HIGH FIBER COUNT CABLE SELECTION FOR MAJOR METROPOLITAN AREAS

摘要

Communication service providers continue to explore strategies for increasing bandwidth capacity in metropolitan areas. The three primary network architectures include the "Universal Service" ring architecture of the ILEC's, the targeted ring architecture of the CLEC's, and the "tree and branch" architecture utilized by CATV operators. One strategy to increase bandwidth capacity continues to be the installation of additional optical fiber in existing underground right-of-ways. These underground right-of-ways typically contain smaller innerducts contained in larger main ducts. In order for this strategy to remain effective, the fiber count capacity of smaller innerducts and larger main ducts must be maximized. High fiber count solutions were presented for smaller innerduct sizes from 0.75-inch to 2.00-inch, ranging from 216 to 1,728 fibers. When maximizing the fiber count in smaller innerducts it is critical to accurately determine the "cable to duct" fill ratio to determine the feasibility of installing the cables. Cable design selection should also focus on the splice point fiber count and the fiber breakdown within the cable. High fiber count solutions were also presented for larger 4.00-inch main ducts with 2,592 to 4,608 fibers utilizing traditional installation methods. With these configurations it is also critical to accurately determine the "innerduct to main duct" fill ratio along with the "cable to duct" fill ratio. Higher "cable to duct" fill ratios were also discussed for increasing the fiber count capacity of 1.00-inch ducts from 576 to 864 fibers and for 1.25-inch ducts from 864 to 1,296 fibers. Non-traditional installation methods utilizing innerducts to pull in cables were also presented with the possibility of 7,776 total fibers in a 4.00-inch main duct.