Optical fiber applications in CCTV systems

CCTV consists in the installation of cameras on strategical places and the observation of transmitted images in monitors that could be anywhere from 3ft to 600ft away. It is an important part of almost every security system since it is used to watch over high-secure facilities or monitoring traffic, therefore camera links need to be difficult to tap and immune to any electrical interference.

Optical fiber offers several advantages over other cable systems such as copper or UTP:

Longer distances: While copper cables are effective for maintaining image quality for just 300ft, optical fiber transmission works for distances up to 37 miles.

Bandwidth: Optical fibers have greater bandwidth than other cable systems, which gives the user the ability of connecting several cameras to the same backbone.

Data safety: Although it is possible to hack optical fibers, it is really hard to do it without being detected, so the possibility of hackers decoding the images is minimized. Also, optical fibers do not conduct electricity, so there is no risk of ground loops or lighting strikes.

High resolution pictures: Pictures transmitted over optical fiber achieve high qualities due to fiber great bandwidth, fast data transmission and immunity to electromagnetic interference.

Reliability: Optical fiber cables are resistant to chemical exposure, humidity and temperature changes, so they can be installed in places no other cables could.

Lower cost: Optical fiber is known to be future-proof because it can be upgraded by changing the technology that creates the electronic light pulses, instead of replacing the cables. Also, materials are unlikely to degrade in a short time, so maintenance cost are reduced.

Choosing the devices

Optical fiber cables

The type of fiber is determined by the transmission distance and whether it is going to be used in indoor or outdoor applications. There are two different types of optical fiber, multimode and single mode. Multimode fiber has a 50 to 62.5 microns core and is widely used to connect telecommunication rooms within campus buildings. Single mode micron’s measures 9 microns and is used in long distance applications.

If you want to keep reading the difference between multimode and single mode, you can read the article we wrote on the subject here.

Active components

When selecting the active components of your network, you have to consider the type of signal. Analog CCTV signals are transmitted and received over analog converters, while IP ones need Ethernet media converters. The number of video signals also determines the selection of the devices with the suitable number of inputs.

According to the guide Evolving and Optimizing Security and Surveillance Systems, these are some of the devices that can be used:

Analog CCTV

Analog transmitters and receivers: Analog transmitters allow video signals to be transferred on a strand of single mode or multimode fiber up to about 6 miles. Receivers convert optical signals back to analog video signals. Transmitters and receivers can be combined into transceivers.

Analog video media converters: They are an inexpensive method to incorporate optical fiber into coaxial networks in order to improve quality and coverage. Converters connect devices with copper ports to equipment with fiber ports and change video signals on copper cables to optical fiber. 

IP CCTV

Ethernet media converters: They are used to connect equipment with Ethernet copper ports to devices with fiber ports. Ethernet media converters change IP video signals on UTP to optical fiber.

Power over Ethernet media converters: Besides changing IP video signals on UTP to optical fiber, they insert energy to power remote cameras. 

Connectors

Connectors must be selected according to manufacturer instructions. An article published in Cabling Installation and Maintenance says the patch cords used to interconnect security equipment to optical fiber links are usually terminated with an SC connector on one end and ST or LC at the other end.

Optical fiber has an outstanding performance in many fields, from telecommunication to surveillance it is proven to be the leading technology.

January 05, 2016 by

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