1.1 This specification describes a medium access control (MAC) and physical layer (PHY) specification for wireless connectivity using dedicated short-range communications (DSRC) services. This standard is based on and refers to IEEE Standards 802.11, Wireless LAN Medium Access Control and Physical Layer Specifications, and 802.11a, Wireless LAN Medium Access Control and Physical Layer Specifications High-Speed Physical Layer in the 5 GHz Band, with permission from the IEEE society. This specification is meant to be an extension of IEEE 802.11 technology into the high-speed vehicle environment. As presented here, this specification contains just enough information to explain the difference between IEEE 802.11 and IEEE 802.11a operating parameters required to implement a mostly high-speed data transfer service in the 5.9-GHz Intelligent Transportation Systems Radio Service (ITS-RS) Band. Potential operations within the Unlicensed National Information Infrastructure (UNII) Band are also addressed, as appropriate.
1.2 Purpose—The purpose of this specification is to provide wireless communications over short distances between information sources and transactions stations on the roadside and mobile radio units, between mobile units, and between portable units and mobile units. The communications generally occur over line-of-sight distances of less than 1000 m between roadside units and mostly high speed, but occasionally stopped and slow moving, vehicles or between high-speed vehicles. This specification also offers regulatory bodies a means of standardizing access to the 5.9 GHz frequency band for the purpose of interoperable communications to and between vehicles at line-of-sight distances on the roadway.
1.3 Specifically, this specification accomplishes the following:
1.3.1 Describes the functions and services required by a DSRC and IEEE 802.11 compliant device to operate in a high-speed mobile environment.
1.3.2 Refers to IEEE 802.11 MAC procedures.
1.3.3 Defines the 5.9 GHz DSRC signaling technique and interface functions that are controlled by the IEEE 802.11 MAC.
1.3.4 Permits the operation of a DSRC conformant device within a DSRC communications zone that may coexist with multiple overlapping DSRC communication zones.
1.3.5 Describes the requirements and procedures to provide privacy of user information being transferred over the wireless medium and authentication of the DSRC or IEEE 802.11 conformant devices.