Publisher Summary This chapter reveals that the video signal transmission is a key component in any closed circuit television (CCTV) installation. Successful installation requires a good understanding of transmission systems. Most systems use coaxial cable, but fiber-optic cable is gaining acceptance because of its better picture quality and lower risk factor with respect to ground loops and electrical interference. In special situations where coaxial or fiber-optic cable is inappropriate, other wired or wireless means such as radio frequency (RF), microwave, or light-wave transmission are used. For very long-range applications, non-real-time slow-scan systems are appropriate. Many security system designers consider cabling to be less important than choosing the camera, lens, and other monitoring equipment in a CCTV application. They often attempt to cut costs on cabling equipment and installation time, since they often make up a large fraction of the total system cost. Such equipment is not visible and can seem like an unimportant accessory. However, such cost-cutting can drastically weaken the overall system performance and picture quality.