Issue link: https://www.e-digitaleditions.com/i/1347119
38 I ICT TODAY FIGURE 4: OSP 432-fiber GR-20 compliant LM-series singlemode micro cable, which is under a ½ inch in diameter due to the 250-micron fiber strands. 7 The following information is typical for many blown cable systems: A key distinction between traditional cabling and blown cabling is that the initial installation of the micro duct infrastructure is the only time that there will be physical disruption to the OSP and buildings for optical fiber projects. Because it takes only two installers to blow micro cables behind the scenes in telecom rooms, for example, there is no need to ever re-enter the micro duct infrastructure, walls, or ceilings. With the physically nondisruptive blown cable system, upgrades, any moves, adds, or changes (MACs), fiber path rerouting and other fiber-related projects can be done anywhere and at any time, discreetly out of view of employees and visitors. One of the major benefits of adopting a blown cable system is the typical 2-installer installation, which can save significant time and labor costs. For example, to add a new fiber run approximately 3,000 feet (915 m) in an already laid micro duct infrastructure, it generally would take two installers approximately 30 minutes to blow the micro cables at a typical speed of 150 feet (46 m) per minute. This would require four or more installers taking many hours or possibly a day to pull the optical fiber cable. Because any type and count of micro cables can be blown in and out of the modular and reusable duct infrastructure undamaged, there is no end to the fiber and bandwidth life cycles. Some blown fiber systems may make the above claims as well. For its blown cable system, the US33 SMC decision makers chose an air-jet solution with a 7-way duct (Figure 3) for ease of installation and significant scal- ability with a capacity of up to 3,024 fiber strands when using the selected 432-fiber count OSP non-armored singlemode micro cable (Figure 4). For additional information about OSP blowing instal- lation technologies and comprehensive best practices for all outdoor installs, refer to BICSI's Outside Plant Design Reference Manual (OSPDRM), 6th Edition. FIGURE 3: (A) Shown is the 7-way duct, consisting of 7 individual micro ducts (22 mm outer diameter, 16 mm inside diameter) bundled under one over-sheath used in the US33 SMC project. It replaces the need for installing traditional conduit and innerduct used in traditional cable pulling. (B) 2-way, 4-way, 7-way, 19-way, and 24-way micro duct configurations are available. 6 A B