With Broadband Fast Becoming the Internet Access Means of Choice, a Review in Network Wiring Basics Is in Order.
According to a recent report from comScore Networks, broadband usage is rapidly catching up with narrowband. In San Diego, the most broadband-centric area in the nation, more than 50 percent of Internet subscribers use broadband. Nationally, of the 150 million estimated online users, more than one-third are connected via broadband.
These statistics send a very clear message to homebuilders: Internet access is truly becoming commonplace in American homes, with ever-increasing demands for speed. Fortunately, homebuilders are taking note. In 1998, no more than 8 percent of new housing starts included the structured wiring necessary to support home networking. That figure has risen by 500 percent, to the point where 40 percent of new houses now have broadband access.
With that growth, homebuilders not familiar with broadband demands and wiring needs should be.
Wiring for Home Networks
The basic wiring needed for home networking—structured wiring—is required by the Federal Communications Commission (FCC). (See sidebar.) Since the telephone wiring specified in the FCC ruling must now be installed in exactly the same configuration (star distribution) as is needed for home networking, home builders should consider completing the job at minimal cost and add data wiring as well.
Typically, two twisted four-pair cables (Category 5e is most common) are run to each location from a communications hub, one for phone and one for data. Where TV signals are needed, one or two RG-6 coaxial cables are run (one to carry the signals downstream, one upstream for such devices as cameras, if needed). When cables are being run it is always a good idea to run extra cables for future expansion since wire is inexpensive. Your homebuyers will thank you later.
Standards are extremely important because they lead to uniform design and installation practices. The TIA/EIA-570 residential standard goes well beyond the FCC ruling. It is not a law or building code. Nonetheless, it provides a uniform platform for manufacturers to design structured wiring, communications devices and electronics. The TIA/EIA-570 standard allows products from multiple vendors to be mixed and matched without degrading system performance, and it allows installation and support personnel to know where to look for things and how to troubleshoot problems.
Following the recommended solution of two Category 5e cables and two RG-6 quad-shield cables to every major living area of the home provides your customers with the foundation and flexibility to accommodate most of their communications needs. Structured wiring differs from traditional telephone or cable TV wiring in at least two important ways: first, it uses higher-capacity cables, and, second, it uses what is known as a star-wiring configuration.
Communications applications such as networks, high-speed Internet access and video distribution rely on dedicated circuits. All bridging and connecting should be performed at a central location.
In modern homes, each cable runs directly from an outlet to a central distribution device where all of the outlet cables are then connected to the proper services.
Central Distribution Devices
The CDD should be matched to future needs of the structured wiring system. Planning considerations include deciding upon a location for the CDD. Ideally, it should be located as close to the middle of the house as possible, protected from weather and burglary and not placed on a firewall. Choosing a central location reduces cabling costs and the length of the cable runs. Typical locations include under stairs, in closets, basements, garages or in utility closets.
How much space does it need? Most manufacturers have designed their wiring boxes to recess-mount between studs spaced 16 inches apart (measured from center-to-center), or to surface-mount. The boxes are typically 14–14 1/2 inches wide, with lengths varying from approximately 20–60 inches, depending upon the size of the house and the amount of electronics to be housed. In some large homes, two boxes may be needed which can be mounted side-by-side in adjoining stud cavities.
The CDD must accommodate all of the cable runs, service runs and connection points. A well-designed box will allow the cables to be routed and stored neatly. Second, the box must accommodate modules such as video amplifiers, network hubs, video modulators, security/home control panels and their associated power needs. A non-switchable 15-amp duplex outlet should always be available within 5 feet of the box. Whole-House Home Networking
Some builders question if home networking is really needed in every room of a home. The question to really ask is: In what rooms of the house will the homeowner never want a phone, Internet access or cable television?
The easy and affordable answer is to properly wire all major living areas of a home, such as bedrooms, living rooms, family rooms, kitchens, dens and even basements, patios or decks. A key component of a properly wired home is its central distribution device.
Whole-house wiring offered as a standard product in your homes also sets the stage for the sale of profitable options. By properly wiring, builders provide maximum flexibility at a nominal cost. Clearly, the demand for home networking is rapidly growing.
William Black is vice president at the Wire & Cable, Copper Development Association Inc. He can be reached at wblack@cda.copper.org.