WHITE PAPER Plug and Play Splitter Architectures Drive Operational Savings After service providers decide to deploy a particular fiber-to-the-premise (FTTP) architecture, they are faced with a number of important decisions. This paper addresses one such decision that will significantly impact the network in terms of time, performance, flexibility, and cost throughout its operational life. Providers must decide how to connect the F1 optical feeder cable inputs to the splitters in the fiber distribution hubs (FDHs). There are several methods for making these connections, but selecting the best technique will provide benefits in many other areas, such as turn-up speed, dealing with customer churn, and easier maintenance and troubleshooting. Early decisions to splice Many early FTTP deployments sparked concerns about loss budgets. Since the use of connectors resulted in more loss than straight splicing, the network architects decided splicing inputs to the splitters was preferable to minimize loss. The feeder cable was brought into the cabinet and prepped into a splice area. New splitters were installed with fiber pigtails that were spliced into one of the F1 fibers. This method resulted in slightly less loss and enabled the addition of more splitters as the network grew. However, there were also a few downsides to splicing the F1 cables to the splitters. The first issue is the amount of time required to install each splitter. Splicing obviously takes considerably longer than mating two connectors. Also, splicing has an affect on the work force. Each time a new splitter is added, it requires technicians with more training and higher skill sets as well as the need to have all the specialized splicing equipment available. Not having one or the other readily available increases the time it takes to perform the task and slows down the overall deployment. Another issue created by splicing is in the initial turn-up of the cabinet. In order to test all the F1 fibers, the technician must splice pigtails for connecting each F1 input to the test equipment. A considerable amount of time can be spent during initial turn-up with splicing on pigtails and cutting them off again following testing. This could lead to testing through the splitter or not testing F1 inputs at all – neither of which is a recommended practice. Plug and Play Splitter Architectures Drive Operational Savings Plug and Play Splitter Architectures Drive Operational Savings Page 3 Testing the splitter itself requires the technician to splice a connector to the input of the splitter. So, in essence, to test both the F1 and the splitter would require breaking a splice, splicing connectors to both the F1 and the splitter, running the tests, cutting off the connectors, and re-splicing the F1 to the splitter input. This process is both time consuming and costly. Benefits of connectors Eventually, network technicians determined that there are advantages to using a connectorized approach in the FDH. They decided to add a connector onto the F1 cable that would easily connect it to the splitter input. Several factors attributed to the decision to connectorize this process. First, as volumes have increased, connector quality has improved significantly in the last few years. The loss attributed to a connection has dropped about one- tenth of a dB. Additionally, the splitters have further reduced loss characteristics. Typical loss for a splitter was traditionally about 17 dB, but that has improved to about 16.5 dB today. Together, these improvements have resulted in more budget for loss – and a good place to use some of that is in adding a connector to the splitter input. Adding a connector to the F1 provides more rapid testing of the inputs. It also helps achieve faster installation of the splitters – ADC’s splitters can be installed in less than five minutes. It eliminates time and expense involved in installing each splitter into the FDH while providing one more area for segmenting the network during troubleshooting procedures Splitter choices Once the network architect makes the choice for connectorization, there are two splitter configurations available – pigtail-and-play or plug-and-play. Although both offer substantial benefits over straight splicing, the plug-and-play has additional advantages. For example, the F1 connection requires no routing when installing the splitter. This mitigates the risk of disturbing an adjacent F1 connection when installing a new splitter. In the past, there was a potential for the technician routing the F1 to accidentally disturb an adjacent F1, which could cause a service interruption or outage for 32 customers. In many cases, the F1 can be exposed whenever a technician works on the cabinet. This allows a potential for accidental damage anytime a technician is performing a task, such as connecting an F2 cable. But with a plug-and-play splitter design, the connection is made between the F1 and the splitter simply by plugging the splitter in the backplane of the cabinet. One argument for the pigtail-and-play splitter is its ability to provide more flexibility for routing business services through the cabinet. Having a pigtail in place provides a separate patch panel for routing business services or expressing them through the cabinet. Although this is a point well taken, it may be an even better idea to have those business services and their F1 connection segregated from the residential services. Business services include several classes of service with different service level agreements associated with them – along with different revenue streams. Even in a plug-and-play scenario, there is typically a completely separate pass-through panel used for expressing business services. This method enables easy identification of a different service running on a particular cable. Finally, plug-and-play splitters also require less routing expertise than the pigtail-and- play version. That equates to less training required to perform service and maintenance at areas of the network that incorporate connectors versus splices. The goal of any FTTP buildout is to achieve the right balance between up-front initial equipment costs and the operational costs involved in long-term performance of the network. Connectors are typically more expensive than a splice in terms of initial cost. However, a connectorized FDH cabinet is one point in the network where using connectors makes sense. With the improvements in the loss characteristics of fiber-optic connectors and optical splitters, the operational cost advantages of connectorization far outweigh the initial cost savings of splicing. These operational advantages – faster turn-up, easier test access, lower training requirements, less specialized equipment, and an overall more flexible network – are only achievable with a connectorized F1 input Website: 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 website. 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 105254AE 8/07 Original © 2007 ADC Telecommunications, Inc. All Rights Reserved WHITE PAPERWHITE PAPER . practice. Plug and Play Splitter Architectures Drive Operational Savings Plug and Play Splitter Architectures Drive Operational Savings Page 3 Testing the splitter. WHITE PAPER Plug and Play Splitter Architectures Drive Operational Savings After service providers decide to deploy