Fiber optics
Sep 1, 2009 12:00 PM, By Stan Moote
New 1.5Gb/s and 3Gb/s video bandwidth requirements are driving broadcasters to embrace fiber.
Shown here is a variety of physical layer optical test products. The fiber identifier (center) is a unique tool that clamps onto a fiber cable and identifies both the direction and signal presence without disconnecting the fiber. The handheld OTDR (right of center) determines fiber cabling faults. Optical power meter and visible laser source (two units on the left) are valuable tools for any technician’s kit.
Additionally, installation crews do need to know how to install fiber to ensure that it doesn't crack. You should know the cable specs for the bending radius and the crush tolerance due to too many cables on top of the fiber and, just like coax, incorrect tie-wrapping. Bending cable too sharply is the worst enemy in the optical world. When you check the cable specs, you will find the bending diameter is typically 1.5in; however, there are newer cable types that allow for bending as low as 0.6in.
Hidden benefits
Besides future-proofing your facility, increasing operational flexibility and eliminating traditional distance limitations, fiber offers a number of hidden benefits:
- Green operations
Passive splitters provide monitoring points and distribution points without using power
- Simplified digital systems timing
Fiber operates at light speeds. Electrical and optical conversions take less than 10ns, so there's no longer a need to calculate cable runs.
- Improved house sync
With fiber, the distribution of color black within your plant — or even to external buildings — is simple. Again, there are no delay issues: Simply use analog video-to-fiber converters to distribute black and tone on fiber.
- No more cable tracing nightmares
Because fiber passes visible light, you simply put on a handheld visible light source and find your lost cable in seconds. Passing visible light into a fiber can also help you find faults.
- Less noise
Fiber is immune to interference. There is no need to fight ground loops and various electromagnetic or RF noise.
- Simplified control and monitoring
Many interfaces are now available to extend Ethernet, intercoms, RS-422, etc., networks over fiber with simple I/O modules. Taking advantage of these greatly unifies your operations.
Summary
After reading through this article and seeing how simple fiber is to use, you will likely ask yourself why you have not embraced fiber before. Don't wait around until you are suddenly forced into implementing a stronger 1.5Gb/s or 3Gb/s plant. After all, your upgraded IT infrastructures demand fiber, so why not use it for video too? Consider fiber today.
Stan Moote is vice president of corporate development at Harris Broadcast Communications.
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