A sure trend in CCTV is migrating these systems from analog to digital Internet protocol (IP). This means that instead of stand-alone systems with separate cabling for both the analog and the digital, IP-based systems will converge onto a single network. When translated into the physical realm, this means that unshielded twisted pair (UTP) cable will replace time-honored coax cable wired to cameras.

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Installing a UTP-based system today will mean that your transmission media will support legacy analog surveillance systems as well as newer IP-based technology without having to replace the cable. Operating security cameras on UTP will improve the signal and picture quality (for both analog and digital video signals). There are other advantages of utilizing UTP, including:

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• UTP utilizes balanced transmission with natural noise immunity;
• UTP offers high bandwidth capabilities;
• UTP does not have ground loop problems;
• one UTP cable can be used for powering the device (poE or analog power injection), capturing the video and PTZ control; and
• substantial space savings in the pathways from reduced cable diameter.

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The path to IP does not necessarily mean a complete conversion to IP cameras. Analog cameras can operate over a network using UTP cabling by placing transceivers between the existing analog camera and the network cabling to convert the signal from an unbalanced coaxial signal to a balanced twisted pair signal.

As a security installer, you will need to learn additional installation techniques to terminate the cable to an RJ-45 connector assembly. Although all transmission parameters are sensitive to discontinuities caused by connector termination, near-end crosstalk (or NEXT) of twisted-pair systems is particularly sensitive to conductor untwisting and other installation practices that disturb pair balance and cause impedance variations.

To prevent any signal degradation, remember these important guidelines when terminating into an RJ-45:

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• Remove only as much cable jacket as is required for termination.
• Follow the manufacturer’s instructions for mounting, termination and cable management.
• Minimize the amount of cable pair untwisting during termination to connecting hardware. For UTP cabling, the amount of untwisting must not exceed:
    
• 24mm (1 inch) for Category 3 cables;
• 13mm (half-inch) for Category 5e and 6 cables.
• Each 4-pair 100-ohm UTP cable must be terminated in an eight-position modular jack at the work area. Two formats, known as T568A and T568B, have pairs 2 and 3 in different locations, so be familiar with each layout. The tools that you will need include a jacket stripper, wire cutter and a punchdown tool.

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The simple steps for terminating a Category 5e cable, demonstrated here with Berk-Tek’s LANmark350, include these procedures:

1. Strip back the cable.
2. Cut back the ripcord.
3. Position the pairs left to right: blue, orange, green and brown, matching the colors to the sequence on the jack.
4. Untwist to allow a half-inch of exposed wire from the punchdown to the first twist out of the jacket.
5. Using the punchdown tool, punch down the pairs all the way into the color-coded grooved slots. The punchdown tool will automatically trim the excess wire.
6. Attach the protective stuffer cap, which protects the punchdown and adds stability to the cable.

Contributed by Carol Everett Oliver, a registered communications distribution designer (RCDD) and marketing analyst for Berk-Tek, a Nexans Co., Holland, Pa., a manufacturer of fiber and copper cable products (www.berktek.com).