INTRODUCTION
Phone wiring isn't just for phones anymore. Ordinary
telephone wiring can't handle today's rapidly expanding communications
needs.
Today's homeowners expect their new homes to
accommodate:
- Multiple phone lines
- Internet service
- Video distribution, and other entertainment
services
- Data and security services
- Fax machines
- And the list goes on.
Faster and more reliable than ordinary phone wiring,
low-cost, high-tech copper wiring (Category 5 or better) should be installed
to every room in the modern home. It's what is needed to carry voice,
data and other services from where they enter the house to every room,
and from any one room to any other.
This guide gives the basics on wiring your homes for
the rapidly evolving information age—and today's homeowners demand it.
WHY NOW?
Unshielded twisted pair (UTP) copper information
wiring. often called structured wiring—is used today for offices, schools
and factories to provide local area networks (LANs), which allow computers
to talk to one another and to receive and send Internet and high-speed
computer data outside the facility. Category 5 ("Cat 5") is the current
standard, but will soon be supplanted by even higher-speed versions, known
as Category 5E (E for enhanced) and Category 6. (Category 6 has at least
twice the bandwidth, or information-carrying capacity, of Cat 5 at a small
cost premium.) 1
Right now, the typical home doesn't require the
capacity to move computer signals around as fast as the typical office.
However, offices get extensively remodeled—and rewired—every few years.
Homes do not. The wiring you install in your remodel must be ready to
serve indefinitely.
The phone wiring of the past, often referred to as
"quad" wiring because it has four copper wires, is now obsolete. Cat 5 or
higher speed wiring has four twisted wire pairs, or eight wires. All
are needed to provide the multiple services discussed here.
In fact, an FCC ruling, effective in July 2000, now
requires that homes, as well as businesses, be wired for the information
age. You should have no less.
COPPER UTP WIRING
What is it?
Copper UTP wiring contains eight color-coded conductors
(four twisted pairs of copper wires). It offers greatly increased bandwidth
compared with old-fashioned quad wiring.
The cable is small (roughly 3/16 inch in diameter),
inexpensive and easy to pull, although it must be handled with care.
Advantages.
Modern copper UTP wiring offers the following advantages:
Diversity
The Internet and computer communications, as well as ordinary phone signals,
can be carried throughout the home on modern, inexpensive, high-speed, UTP
cables. (To service a large number of TV channels, it is recommended to also
run high-quality coaxial cable, such as quad-shielded RG-6.)
More phone numbers
Several phone numbers can be made available throughout the house. Actually,
voice service requires very little bandwidth, and the addition of separate
numbers is almost trivial.
Bandwidth
Cat 5 has an approved bandwidth of 100 MHz (megahertz), while Category 6,
when finally approved as a standard, will likely accommodate at least 200
MHz when tested under stringent conditions. Bandwidth correlates with speed,
and these bandwidths are many orders of magnitude greater than the
bandwidth required for a . modern. 56 kbps (kilobits per second) modem.
Category 6 wiring, with encoding, will be able to carry at least 1 gigabit
(billion bits) per second. If you're counting, that's about 50,000 pages
of text per second.
New Services
The Internet is now available at high speed to many homes, but homeowners
won't be able to take full advantage of it if their wiring is inadequate.
One high-capacity technology now being offered by local phone companies is
DSL (digital subscriber line). And cable modems are being offered by cable
TV companies that bring in the Internet on the same coaxial cable carrying
the TV signals. Will these signals reach a dead end in the homes you wire?
Will the information highway end in a cow path?
Reliability
Interference on telecommunications lines can result in scrambled faxes,
interrupted on-line sessions and distorted video and audio signals.
High-tech twisted-pair copper wiring is designed to resist interference from
sources in the home, such as microwave ovens, vacuum cleaners, fluorescent
lights, power tools, other appliances and external communications signals.
The tight, accurate twist of the wire pairs and their balanced mode of
transmission are the reasons.
Approved
Performance of these cables is verified by Underwriters Laboratories (UL),
the international product testing agency, and similar groups.
LET'S GET SPECIFIC
When installing telecommunications wiring in
residences, follow these four simple principles to provide homeowners with
the most modern, flexible voice and data services:
- Use Cat 5 (or Better) UTP Copper Wiring
- Wire Every Room
- Use a Star Wiring Pattern
- Use 8-Pin Modular Jacks
Here's why:
Use Cat 5 (or Better) UTP
Wiring.
