WHITE PAPER Wireless Switching Office Fiber Cable Management The Advantage of Wireless Switching Office Fiber Cable Management Fiber is on the increase within wireless switching centers as they evolve to meet rising bandwidth demand, requiring modifications to the traditional wireless switching office. With any increase in fiber, developing and maintaining good fiber cable management quickly becomes an important consideration. As wireless switching centers – we’ll refer to them as mobile switching centers (MSCs) in this paper – are being retrofitted to increase density and capability, a good fiber cable management system ensures quality-of-service is maintained. With many years of experience in many unique situations, ADC has long been preaching the message of proper cable management techniques – and the company’s products reflect the same philosophy. That message is becoming more applicable in today’s wireless world. With much more fiber and copper cabling being required in MSCs, cable management has become a critical issue. Any high-density distribution frame must be functionally designed to accommodate the large numbers of incoming and outgoing cables and patch cords. ADC’s four elements of fiber cable management – bend radius protection, cable routing paths, cable access, and physical protection – are absolutely applicable in today’s wireless MSCs. The differences between an MSC, a typical central office (CO), large enterprise data centers, and even a cable television environment are beginning to blur. With those lines blurring and competition among the different service providers intensifying, maintaining a good cable management system becomes much more critical for maintaining QoS and a competitive advantage. Blurring the lines Convergence within an MSC basically refers to the migration from packet switching to Internet protocol (IP) switching. Since this is taking place at the active equipment level to achieve standardized data transmission, the physical architecture between a multiple service operator (MSO), regional Bell operating company (RBOC), large data center, and wireless operator is becoming very similar. Page 3 Wireless operators have experienced tremendous growth in the last few years, creating an almost chaotic environment in which upgrading and building new MSCs has taken on a sense of urgency. Unprepared for such rapid growth, many wireless providers are racing to meet capability goals without giving much thought to future- proofing their network – particularly within the MSC. In other words, the emphasis is typically on meeting the “now” without worrying about the “tomorrow.” This could be a costly business strategy when it comes time for any future upgrades. For example, during the initial installation of a high density optical distribution frame (ODF) line-up in an MSC, a service provider may install only two or three frames at first, planning for more in the future. A six-inch overhead. A six-inch overhead raceway may provide adequate capacity to handle in-coming patch cords. However, as the addition of more ODF’s becomes necessary, the six-inch raceway will lack the capacity to adequately service the additional frames. Installing 24-inch raceways from the beginning will enable enough patch cord capacity for additional ODFs without a complete overhaul. In other words, saving initial costs by using smaller, less expensive raceways in the beginning is only deferring future retrofit costs that will likely be much higher in terms of product, time, and manpower. ADC data suggests those retrofit costs could be two to three times the cost of the original raceways to handle additional cabling. Future-proofing the raceways will eliminate the operational risk incurred by physically handling all the fiber. Value-added modules A second significant issue facing wireless operators is the ability to monitor fiber traffic. As wireless carriers migrate to universal mobile telecommunication system (UMTS) or 3G technologies, much of their traditional copper-based network is transitioning to fiber. Using copper gave them circuit access through a digital signal cross-connect (DSX), which enabled them to simply plug in a portable test set and non-intrusively monitor traffic over the network. However, much of the UMTS active equipment lacks that type of access. To compensate, many UMTS operators are electing to use Value-Added Modules (VAMs). These are basically optical 90/10 splitters that provide access for monitoring traffic by leveraging an overhead signal on the network. At the same time, VAMs provide easy demarcation points. As other fixed-line carriers connect to the network, the VAM peels off 10% of the signal onto one output and the other 90% continues down the network through the other output. At demarcation points, the VAMs clearly identify where the signal is being handed off and who is responsible for the physical plant from that point on. In the event of a problem, technicians can proceed directly to the demarcation point and non-intrusively observe both directions to determine if the problem is on their end or the other carrier’s