North Carolina’s Research Triangle is renowned for solving mysteries, specifically technical ones. That’s what occurs when three tier-one research universities – N . C . State University (NCSU), Duke, and also the University of North Carolina (UNC) at Chapel Hill – and cutting-edge tech companies like Fibers in stainless steel tube are inside 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 very long every commercial data center in the world will have portions of its fiber-optic network migrated to 40Gb/s or 100Gb/s to remain competitive business-wise. Finding the paper The Optical Fiber Ribbon Solution for that 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 comes into play because OM3 and OM4 – the only real multi-mode fibers within the 802.3ba standard – use parallel-optic transmission. According to an article about the Cabling Installation & Maintenance site which means by design optical/electronic interfaces allow data to get transmitted and received over multiple fibers. Additionally, it means 40G Ethernet interfaces comprise of four 10G channels on four fibers per direction, and 100G Ethernet interfaces use four 25G channels on SZ stranding line per direction as shown inside the diagram below.
Bottom line: parallel runs are utilized to increase throughput bandwidth using either multiple fiber-optic cables or multiple fibers inside a ribbon cable. To the point of employing a ribbon cable over individual cables Charuk writes, “The usage of ribbons enable easier connectorization (less possibility to cross fibers in a MPO connector), dexkpky80 perhaps moreover, achieve easier polarization continuity irrespective of the polarity method selected for that system.”
“Ribbon cables are already used in the telecom industry in excess of twenty years,” writes Charuk. “These were exposed to increase the fiber density inside a given cable as well as reduce cable costs. Of particular importance is fiber density, as fiber counts boost in the data center, it is really 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 as being most suited to both new and retrofit installations from the data center,” concludes Charuk. “Additionally, the ribbons in Sheathing line would be best suitable for future expansion, because the transmission protocols progress to higher and better data rates.”