Since the development of 40GBASE-T (IEEE 802.3bq) began a few years ago, most of us believed that the next Ethernet data center speed for twisted-pair copper cabling beyond 10 Gb/s would be 40 Gb/s.
How long are the fiber links you need to test? Is it a short 50-meter multimode data center link, a longer 550-meter backbone, or maybe even a 130-kilometer singlemode link?
With contaminated connections remaining the number one cause of insertion loss and back reflection that inhibits optical transmission and causes havoc with expensive transceivers, it’s vital that fiber end-faces at both ends of a link are visually inspected.
You’ve just finished a copper cabling installation for a customer, your DSX-5000 CableAnalyzer is properly configured and you’re ready to start testing. With a press of the “TEST” button, you’re off and running.
Link after link, the tester displays a “Pass” and you’re feeling really good about the quality workmanship of your installation.
cer·ti·fy \ˈsər-tə-ˌfī\ verb 1: to attest authoritatively 2: to officially recognize someone or something as possessing certain qualifications or meeting certain standards
qual·i·fy \ˈkwä-lə-ˌfī\ verb 1: to have the necessary skill or knowledge to do a particular job or activity 2: to have the qualifications to do something
Last week at the opening of the BICSI Conference in Las Vegas, the editors of Cabling Business Magazine announced that Versiv and LinkWare Live have each won the Cabling Installation and Maintenance Innovator’s Award. These awards recognize the most innovative projects and products in the structured cabling industry. The judging panel consisted of cabling and communications system specifiers, designers, integrators and managers with vast professional experience.
Testing structured fiber cabling to international standards such as ISO/IEC 14763-3 has been defined. In the last few years, the question of loss (attenuation) measurement uncertainty has been raised. Since 14763-3 specifies test limits, the user of the standard may need to know the amount of uncertainty in the measurement. Experts from IEC, well-versed in fiber metrology and uncertainty calculations, were requested to provide simplified guidelines, a table of sorts, that a user such as an installer might find useful.
The Telecommunications Industry Association (TIA) is committed, by formal consensus, to develop standards for the benefit of industry and is represented by hundreds of companies. While participating companies cooperate to develop standards, each have their commercial business interests to protect. Sometimes, these companies over-reach to meet their business goals. Fortunately, the TIA voting and balloting process works well as a means to check and balance sometimes rogue proposals.
Several published standards describe how to perform attenuation measurements on installed fiber optic cabling. However, no standard exists that provides guidance for testing installed fiber optic cabling terminated with MPO connectors. Currently, a technical report (TR) is being drafted that provides such testing guidance.
Developed for use in data centers and enterprise network applications with a very tight loss budget, bend insensitive multimode fiber (BIMMF) is able to withstand tighter bends with substantially less signal loss than non-BIMMF.
A BIMMF design tightly confines the higher-order modes that are more likely to escape the fiber core during bending. The design achieves this by adding a specially engineered optical “trench” between the fiber core and cladding.
TIA adopted IEC 61280-4-1, the standard defining attenuation measurements of installed multimode fiber cabling, as ANSI/TIA 526-14-C.
In IEC 61280-4-1, the encircled flux launch is defined as normative (required) for these cases and there is no intention to change requirements in the next edition:
Case 1 - 50 μm core fiber at 850 nm,
Case 2 - 50 μm core fiber at 1300 nm,
Case 3 - 62.5 μm core fiber at 850 nm,
Case 4 - 62.5 μm core fiber at 1300 nm.