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Retrofitting your Raceways

The amount of fiber used in today’s central office facilities challenges service providers with fiber management issues. In many cases, raceways were installed to accommodate the immediate needs without a plan for future growth. These undersized raceways are now unable to adequately support the enormous amounts of fiber required for today’s telecom network systems. | Next Gen NETWORKS Retrofitting your Raceways for Additional Optical Fiber Retrofitting your Raceways for Additional Optical Fiber The amount of fiber used in today s central office facilities challenges service providers with fiber management issues. In many cases raceways were installed to accommodate the immediate needs without a plan for future growth. These undersized raceways are now unable to adequately support the enormous amounts of fiber required for today s telecom network systems. A typical switch room today consists of 12-inch raceways in the main aisles with six-inch raceways used for intermediate line-ups. As more fiber is added pile-ups occur - sometimes as deep as four inches or more. The Telcordia standard GR-449 states the cable buildup of fiber jumpers should never exceed two inches in depth at any point within the fiber protection system. This paper will address the issues regarding fiber buildup in raceways and provide retrofitting solutions that can alleviate potential problems resulting from too much fiber in too little space. Motivation to retrofit The fiber running directly over the fiber distribution frames is typically where raceway retrofitting is most necessary. As fiber counts increase more patch cords are running across these raceways increasing the need for a higher capacity infrastructure. For example a five-frame line-up might require 1 000 patch cords per frame so capacity would be needed to accommodate 5 000 patch cords overhead. This may seem like simple math but the simple truth is that either service providers don t believe they will ever need five full frames of fiber or they somehow misjudge the size of the raceway for accommodating growth in the fiber. Service providers often base raceway size on their day one requirement of one frame hoping they will have enough space for growth in the raceway and save on initial costs. In reality not planning for longterm growth becomes more expensive when the need arises for retrofitting