Most of the reasons have been mentioned: ability to move
large quantities of data around the house; ability to move a limited number
of TV signals from the point of entrance to anywhere and everywhere else in
the house (using a readily available adapter); ability to move other
signal-level entertainment to as many locations as desired; and of course
phone, fax and computer/printer connections wherever desired.
Wire Every Room.
Since the remodeler doesn't necessarily know the future
uses of the various rooms of a house, it's best to provide outlets virtually
everywhere. For instance, the kitchen is often the business center of a
household and thus needs multiple jacks.
Use a Star Wiring Pattern.
With star wiring, each outlet (jack) has its own
individual 'home run' of cabling extending back to a central distribution
device. There are three major advantages to this:
- flexibility– all changes in distribution of
services can be quickly and easily made at the central distribution
device. Each outlet can be treated independently from all others. (In
loop, also known as 'daisy chain', wiring. that is, where a number of
outlets are tied together in series—outlets cannot be treated
independently.);
- isolation of problems– when an interruption
takes place (nail through a wall and into a cable, etc.) only one outlet
is affected; and
- quality of signal– each additional
connection point is a potential source of interference and other problems
which can cause a loss of signal quality.
Having an extra outlet or two in some rooms,
particularly home offices, is a wise marketing move, since you can. t
anticipate future room use or furniture arrangements. This should be
accomplished with home runs to the additional outlets.
Most seasoned professionals strongly recommend running
. extra wire. to any location where it might be needed later. For example,
two 4-pair cables might be run to each outlet, rather than one, to enable
expansion and flexibility.
To further future-proof your new homes for only a
small additional cost, consider running Category 5E or 6 all the way, but
particularly for an area that might be used as a home office.1
Figure 1 (below) is a simplified plan of a
small, two-bedroom, single-story house. Note that all the wiring radiates
from a single distribution device (the star pattern) and there are multiple
outlets in each major room, including the kitchen and the porch.
Figure 2 (below) is a larger, two-story house,
with a den that could well serve as a home office, again showing the star
wiring pattern.
Use 8-Pin Modular (RJ-45)
Jacks.
These devices provide connection points for all eight of
the wires contained in the four twisted pairs.
Figure 3 (below) shows a wall outlet with two
such jacks.
Figure 3
Proper Installation is
Crucial.
Use a contractor who knows communications wiring and how
to install it according to strict guidelines, such as the following:
- how much pull can be applied to a cable (usually 25
pounds);
- how much separation is needed between data and
power cables (6 inches at least, crossing, if necessary, at 90 degrees);
- what fixtures to avoid (florescent lights in
particular);
- how far back the cable sheathing can be stripped
(no further than necessary, typically 1-1/4 inches);
- how much untwisting of the pairs can be done when
making connections (1/2 inch is usually the maximum recommended, 3/8 inch
is better)
- how tight a bend radius can be tolerated (usually
about 1 inch, although some designs are less sensitive than others); and
- how long a cable run can be (about 300 feet).
Important:
All connecting devices. central distribution device,
plugs on the ends of cables, outlets, etc.—should be rated for the
cable used. For instance, if Cat 5 cable is used, all devices must be at
least Cat 5 rated. If Category 5E or 6 cable is used, all devices should be
similarly rated.
Finally, the finished installation should be
thoroughly tested.
Video Cables.
In addition to UTP, it's prudent to also include
conventional coaxial cable for video distribution, particularly cable TV.
This is because it is difficult to predict whether many channels. well over
100, for example—may become a reality in the near future, some channels of
which will be the more bandwidth-consuming high-definition television
(HDTV).
If coax is installed, quad-shielded RG-6 coax, with an
all-copper center conductor, should be used for superior performance.
(Copper-plated steel center conductors are also available, providing
additional stiffness, but are unable to handle low-frequency currents used
to power some devices.) A lesser grade, RG-59, should not be used.
IN CONCLUSION
Now is the time to start wiring for the
Information Age. High-level UTP wiring to every room is a clear advantage at
minimum cost.
Note:
1 In the telecommunications and electronics
industries standards are important. However, because of the fast moving
nature of these industries the marketplace usually runs well ahead of the
standards-setting process.
Cables meeting the expected performance standards of both Category 5E and 6
are commercially available from multiple vendors. The standard for Cat 5E is
now official, but for Cat 6 it is still pending. Use the best cable
available.
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