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Complete refresh 12/13/02
Structured Cabling for Home Broadband Distribution
This page summarizes our view of the "whys and hows" of home networking based on structured cabling.
Structured cabling is used for many different applications. Spend some time figuring out what you'll need now and in the future. Here's a list of applications and our current view of "recommended practices".
Many homes with broadband service (cable or DSL) have more than one PC; users would like to share the broadband connection with PCs in different rooms, using a single broadband modem. Many would also like to share printers, files and a central back-up system. For this, they need a local area network (LAN).
While new "no new wires" LAN technologies are coming to the market, we believe the best practice is still running wires through the walls - certainly for new construction and for rebuilding. Building a network with "structured cabling" and 10/100 Ethernet provides the most flexibility, "future proofing" and the highest reliability and performance. While pulling wires is expensive, the capital cost for the Ethernet components is low; many vendors are competing to provide the pieces: network interface cards (NICs), hubs and routers. Virtually all new PCs now have built-in Ethernet connections and most cable and DSL have Ethernet, so it is also the simplest solution once the wiring is in place.
Originally designed for office wiring, structured cabling based on the "Category 5E" standards for cable and components is the approach we recommend for home networks. Plan to pull one CAT5E cable from a central point ("the wire center") to each room; this is sometimes called "home run" cabling.
In the wire center, a "structured cabling enclosure" organizes the cabling and connections. The picture shows a Greyfox enclosure with telephone, video and data modules -- data cables are blue, video orange.
In each room, the CAT5E cable is terminated with a CAT5 RJ-45 jack (which looks like an oversize telephone jack) near where you'd plan to plug in a PC (or some future appliance that will operate over the same network).
Many homes have two or more phone lines, supporting fax machines and modems (to say nothing of teenagers!). Broadband will reduce or eliminate the need for dedicated modem lines, and will probably eliminate analog lines completely some day. Since this may be some time coming, we'd recommend providing for four phone lines (standard CAT5E cable provides four pairs for this).
The best practice today is to run a Category 5E cable from the wire center to each room. "Home run" wiring is far preferable to the old telephone wiring approach where all the phone jacks were connected together with a cable running from jack to jack.
In each room, the CAT5E cable is terminated on an RJ-45 jack; an adapter cable is used to break out standard RJ-11 modular jacks for standard telephones. (In our house, we used two RJ-11 modular jacks, with lines 1-3 on one jack and lines 3 and 4 on the second. This approach accomodates three-line phones [which are often designed for a 3-line jack] and four-line phones [often designed for two two-line jacks]. But the recommended practice today is to use an RJ-45 jack and an adapter cable.)
In the wire center, the CAT5 cables are terminated with telephone modules. (We used old-style "66 blocks" in our house but plan to replace them soon.)
At about 10 cents a foot, CAT5E cable is inexpensive compared to the cost of pulling the cables. It costs little or no more to pull three CAT5Es than two.
We'd therefore recommend pulling a third CAT5E to each room. It can be left as a spare or wired to a third RJ-45 and used as a second phone cable for fax machines, analog modems, and TV set-top boxes (most of which still use telephone lines).
People want to provide cable connections in many rooms to connect TV sets or cable modems. They may want to distribute the output of a cable set-top box or a satellite receiver to many rooms. They might want to make the "monitor" output of an A/V receiver available throughout the house, permitting any TV to show a VCR, DVD, or premium cable program.
While video distribution may one day be feasible with CAT5E cabling or wireless, the standard practice today is to use RG-6 coaxial cable with "home run" wiring from the wiring center. We'd suggest running two RG-6 cables to each room, using one for video to the room and the other as a return for a camera or other video source.
You may want to have loudspeakers in many roons to listen to the radio or CDs from a central sound system. While we believe that this will be carried over CAT5E, power-line or wireless in the future, today you'll need loudspeaker wiring for sound.
We recommend running low-loss "Monster"-type loudspeaker cable on a "home run" from the wire center (two cables are of course required for stereo). This approach avoids the need for a stereo amplifier in each room.
If you're willing to put an amplifer in each room (or if your TV has stereo audio input and you're satisfied with the built-in speakers), an alternative would be to run two additional RG-6 cables for "line audio".
Here's a concrete example of how to do structured wiring in a house, based on what we did in our own home in late 1996. With revisions, it's what we've recommended to friends as the basis for contractor quotes. Structured cabling enclosures of the type shown in the picture above were not yet available for residential use, so we used a plywood panel; we hope to replace it with a modern enclosure to reduce the space and better organize the cabling.
Planning the Cable Runs
Pick a place in the house as the wiring center, preferably close to where the telephone and video cables enter the house. The garage, basement, furnace room or utility room would be a good choice.
Work out a plan to run cables on a "home run" from the wiring center to each room. In an existing home, it may be easier to have additional "sub-centers" (we have one in our attic). If so, plan to run "vertical cabling" from the wire center to each sub-center, and "horizontal cabling" from the subcenter to each room it serves.
Running the Cables
Mount the structured cabling enclosure in the wiring center. (Since we didn't have an enclosure, we used a plywood sheet for mounting terminating equipment.)
Run a group of structured cables from the wire room to each room of the house.
Leave sufficient slack in each cable for termination. Label all cables at each end and create a cable index showing all cables and locations.
Wire Center to Rooms
Provide the following cables to each room:
Wire Center to Utility Entry
Run structured cabling from the wire room to the utility entry point:
Terminate the first category 5E cable from each group (the "LAN" cable) on a Category 5E patch panel in accordance with EIA/TIA 568A or 568B (you can use either one, but you must be consistant throughout the house). This will be a module in the structured wiring enclosure. (We used a 12-port Cat 5 patch panel in our house.)
Terminate the second category 5E cable from each group (the "phone" cable) on a telephone module in the structured wiring enclosure. (In our house, we connected the house cables to the right hand side of a "66-type" 25-pair telephone punch-down block, with six cables to each 66 block, following the standard code pair sequence for telephone wiring. We used the type of 66-block which is split evenly with two pins on the left and two on the right for each wire.)
Decide whether to terminate the third cable from each group in the same way as the phone cable, or whether to leave it unterminated.
Terminate one Category 5E cable from the utility entry point (the "telephone entry" cable) to the "input" side of the telephone modules. (We connected the "entry" cables in common to the left side of each 66 block, using patch clips to connect the two sides of the block.)
Terminate the coaxial cables with "F-type" screw-on connectors to a video distribution module. (We used a splitter but will replace it with an amplifier.)
Select an appropriate wall outlet system providing CAT5 RJ-45 jacks, F-connector feed-throughs (for video) and banana jacks (for loudspeakers). Provide a triple receptacle box in each room (one for Category 5 wiring, one for speaker wires, and one for video F connectors). Or use single or double boxes if the LAN, video and speaker cables are going to different parts of the room.
Test all CAT5E cables and jacks using appropriate test equipment and adapter cables to demonstrate that all wiring is terminated correctly and that LAN wiring conforms to EIA/TIA specifications.
Test speaker wiring for proper operation.
Test video wiring for proper operation.
System Dynamics Inc. is not an expert in home wiring. The information above is based on our own experience and is provided solely as a service for our readers. We recommend engaging a professional electrician and/or cabling installer to assist in undertaking a home wiring project.