In the past decade, we have seen the growth of Internet and the growth of the mobile communications. This success is due to the hardware component evolution allowing the deployment of those technologies at a reasonable cost for the user. The focus has been on physical layer and, thanks to hardware component evolution, modems, WLAN boards or mobile phones are available at always more reasonable costs. In parallel, audio and video coders have leveraged the available CPU power to offer better compression and quality allowing the audio and video digital market success. In CCTV world exists the same evolution but as it concerns the security, requirements are more strict and so, new technologies are coming slowly. A lot of systems are still full analogue systems, but digital storage and video over IP is taking more and more place. Trend is full digital CCTV system. After a short overview of video surveillance systems, the work and concepts developed in the European IST project name WCAM (Wireless Cameras and Audio-visual seamless networking) are presented. This project focuses on the technology convergence between video surveillance and multimedia distribution over the Internet.
