How does Structured Wiring work?
As a starting point, it is useful to think of a structured wiring system in terms of your house's electrical system.
Electricity flows into your house through a main power cable. This cable connects to a circuit breaker box, where
it is separated and sent down smaller electric lines. These lines wind their way through your walls, ultimately
ending at power outlets placed throughout your home. You then plug devices into the outlets and use them.
A structured wiring system functions similar to this. All external data lines (such as cable television,
telephone, or internet) come into the house and are connected directly to a central control box. This box
is usually the size of a large electric circuit breaker panel, and is placed in a similar location, such
as in the basement or a utility closet. Within the control box, each incoming signal is split and sent
down wires to multiple rooms in the house. In a good quality central control box, the splitter will also
contain a signal amplifier. This device makes sure each outgoing signal is as strong as the single incoming signal.
Without an amplifier, the power of the incoming signal gets split among each outgoing wire, often resulting in
significant performance loss. In layman's terms, this means a snowy TV or phone line with static.
From this box, bundles of wires run through the walls of the house to different rooms. With a good structured
wiring package, these wires will be installed in a "home run" or "star topology" configuration. This means that
each set of wires runs to only one outlet. This is in contrast to "daisy chaining", which means one line goes
first to your kitchen, then to your living room, then to your bedroom. Although daisy chaining is less expensive,
it introduces problems as the signal quality in your bedroom (the last stop) is much poorer than that in your
kitchen (the first stop).
The wires included in the bundle vary by manufacturer, but you should look for at least two coaxial
cables of RG-6 quality and two twisted pair cables of CAT-5 quality. Coaxial cable is just a fancy
name for the typical black cable you use for purposes such as connecting your VCR to your television—the
type with the copper wire sticking out the end and the annoying screw attachment. RG-6 is a rating of quality;
some manufacturers use RG-59 or lower grades, but you should avoid these as your picture quality will not be as good.
Twisted pair is another fancy name, and refers to the telephone cable that runs to the phone jack on your wall.
It is called twisted pair as it consists of two wires that are twisted around each other. (As strange as it may seem,
the twisting actually improves the quality of the signal!) CAT-5 is a an abbreviation for Category Five, another
indicator of quality. Generally higher numbers indicate better quality, although you should note that CAT-5e (our standard cable) is
one step better than CAT-5.
These cables are often bundled together and covered with a plastic coating. This is advantageous as a
bundle is easier to install, and the stronger wires (RG-6) help to protect the weaker wires (CAT-5)
during the installation process. (With good quality wires, there will be no loss of performance or
interference from bundling.) This bundle is run through the walls of your house, and terminated at a wall plate.
These plates are about the same size as a normal wall face plate. Depending on the wires included in the bundle,
it will have from two to eight different outlets. For example, with the four-wire bundle described above,
the wall plate would have two cable jacks and two phone jacks.
Why so many wires?
So far, the structured wiring system described does not offer much beyond a house's standard wiring.
This is where the second cable and phone lines become important. The first cable line carries a signal
from the control box to the wall plate—for example, a satellite TV signal. The second cable line can
then be used to carry a signal back to the control box—for example, the output from your DVD player.
With the appropriate module inserted in the control box, this DVD signal could then be amplified and
sent back over all outgoing cable lines on an unused channel number.
You could then watch the DVD on any
TV in your house simply by tuning to the previously unused channel.
Where this technology really shines is when setting up a home computer network. For example,
you can use a single CAT-5e twisted pair line to both send and receive computer data. An advanced
control box will be able to decipher the data, and send it to the correct location. Thus, data
coming in over an ISP connection will be sent to the correct computer, allowing for multiple users
to share a single broadband ISP connection with no interference. Similarly, data can be sent from
one computer and correctly routed by the control box, whether it is an e-mail message to be sent
to a friend overseas, a file to be printed on your color printer in the upstairs office, or simply
an instant message to your spouse working downstairs.
|
