Tight-buffered 900um fiber includes an additional 900um layer of hard plastic over the 250um fibers for protection.
Within the cable, several of these color-coded 900um tight buffered fibers are situated around a central strength member
and then covered with Kevlar or aramid yarn for protection, a rip cord and then the jacket.
Tight-buffered 900um fiber cable comes in various fiber counts that typically range from 2 to 144 fibers,
with larger fiber counts featuring fiber subunits of 6 or 12 fibers within the cable.
For example, a 144-fiber cable usually has twelve 12-fiber subunits while a 36-fiber cable could
have six 6-fiber subunits or three 12-fiber subunits.
From Outdoor to Indoor Applications
Generally speaking, tight-buffered 900um fiber cables are used for indoor applications, including intra-building riser and plenum applications and in the data center. Loose-tube 250um fiber cables are typically used in outside plant (OSP) applications, such as inter-building duct, aerial and direct buried installations.
While indoor/outdoor cables are popular for eliminating the need for service entrance splicing to in-building cable, OSP loose-tube 250um cabling must be terminated within 50 feet of entering a facility. To accomplish this, breakout kits are used to build the 250um cable up for protection and termination to 900um connector boots.
The problem with breakout kits is that they add additional material costs and a significant amount of labor. One option is to terminate the 250um fiber directly to 250um connector boots. This can speed network deployment in the data center and fiber-to-the-home applications.