North Carolina’s Research Triangle is known for solving mysteries, in particular technical ones. That’s what occurs when three tier-one research universities – North Carolina State University (NCSU), Duke, and also the University of N . C . (UNC) at Chapel Hill – and cutting-edge tech companies including secondary coating line are in the triangle.
I ran across SEL while researching IEEE’s 802.3ba 40Gb/s and 100Gb/s Ethernet fiber-optic standard. Why was I putting myself through that? Well, before too long every commercial data center on this planet may have areas of its fiber-optic network migrated to 40Gb/s or 100Gb/s to be competitive business-wise. Seeking the paper The Optical Fiber Ribbon Solution for the 10G to 40/100G Migration (PDF) created by SEL’s Bill Charuk, product manager, data center solutions, was especially fortuitous, as it answered several perplexing questions.
Ribbon-style cabling is necessary because OM3 and OM4 – really the only multi-mode fibers within the 802.3ba standard – use parallel-optic transmission. According to an article in the Cabling Installation & Maintenance site this means by design optical/electronic interfaces allow data to get transmitted and received over multiple fibers. Furthermore, it means 40G Ethernet interfaces include four 10G channels on four fibers per direction, and 100G Ethernet interfaces use four 25G channels on optical fiber ribbon machine per direction as shown in the diagram below.
Financial well being: parallel runs are used to increase throughput bandwidth using either multiple fiber-optic cables or multiple fibers in the ribbon cable. To begin employing a ribbon cable over individual cables Charuk writes, “Using ribbons provide for easier connectorization (less ability to cross fibers within an MPO connector), dexkpky80 perhaps most importantly, achieve easier polarization continuity no matter the polarity method selected for your system.”
“Ribbon cables have been employed in the telecom industry for more than 2 decades,” writes Charuk. “These folks were exposed to improve the fiber density in the given cable and to reduce cable costs. Of particular importance is fiber density, as fiber counts boost in the information center, it is an attractive feature.”
Fiber-optic ribbon cables look like a logical choice. “The complete mixture of ruggedness from the ribbon design, fiber density, size, and relative cost points to ribbon for being best suited to both new and retrofit installations inside the data center,” concludes Charuk. “Additionally, the ribbons in secondary coating line would be best suitable for future expansion, because the transmission protocols progress to higher and higher data rates.”