Careful documentation can help Gone are the days when all fiber optic cables were the same. Most building cables had 62.5/125 micron multimode fibers for LANs or security systems, while outside plant cables were all single-mode fiber.
You get what you pay for Every fiber optic cable needs to be tested for loss with an optical loss test set (OLTS). The OLTS simulates the actual network hardware that will run on the cable so the test results will show if the network will work properly on the cable.
They can be useful—but only if used correctly There are two distinctly different fiber optic applications: premises cabling and outside plant (OSP) cabling. Premises cabling deals primarily with short multimode cables in buildings or between buildings in a campus.
You have to admire the copper cabling people for their tenacity—they never give up. In spite of hearing for the last 15 years that copper has no future, they persist in developing new technology that allows copper, like the mythical Phoenix, to rise from the ashes as strong and viable as ever.
Generally, the dark side refers to Darth Vader and other not-so-good things. Leave it to the communications industry to turn something dark into something powerfully marketable and profitable—dark fiber.
Since the fiber optic “bubble” burst a couple of years ago, employment ads for fiber optic installers have been scarce. But are real jobs still available? If so, where are they? Is the outside plant market dead? What about premises applications? What technologies are driving new installations?
Every year around Christmas, stores roll out artificial trees made with optical fibers. You know the ones—they glow and shine colored light out the ends of the branches. Who would think that these trees are made of a type of optical fiber that offers easy-to-install cheap communications links?
The Telecommunications Industry Association (TIA) is an industry organization with paying members from the communications/telecom industry. They develop minimal performance standards for cabling and related hardware and installation standards for the users/designers.
My first thought in writing this column was that the title was wrong.It should be “Why Do People Still Install Copper?” In the fiber optic business, we’ve suffered from the copper industry’s harping that fiber is fragile because it’s made of glass, hard to install and too expensive.
Whenever tests are performed on fiber optic networks, the results are displayed on a meter readout in dB. Optical loss is measured in dB while optical power is measured in dBm. Loss is a negative number (like -3.2 dB), as are most power measurements. Confused? Many fiber optic techs are too.
In outside plant fiber optic installations, every cable installed will be tested for end-to-end loss with a source and power meter and an OTDR trace will be taken of each fiber. Yet OTDRs—optical time domain reflectometers—are rarely used in premises applications. Why is that?
Look for a new fiber test bulletin (not a standard) from the Telecommunications Industry Association (TIA ) in 2003. We all know fiber is looked at as more difficult to work with, so maybe that is why a new guidance bulletin is coming out that better describes fiber testing in the field.
Two measurements of optical power required Compared to Category 5e or Category 6, fiber optics wire is easy to test. A “flashlight test” can make sure the fiber has continuity and is correctly identified.