14 Oct 2016

Cost considerations are an important reason to use existing installed cable as part of a new system infrastructure. Extenders in the form of media converters can help.

For almost three decades, video surveillance systems existed in the form of analogue systems. Video coaxial cable was the primary method of transmission with a limited distance of about 750 feet. Analogue systems required separate power supply located at each security camera site. Today, new technology often solves one problem and creates another. Internet Protocol/Power over Ethernet (IP/PoE) systems eliminate the need for local power supply, thus saving installation costs. The drawback is the restriction to only 328 feet and the required use of Cat 5e or above cable.

Extended transmission distance

So tens of thousands of video surveillance cameras are waiting to be converted to IP, and have been transmitting over coax at distances two-and-a-quarter-times greater than the Ethernet limit. The advent of extenders helps to solve this problem. In addition, the use of extenders for Cat cable and even single-pair alarm wire helps to add to the types of IP/PoE conversions while extending distance as far as three thousand feet.

Tens of thousands of cameras
are waiting to be converted to IP,
and have been transmitting over
coax at distances two-and-a-
quarter-times greater than the
Ethernet limit

Considerations while using extenders

Use of extenders requires taking several considerations into account. First and most important is a careful reading of specifications. A statement can be true while not applying to your applications.

Let’s take IP/PoE transmission over coax as an example. A manufacturer’s product can state it has this feature and will meet your transmission requirement of X number of thousand feet. However, a careful reading reveals that achieving this requires RG 6 cable while you have RG 59 installed. You need to maintain a 100Mbps bandwidth and provide your cable with 12.95 watts of power. But as both bandwidth and power decrease with distances obtainable from many types of extensions, you realise that both are much less at the extended distance you require. In short, just depending on a product to make a simple specification statement is not enough when it comes to infrastructure considerations and especially with regards to extenders.

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