High quality video-on-demand services using Asymmetrical Digital Subscriber Line technology on Hong Kong telephone network
Liou, Ming L.
Au, Oscar C.
Murch, Ross David
Tsang, Danny H.K.
Yau, Sze Fong
|Source||Hong Kong Telecom Institute of Information Technology Project Report , HKTIIT93/94.EG03|
|Summary||The objective of this proposal is to conduct a full scale study of implementing a high quality video-on-demand (VOD) service using the Asymmetrical Digital Subscription Line (ADSL) technology on the Hong Kong telephone network. ADSL is a digital transport technology pioneered by Bellcore researchers with an objective of providing digital subscriber line services on existing copper loops . The term asymmetrical implies that information traffic from one side (normally the central office) to the other side (the subscriber) is much heavier than the other way around. The loop has to be unloaded in order to achieve high bit rate. Researchers at Bellcore have empirically demonstrated that with ADSL, the bit rate can easily achieve the T1 rate (1.544 megabit/sec) on most existing unloaded copper loops. And by restricting the loop lengths and gauge size, the bit rate can go up to more than 9 megabit/sec . By adapting video and audio compression schemes, the transport rate of ADSL service is adequate for the delivery of high quality video services and multimedia applications . These high bit rate is achieved by the utilization of advance digital signal processing methodologies in channel equalization, echo canceling, waveform shaping, without requiring customized engineering or extensive reinforcement of the old plants. Thus, broadband services can be provided at affordable price to subscribers. This certainly increase the asset value of the existing loops. In future development, ADSL can be combined with fiber loops in a fiber-to-the-curb and copper-to-the-home setting to provide even higher quality broadband services. This combination should fit well into the Hong Kong's high inhabiting density environment.|
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