Abstract.A number of standards addresses the problem of high-speed data transmission on serial or serial-parallel data lines. Serial-parallel data transmission means the transmitted information is distributed on parallel data lines. Even though several standards exist, there are only a few basic techniques used in most of these standards. This paper is giving an overview of these different basic techniques used in the physical layer of today's data transmission standards, for example DVI/HDMI, USB2.0, Infiniband, SFI5, etc. [1][2][3][4][5][6][7][8][9]. The main focus lies on the approaches used for physical signaling, line coding and information synchronization in serial and serialparallel systems. In addition, currently discussed techniques to improve data transmission in the future will be presented.