Evolution (LTE) networks. However, a lot of published research data have shown that DSRC technologies face reliability, efficiency, and productivity problems with high traffic volumes. Furthermore, DSRC communication technologies are not designed to transfer large amounts of data and access the Internet in vehicles.