Today’s home wiring includes more than the standard suite of electrical connections. Dedicated wiring for data, telephone, audio, and video are fast becoming standard options.

What is structured wiring?

Structured wiring is a generic term used to describe many different types of residential wiring products currently on the market. These products all have the same basic purpose-to efficiently distribute a variety of data signals throughout your home. Signal types supported range from those you are probably familiar with, such as cable television and telephone, to those you may not be so familiar with, such as Ethernet computer networks. To give some more practical (and exciting!) examples, a structured wiring system is the backbone which will allow you to:

• Play a DVD in one room, and watch it on any other tv in your house
• Listen to your stereo in any room of your house
• Place video cameras at your front door, in the back yard, and in the baby’s room and watch the pictures on any TV
• Hook multiple computers up to one internet connection
• Send files between all computers in the house
• Share devices such as computer printers and fax machines
• Have over a dozen different phone lines
• Easily make adjustments to all of these options as your family’s needs change

How does it 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 staticy phone line.

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 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.

Structured Wiring is very different than the older way of doing things.

On the left is the older ‘Daisy Chained’ method of wiring, if you can go as far as calling it a method. Cables would be run from one outlet or jack to the next and then on to the next and so forth. Splices were often used in the telephone wiring. CATV splitters would be stuck away deep inside walls or in attics somewhere. Little attention was paid to good wiring techniques – as long as the wires were touching every thing would be ok. The signal quality and strength at the end of the chain would be seriously degraded and inconsistent. If one of the connections were to fail all of the devices connected further on down the chain would fail as well. With this method the phone lines follow different paths through the home as the video which are different again from the network. And each of the wiring types usually has it’s own separate outlet plate. The wiring paths and the location of splices and splitters was rarely documented. Adding to or troubleshooting or documenting this mess was nearly impossible.

On the right is the Structured method. One of the main features of this is having a central location and how all of the cables from the outlets go back to the central location. This is commonly called a Home Run configuration. Typically one outlet plate is used for all of the wiring types – phone, video, network or whatever. And the wires are typically run in bundles containing ALL the types of wiring. No splices are used.

Benefits

A structured wiring package means that multiple data distribution options are readily available in the home. This is where the second cable (RG-6) and data (CAT-5) lines become important. The first cable line carries a signal from a 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, this might be the output from a DVD player. With the appropriate hardware, this DVD signal could then be amplified and sent back over all outgoing cable lines on an unused channel number on every television. The DVD could then be watched on any TV in the house simply by tuning to the previously unused channel.

Where this technology really shines is when setting up a home computer network. A single CAT-5 twisted pair line can be used to both send and receive computer data. An advanced control box, commonly known as a router, will be able to decipher the data, and send it to the correct location. Thus, data coming in over a high-speed Internet connection will be sent to the correct computer, allowing for multiple users to share a single Internet 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 a color printer in the upstairs office, or simply an instant message to your spouse working downstairs.

The advantages of structured wiring are

• Configurability - With all of the cables running back to the Central Wiring Panel you can easily change how and what these individual cables are connected to and what they are used for.
• Troubleshooting - Each of the cables can be individually isolated from the rest of them and tested for shorts and opens if need be.
• No splices - Splices are taboo here because they are prone to failure and can pickup noise and interference and, quite simply, aren’t needed here.
• More consistent signal quality - with all cables running back to the Central Wiring Panel they can all be connecter to the same source and get the same signal level. You can easily avoid having some outlet passing through more splices or splitters than others.
• Choice of wiring types - The use of high quality cabling is stressed here. For video this means a high quality RG6/U Quad Shielded cable is typically used instead of the older RG59. The RG6 Quad Shield has less signal loss especially at the higher frequencies used for DSS (satellite) and is less susceptible to interference. For the data network this means a high quality CAT5 , CAT5e, CAT6 or even fiber optics. For the phone this means the same CATx cable used for data instead of the older 4 conductor phone cable resulting in less noise and interference pickup and the capacity for 4 phone lines instead of 2 . The idea here is use the most advanced cabling you can afford. You may not need all the capabilities these advanced cables provide today but with home networking and entertainment evolving so quickly you may find them quite useful sooner than you think.
  

How much will it cost?

Ah, yes – the important question. a basic structured wiring system can be purchased and installed in a new home construction for approximately $1 per square foot of living space. This system would consist of a control box capable of simple video and telephone distribution and CAT 5E wire bundles running to wall plates in each bedroom, the living room, the garage and kitchen. The total cost to purchase and install the same system in an existing home can cost up to twice as much, or $2 per square foot of living space. Of course, as these are rough estimates only, actual prices may vary dramatically due to custom installations above and beyond what is mentioned above.