# Review of V2X-IoT Standards and Frameworks for ITS Applications
## 4 IoT Standards Applicability in ITS  
The Internet of Things (IoT) technology is currently one of the newest and fastest developing directions of information and communication technologies. As evidenced by the global experience of the IoT application and recent research, the scale of services and applications of these technologies in everyday life and business in recent years is steadily increasing and will only increase in the future [90; 91]. The International Data Corporation (IDC), an international information technology market research firm, and the European Commission state that \"the IoT enables objects sharing information with other objects/members in the network, recognizing events and changes so to react autonomously in an appropriate manner. The IoT therefore builds on communication between things (machines, buildings, cars, animals, etc.) that leads to action and value creation\" [92]. Meanwhile, the International Telecommunication Union (ITU) defines the IoT as \"a global infrastructure for the information society, enabling advanced services by interconnecting things based on existing and evolving interoperable information and communication technologies\" [93]. The research focuses on five major domains that already apply or will apply the IoT technologies: health, living, industry, environment, and transport [90]. The IoT technologies, along with a variety of sensors and image recognition and analysis systems, are already widely used and researched in ITS: identifying and planning traffic flows, analyzing and informing on road events, increasing traffic safety, and so on. Various software and hardware Internet platforms are also being developed to assist the driver. For example, the work [94] integrates methods of combining data from former routes, sensors, image recognition and analysis to identify pedestrians and other transport systems on the road. The work [95] provides a cloud-based smart parking system that analyzes and interprets existing geographic location, car parking facilities, traffic flow and parking space reservation information. Many different protocols have been developed for the IoT technologies, which are regulated by various organizations such as IEEE, IETF (Internet Engineering Task Force), ITU, 3 GPP or various alliances such as Zigbee, LoRa and others. Many of these protocols are already standardized, some are still under development, and some are already patented. Standards in the market that regulate protocols in different frequency bands are intended for short or long data transmission distances, various data rates, power consumption, and so on. As a result, a large number of standards and protocols make it difficult to combine different IoT systems and their further development. The most common wireless standards in the IoT technologies are the following: Zigbee, LoRaWAN, LTE-M and NB-IoT, IEEE 802.11 ah (HaLow) and 802.11 af (White-Fi) [96]. The Zigbee standard operates in the unlicensed 2.4 GHz, 915 MHz and 868 MHz bands, and describes wireless network protocols for low-power networked nodes. This standard specifies network and application levels based on the fact that the data channel and the physical layer are developed according to the IEEE 802.15.4 standard. The IoT networks based on this standard are used in systems with low data rates (up to 250 kb/s), the operating distance between nodes is up to 10 m. However, it can work up to 100 m if a lower data rate is used. The Zigbee standard is widely used in intelligent transport systems. For example, in the EMMA (Embedded Middleware in Mobility Applications) project, funded by the European Commission, which involved car and component manufacturers, transport service providers and research institutes, communication between the in-vehicle nodes, cars and road infrastructure was implemented on the Zigbee [97]. There are also more scientific, engineering and practically implemented works that demonstrate the applicability of the Zigbee to intelligent transport systems [98; 99; 100].