C2X communications overview

Mobile communications is usually understood as phoning while moving, with the link via a base station. The success of mobile communications stimulated the idea of direct mobile to mobile communications in and with vehicles. In the last few years regulation authorities made the necessary spectrum in the 5.9 GHz frequency range available and set up preliminary rules. These are the basis for R&D in this wide area. In this paper the basic ideas and primarily the communications channel are discussed.