# Review of V2X-IoT Standards and Frameworks for ITS Applications
## 2 Core ITS Standards
### Standards for Dedicated Short-Range Communications (DSRC) Technology  
Dedicated Short-Range Communication (DSRC) technologies are designed for vehicles using short-range wireless radio, for data exchange between vehicles and roadside infrastructure. Both the DSRC term and abbreviation are associated with the 1998 US Federal Communications Commission (FCC) initiative to conclude a regulation for (5.850-5.925) GHz band allocation [23]. Later, with the rapid development of ITS, this term/abbreviation has been increasingly used ever more widely. Figure 1 shows DSRC frequency bands for ITS in North America, Europe and Japan. Let us consider these spectrum bands and the standards that describe them in more detail. The International Telecommunication Union (ITU) has developed a number of key recommendations for ITS systems: ITU-R M.1452 [24] and ITU-R M.1453 [25]. The ITU-R M.1452 recommendation specifies system requirements and operational characteristics for millimeter  
Figure 1: Frequency spectrum bands for Dedicated Short-Range Communications in North America, Europe and Japan. wave radiocommunication systems. The recommendation covers vehicular collision avoidance radars operating in the (76-77) GHz and (77-81) GHz bands and integrated millimeter wave radiocommunication systems for ITS in (57-66) GHz range for V2V and V2I. The ITU-R M.1452 recommendation frequency spectrum bands are not shown in Figure 1. Meanwhile, according to the ITU-R M.1453 recommendation, ITS distinguishes the (5.725-5.875) GHz band and describes two methods for DSRC technologies: active (transceiver) or backscatter (transponder). Two sections of the DSRC frequency spectrum can be distinguished in North America: (902-928) MHz and (5.850-5.925) GHz. The last band, with a width of 75 MHz, was introduced in October 1999 by the US Federal Communications Commission (FCC). This frequency band was dedicated to a wide range of DSRC communications ITS applications: traffic light management, traffic monitoring, passenger alerting, automatic toll collection, traffic congestion detection and other areas [26]. In 2010, IEEE (Institute of Electrical and Electronics Engineers) completed the development of an improved edition of the IEEE 802.11 protocol, called IEEE 802.11p [27]. The main purpose of this standard was to describe the physical (PHY) and Medium Access Control (MAC) layers for interchanging wireless broadcast messages in a vehicular environment. The IEEE 802.11p standard is based on the IEEE 1609 family of standards for wireless access in vehicular environments, also known as WAVE [28]. As mentioned earlier, this standard allocates the 75 MHz bandwidth at the (5.850-5.925) GHz frequency band, divided into seven channels of 10 MHz, one for the control channel, and the other six reserved for service channels. Meanwhile, the (5.850-5.855) GHz band is reserved for the future uses. American Society for Testing and Material (ASTM) regulates the physical (PHY) layer description and developed the ASTM E2158-01 standard specification for the North American 902 MHz to 928 MHz frequency band [29]. This band is used for electronic toll collection, commercial and non-commercial vehicle applications. The ASTM E2158-01 standard is not compatible with the above-mentioned IEEE 802.11p DSRC standard. Three frequency spectrum bands for ITS could be distinguished in Europe: (5.470-5.725) GHz, (5.795-5.815) GHz and (5.855-5.925) GHz. The physical (PHY) and medium access control (MAC) layers of the first and third frequency bands mentioned above are regulated by European Telecommunications Standards Institute (ETSI) standard ETSI ES 202 663 [30].