Often when we hear the term “bandwidth” we think of how much data can be sent over a fiber link. But when we look at fiber specifications, we typically see a specification for modal bandwidth, or effective modal bandwidth (EMB). This key characteristic of multimode fiber refers to how much data a specific fiber can transmit at a given wavelength, and it is dependent on another characteristic—differential mode delay.
So you’ve finished your fiber cable installation and are now on to the task of certifying the cable plant using an optical loss test set (OLTS) – it’s the tool you need for Tier 1 certification and the most accurate for measuring loss to ensure application support.
Unfortunately, you find some critical fiber links that far exceed your loss budget for the application. You now need to troubleshoot those links so you can fix the problems and move on to your next job. And the faster you can locate the problems, the faster you can fix them.
While it seems we can never hammer home enough the need to properly clean and inspect fiber end-faces since contamination remains the number one cause of fiber link failures, have you ever thought about what exactly you are cleaning and inspecting?
It’s always interesting at trade shows to learn what’s on the minds of end users, designers and technicians alike when it comes to testing. And this year’s BICSI Winter Conference was no different.
We’ve covered fiber insertion loss in plenty of past blogs, so by now we hope that you know it’s the amount of signal loss that occurs as the signal travels along a cable link. We also hope you know that insertion loss is directly related to the length of the cable—the longer the cable, the greater the loss—and that any connection point along the way (connectors, splices, splitters, etc.) also adds to the loss.
High speed applications are driving the deployment of multifiber MPO/MTP architectures in the data center, and it’s not just cloud and hyperscale data centers that are deploying these solutions. As the de facto interface for 40 Gig and 100 Gig switch-to-switch backbone data center applications that use parallel optics, MPO/MTP links are rapidly becoming commonplace in today’s enterprise data centers.
A passive optical LAN, also sometimes referred to as simply a passive optical network (PON), is a point-to-multipoint architecture that used passive optical splitters to split optical transmission signals from a single strand of singlemode fiber into multiple outputs. The technology has gained wide acceptance in outside plant applications, and it is now gaining traction in premise applications—especially in government and hospitality markets.
Driven by the NBASE-T Alliance and compatible with the NBASE-T specification, IEEE 802.3bz specifies 2.5 Gbps over 100 meters of Category 5e cabling or 5 Gbps over 100 meters of Category 6 cabling. It also includes support for 5 Gbps over Category 5e on defined use cases (extended frequencies).
To properly send data over fiber cable, a link’s transmit signal (Tx) at one end of the cable must match the corresponding receiver (Rx) at the other end. And the role of polarity, which defines the direction that the signal travels, is to make sure that this correspondence is maintained. Fiber polarity is one area that seems to cause a lot of confusion in our industry – especially when it comes to multifiber MPO solutions used in parallel optic applications.