end. The VAM segments the network and provides faster troubleshooting and maintenance capability, as well as allowing for quicker assignment of responsibility. Elements of cable management Maintaining QoS standards in wireless MSCs requires adhering to the same elements of cable management found in an efficient wireline CO. The migration of MSCs to a primarily fiber environment requires wireless operators to utilize functional high-density optical distribution frames that address good cable management for quick and efficient turn-up, test, and reconfiguration. The first element is to employ proper bend radius protection, ensuring the fiber runs as defined in Telcordia GR-449-CORE, Issue 2. This standard states that all fiber within the network needs to be protected with a radius of 1.5 inches or 10 times the outside diameter (OD) of the cable, whichever is greater. This protection is critical for long-term optical performance and the support of future high-speed services. Secondly, the MSC requires clear cable routing paths that allow every fiber to be followed along its particular path. As fiber counts in the MSC continue to increase, the need to easily follow cable routing paths is magnified. ADC has developed many products that make the difference between neatly routed, easily accessed patch cords and congested chaos. For example, ADC’s TracerLight ® Patch Cords provide LEDs at both ends of the cable. The technician plugs into the LED at one endd for easy and effective identification. With this technology, technicians can be absolutely certain they are removing the correct patch cord and decrease service interruptions caused by human error. Another ADC product designed for ensuring clear cable routing on the active equipment is RiserGuide. Resembling a peg board, this product can be installed next to a rack of OEM equipment to control bend radius on fiber entering and exiting the equipment. Fiber pathways can also be created vertically along the side of the active equipment rack. In the past, when about 50 fibers exited a particular cabinet, MSCs had little need to be concerned about fiber routing and management. But with tremendous increases in densities within today’s active equipment world, these racks and cabinets now use upwards of 400 or 500 fibers and patch cords – and proper routing becomes a more pressing issue. Wireless switching office fiber cable management Web Site: www.adc.com From North America, Call Toll Free: 1-800-366-3891 • Outside of North America: +1-952-938-8080 Fax: +1-952-917-3237 • For a listing of ADC’s global sales office locations, please refer to our Web site. ADC Telecommunications, Inc., P.O. Box 1101, Minneapolis, Minnesota USA 55440-1101 Specifications published here are current as of the date of publication of this document. Because we are continuously improving our products, ADC reserves the right to change specifications without prior notice. At any time, you may verify product specifications by contacting our headquarters office in Minneapolis. ADC Telecommunications, Inc. views its patent portfolio as an important corporate asset and vigorously enforces its patents. Products or features contained herein may be covered by one or more U.S. or foreign patents. An Equal Opportunity Employer 104692AE 4/07 Original © 2007 ADC Telecommunications, Inc. All Rights Reserved WHITE PAPER Thirdly, technicians must have easy access to any cable for troubleshooting, monitoring, or maintenance of the network. Tool-less access to both front and rear connectors without disturbing adjacent fibers or connectors helps accomplish this goal. The VAMs also play a critical role in enabling non-intrusive access at demarcation points and on the ODFs, The final element of proper cable management is physical security and safety. Obviously, the less each fiber or patch cord is physically moved and manipulated, the less chance of creating any physical damage problems. With proper labeling, record keeping, and routing, technicians can locate a particular cable without risking damage to another. Conclusion It cannot be overstated that new fiber-rich wireless MSCs will require good fiber cable management to enable a smooth, future-proof migration to UMTS and IP technologies. Proper care and planning will provide additional benefits to the carrier – including maximizing operational efficiency, enabling easy access, achieving high flexibility, and lowering the total cost. ADC’s complete line of cable management products has been perfected over years of field testing in facilities worldwide. Constant innovation and successful implementation has earned ADC a reputation as the “go-to guys” of end-to-end cable management. For the wireless carriers, this equates to an MSC that will serve the network well into the future. WHITE PAPER . PAPER Wireless Switching Office Fiber Cable Management The Advantage of Wireless Switching Office Fiber Cable Management Fiber is on the increase within wireless. within wireless switching centers as they evolve to meet rising bandwidth demand, requiring modifications to the traditional wireless switching office.