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Seventy-five years ago, wires for electrical service were run on the outside of the walls — home builders didn’t think people wanted electricity in their new homes. As recently as ten years ago, cable television companies were still installing the coaxial cable for their new customers. Again, only those with money to burn could afford to pre-wire a house for the new technology.
Today, homes are routinely wired for cable television and telephone service. In most homes, however, the wiring is obsolete before the new owner even moves in. Advances in technology bring increased demand for higher quality cable in homes, and today’s technology requires improvements in the way those wires are installed.
Home Wiring Comes of Age
Most builders still use what’s known as "bell wire" for telephone service. In the days when a second telephone line was a luxury and voice calls were the only traffic, this cabling was sufficient. Inexpensive to make and easy to install, bell wire has been installed in millions of homes. Unfortunately, data transfer on bell wire is very slow — slow enough to prevent the use of ISDN and xDSL.
Some homes are now pre-wired with coaxial cable for television.
The most common cable used is RG-59 — a single solid conductor in the center of an
insulator, wrapped with a braided wire shield and housed in plastic wrap. It too, has been
installed in millions of homes, as the cable television industry has brought hundreds of
TV channels into American homes.
Both of these cable types face serious limitations, however. Bell wire can handle only two telephone lines, and its construction leaves it susceptible to electromagnetic interference. Digital television and cable modems require more bandwidth than RG-59 can provide, and like bell wire, RG-59 is prone to interference from outside signals.
Poor installation practices compound the limitations inherent in the wires. Telephone and television cables must be run as far from electrical power lines as possible. Even at household voltages and current levels, power lines generate electromagnetic fields which can interfere with the signals traveling through coax or bell wire. In addition, many builders save money by "daisy-chaining" telephone outlets. With this method, outlets are connected in series. This method saves time and cable costs during the installation, but the failure of a single outlet can cause the whole system to go down.
The Way of the Future
Using higher grades of cable in a system offers a better solution. Some builders and electricians are beginning to use the same telephone cables for homes that has been used in businesses for years. Known as Category 5 (CAT 5) telephone and data cable, this types uses eight wires, divided into four pairs. Each pair is twisted together, and the four sets are then contained in a single jacket. This method allows each pair to have a distinct electrical "signature," which minimizes the electromagnetic interference (EMI) within the wire.
Compared to bell wire, CAT 5 cable has less static and greater bandwidth — up to 100 million bits per second. CAT 5 also provides up to four telephone lines from a single cable, and can be used to link computers together on a network.
Just as bell wire can limit the use of telephone circuits, RG-59 can cripple the best television system. As cable TV companies add new channels and begin to introduce two-way communication, the bandwidth limitations of RG-59 doom it to obsolescence. RG-6, on the other hand, is rated at up to 1.5 gigahertz (Ghz) — about double the rating for RG-59. The superior protection provided by four separate electronic shields within the cable also ensures that signals traveling through RG-6 remain intact.
CAT 5 cable is also able to carry more data. Compared to bell wire, CAT 5 cables has less static and greater bandwidth — up to 100 million bits per second. CAT 5 also provides up to four telephone lines from a single cable, and can be used to link computers together on a network.
Once the home is fully wired with CAT 5 cabling, each room has far more potential than for just telephone and television. Now you can plug a computer into a wall jack and access a home local-area computer network. Or route the movie from your VCR to any TV in the house. Or even see who’s at the front door on your TV by switching to the security camera. The possibilities are virtually limitless — as long as the home is wired for living.
What’s Next?
Created specifically for residential applications, structured wiring systems offer an organized approach to home wiring. This article specifically references the OnQ™ Home Wiring System by AMP Building Systems. The OnQ structure system consists of an enclosure, a set of modules that are installed in the enclosure, outlets for the various types of services, and cables that connect the outlets to the enclosure modules. Additional cables connect signal sources to the enclosure. The enclosure is a box that can accommodate modules in nearly any combination.
With the OnQ system from AMP Incorporated, the telephone and television cabling in your home can support all of the advanced communication technology available today. And it allows you to add more options as your needs expand — even capabilities that haven’t been developed yet.
The "heart" of the OnQ system is the service center. Serving as the "home" for the many wires that result from a home run system, the enclosures come in three sizes. The basic cabinet holds modules to support a basic telephone/TV/data network, while the largest enclosure is large enough to add security, home management, whole-house audio, and several other larger modules.
Within the enclosure, cables are routed to separate modules for each function. Discrete modules route the signals for analog telecommunications (voice and fax), digital telecomm (ISDN and xDSL for high-speed Internet access), video (cable television, satellite TV, and security cameras), audio (stereo music or intercoms), and in-home local-area networks.
If the home is really wired for living, the OnQ service center can hold the AMP Home Management System (HMS) controller. With the HMS, you can have a security system integrated with lighting control, programmable thermostats to cut heating and cooling costs, and control of other home systems such as lawn sprinklers when you’re home or away. An ordinary touch-tone telephone gives you access to all your home’s systems, whether you’re in the backyard at a barbecue or across the world at a business meeting. You’ll never need to come home to a cold, dark house again!
All of this technology is available today. And no one can predict what will be available for the home 15, or even five, years down the road. With proper pre-wiring, though, you're prepared, no matter what comes. With a house that's wired for living, you can add new modules to the service center, keeping current with any advances in electronic technology.
AMP is the world's leading supplier of connectors and interconnection systems, serving customers around the world in a wide range of markets from consumer goods to communications and computer systems. Employing more than 45,000 people in 50 countries, AMP (NYSE:AMP) achieved record sales in excess of $5.47 billion in 1996.
