The scope of the present document is to define the two lowest layers, physical layer and the data link layer, grouped into the access layer of the ITS station reference architecture EN 302 665 [i.8]. The access layer technology that is specified in the present document is collectively called ITS-G5. It is part of the communication stack supporting data exchange between mobile stations without prior network set-up, i.e. ad hoc mode, for the following frequency bands in Europe:
- ITS-G5A: Operation of ITS-G5 in European ITS frequency bands dedicated to ITS for safety related applications in the frequency range 5,875 GHz to 5,905 GHz.
- ITS-G5B: Operation in European ITS frequency bands dedicated to ITS non-safety applications in the frequency range 5,855 GHz to 5,875 GHz.
- ITS-G5D: Operation of ITS applications in the frequency range 5,905 GHz to 5,925 GHz.
The ITS-G5 technology is based on IEEE 802.11-2012 [3] and IEEE/ISO/IEC 8802-2-1998 [5]. By setting the MIB variable dot11OCBActivated to true in IEEE 802.11-2012 [3] communication outside the context of a BSS is possible. This type of communication allows for immediate exchange of data frames, avoiding the management overhead used with the establishment of a network. All requirements in IEEE 802.11-2012 [3] associated with communication "outside the context of a BSS" are also requirements in the present document. All optional functionality in IEEE 802.11-2012 [3] associated with communication "outside the context of a BSS" is also optional in the present document.