(With the development of computer network technology and the huge social impact it brings, network communication has become a hot spot of social attention. Network communication from technology to use is not only the Internet, but also includes mobile communication, the digitization of traditional communication networks (such as radio and television networks, cable TV networks) and the digitization of traditional media. This book absorbs the research results communicated by the relevant networks of communication researchers at home and abroad since the 1990s, and combines the research results.)