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Residential Broadband Evolution
Many services envisioned for the NII will demand significant
amounts of communications bandwidth. To extend these services to
the general public, broadband access networks to private residences
and apartments will play a critical role in the NII. Residential
broadband (RBB) networks are already widely deployed for
entertainment video distribution services. Future residential
broadband networks will provide increased bandwidth and two-way
interactive capabilities supporting a wide variety of
applications.
To characterize today's RBB networks and to understand how they
are evolving to provide the capabilities needed in the future NII,
the XIWT invited industry experts representing CATV companies,
local exchange carriers, RBB equipment manufacturers, and satellite
communications service providers to discuss current and future RBB
networks.
The following is a summary of the views of these industry
experts. It does not necessarily represent the views or positions
of the XIWT or its member companies.
Residential Broadband Today
Access Architecture
Today's residential broadband (RBB) is composed of over-the-air
broadcast networks, CATV networks, microwave access networks, and
direct reception from home satellite antennas. With the exception
of emerging satellite-based delivery systems, today's RBB access
networks are based on 6-Mhz analog channels. In a recent study of
CATV networks conducted by CableLabs, typical downstream capacities
were as follows:
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22 percent have less than 30 channels;
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64 percent have 30 to 53 channels; and
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14 percent have 54 channels.
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Although the amplifier housings employed in current CATV
networks are designed to accommodate a return path amplifier (i.e.,
they are two-way ready), most of today's CATV systems have
unactivated return channels. Roughly 20 percent of today's CATV
systems use some fiber-optic links to bypass long amplifier chains
in the trunk portion of the network. Currently a mix of 300-, 400-,
450-, and 550-MHz amplifiers is used. Service is typically provided
to residences and apartments, with relatively few business
locations connected to CATV networks. There is usually only a
single CATV operator in a given service area, with nascent
competition from microwave and direct broadcast satellite service
providers. TVRO (television receive only) background antennas that
are 1 to 2 meters in diameter are used by a small fraction of
residential customers.
Services available over today's RBB networks typically consist
of the following core set:
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Basic video;
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Subscription pay;
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Pay-per-view;
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Special events; and
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Shopping channels.
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In addition, the following emerging services have been deployed
on a limited basis:
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Near video on demand;
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Electronic video guides;
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Low-speed and high-speed data access;
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Digital video services via high-power satellites;
and
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High-speed, downlink-only data via high-power
satellites.
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