This International Standard selects the options appropriate for CALM using mobile wireless broadband (MWB) techniques conforming to ATIS 0700004-2005 (HC-SDMA) air interface and protocol specification recommended by ITU-R M.1801 and specifies the management interface requirements. CALM links are required for quasi-continuous, prolonged and short communications between vehicles and the roadside, between vehicles, and between mobile equipment and fixed infrastructure points. Wherever practicable, this International Standard has been developed by reference to suitable extant standards, adopted by selection. Required regional variations are provided. Application specific upper layers will not be included in this International Standard, but will be driven by application standards (which might not be technology specific).