A possible ADSL system is illustrated in figure
[1, p. 3,]. A flexible way to connect various servers to
corresponding application's device is to use ATM-switches. Local
ATM-switch is connected to an access module in a telephone central
office. The access module is used to connect the ATM network to
phone-lines. In the access module ATM data stream from server is
decomposed and routed to the corresponding phone-lines.
Figure: ADSL System Architecture
There is a large number of different kind of servers that can be
accessed by an ADSL system. Those servers shown in
figure
are not only future but also today's
technology.
An employee using a work-at-home-server can take full advantage of the high-speed capabilities of an ADSL-system in many ways, e.g., running licensed software, downloading CAD, documents etc.
Video-on-Demand-service is one of the most interesting aspect of ADSL. By using MPEG-coded video it is possible to deliver video-quality movies over existing copper-loops to customers. A video-quality can be achieved by only 1.5 Mbps data rate. Together with pure VoD-services there might exist combined movie/information/advertizer-services in which commercial and non-commercial information providers and advertizers can deliver their information.