(A system that terminates multimedia communication is called a multimedia communication system. Multimedia communication refers to a communication method that can provide a variety of media information, such as motion, image, graphics, data, text, etc., together in the communication process. Compared with traditional single-media communication such as telephone, telegram, fax, and text data transmission, users of multimedia communication can not only exchange information with audio, video, and text, but also have complete knowledge of the entire communication process.)