dsl+ 1100 LAN.book - the world of dLAN® ... devolo AG

6
Introduction |
1 Introduction
1.1 What is ADSL?
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The sheer speed of development of computer technology over the last few years
has resulted in a huge increase in the volume of electronic data traffic. More
users want to send and receive a constantly increasing volume of data. A
demand which offers fertile grounds for the development of broadband technology.
ADSL (Asymmetric Digital Subscriber Line) and the advanced ADSL2+ is a transmission
technology which offers genuine broadband communication to the user.
The “last mile” connects the customer to the network via copper telephone lines.
Because telephone lines are used to transmit data, the spread of this access
technology has been relatively fast.
Together with the ADSL technology on the copper twin wire of the telephone
lines, three differently large frequency ranges are used: Two for data communications
and one for telephony. The term 'Asymmetric' indicates that the transmitting
and receiving channels can carry different quantities of data:
� When the user surfs the Internet, the data sent to the Internet service provider
(ISP) tends to carry less information (e. g. addresses of web sites or emails).
The transmission rate of up to 1 Mbps is generally sufficient for this
purpose.
� To load multimedia content (video sequences, animations, images etc.) onto
the computer from the Internet at acceptable quality and speed, a transmission
rate of up to 24 Mbps brings significant savings in terms of cost and
time.