Page 24 - Broadband Internet The Basics for Next Generation Networks (NGN) in Telecommunication.

Cable Access

Networks

Cable

Cable Access Network

On the other side, cable networks were •In such case there is no need for
initially designed to carry the TV in additional investments in the cable
downstream direction, which can cause network, but there is a need for
problem for two-way communications alternative connection for the upstream.
(downstream and upstream) as used for all
Internet services. Additionally, another drawback of this
There are different models of network approach is that the data is received by
access to the Internet through cable all users on the same cable in the
networks. downstream direction.
One approach is a hybrid network, where •Approach which is most used nowadays
data in the downstream direction (i.e., for Internet services over cable access
toward the end user) is sent via cable TV network is two-way data transmission
network, and for the upstream direction is
used another network such as dial-up over the cable network, based on
access via a telephone line. DOCSIS (Data-Over-Cable Service
•In this approach the bit rate in the Interface Specifications)
downstream can be several tens of
megabits per second and cable network
continues to operate with unidirectional
amplifiers that normally exist in the cable
networks to enhance the TV signals.

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