By Steven Totolo, President, Total Voice Control

With the proliferation of new technologies available to homeowners, residential cabling will have to be upgraded to match these advances. Consumer products such as WebTV, Internet Phone and games over the Internet will require wiring to handle the amount of information travelling through them. The standard home today is using wiring designed 50 years ago for applications that were never conceived at that time. Homes must be wired for the requirements of today’s homeowners as well as for future products not yet designed.

Traditional household cabling

Half a century ago, there were no standards followed by North American homebuilders when installing cable. In other words, cabling was simply done in an ad-hoc fashion. The first trades on the building site would drill holes to run their services. Subsequent tradesman would later arrive and proceed to install their wiring via the existing wire paths created beforehand. This resulted in electrical, phone and television cables strung through the same paths and holes throughout the home, which caused cable usefulness to degrade. Even with today’s technology, such as 56k modems, household cabling potentially restricts the modem data speed to half because of the phone wire installation. Consumers are generally unaware of this restriction and will falsely blame hardware for the slower performance.

Overall, there are several methods of interconnecting wiring used in traditional homes: daisy chain, bridge-tap, and star. Telephone lines are often daisy-chained from one room to the next. Should a break occur in the wire, several rooms could be affected, as illustrated in Figure 1. This arrangement is problematic because finding the location of the broken wire requires tracing the wire from tap 1 through to tap 5. To repair the break, an installer would need to connect a new cable between taps 2 and 3,yet leave the remaining original wire intact. Equally problematic, taps 3 to 5 would be kept out of service during repair, interrupting regular phone use.

Another method of connection is a bridge-tap or splice, which also weakens phone line signals because noise can be induced at this point. A similar problem affects television cable. This is so because splitters placed along the line weaken the signal every time they are used. When additional connections are left unterminated or unconnected to a device, reflections and interference can affect the whole video distribution.

Another problem with existing cabling is the installation process. Wires that run along joists and studs are usually held in place with staples. The standard staple gun fires the staples hard into the cable, deforming and changing its characteristics and performance. There are times when cables are placed into awkward locations or run through tight turns, pinching the cable.

Moreover as homeowners’ needs changed, additional cabling might have also been installed, yet not match the type and quality of the original wiring. Additionally, most homes were only wired for one cable television connection and one or two phone connections. Unfortunately, this approach did not accommodate future lifestyle changes.

The star formation (Figure 2) is considered by industry to be the proper installation of new wiring. In this formation, all cables start at one location, usually at the entrance of the telephone and cable television wiring site to the home, and travel directly to their intended destination. This scheme provides maximum flexibility for testing, and installing home LANs or intercoms, and improves signal quality and installation of new services.

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Part 2 - Properties of new wires
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Steven Totolo is president of tvcAutomation, a home automation specialist and a member of the CABA Standards Committee. He can be reached at (613) 795-7117; fax (613) 737-5323; email: sales@tvcAutomation.com