A design of interactive video service system in telecommunication network

• Main Authors: Youchuan Chang, 張有泉
• Other Authors: Ling-Hwei Chen
• Format: Others
• Language: zh-TW
• Published: 1994
• Online Access: http://ndltd.ncl.edu.tw/handle/00832146299024310692

碩士 === 國立交通大學 === 資訊科學學系 === 82 === An interactive video information service system is implemented to study the feasibility of providing interactive video services over the existing telephone subscriber lines. Thisim plementation applies the ADSL (asymmetric digital subscriber lines) technology to enhance the traditional copper twisted pair wires to simultaneously provide a one-way high bit rate channel of 1.544Mbps, a bidirectional control channel of 9.6Kbps and the original POTS (plain old telephone system) line. Applying the MPEG technology, the supplier's audio and video information density (Megabit per second) is compressed to 1.5Mbps. Audio and video information of this density can be reconstructed with a quality comparable to VHS. The ADSL transmission technology and the MPEG compression technology together make providing interactive video service over the existing telephone subscriber lines feasible. In the implemented system, a FDDI network is used as the video server backbone of the central office. All video servers and the network manager are connected over the FDDI network and thus compose a video server system capable of providing 32 sets of program to 450 subscribers. The implemented system provides all control functions of VCR such as PLAY, FAST FORWARD, FAST BACKWORD, PAUSE and SLOW PLAY; in addition, the display area can be proportoinally readjusted. While pausing and forwarding, the advantage of digital signal processing renders a better video quality than the traditional analog VCR.