HDSL2/HDSL4 LoopShield ™ Feature Remote Frame Ground Detection The new HDSL2/4 Remote Frame Ground Detection (RFGD) feature provides a method for detecting whether or not a frame ground has been connected at the remote HDSL2/4 unit. Overview ADC’s HDSL2/4 line cards provide visibility of faulty or missing remote chassis frame ground connections on a real-time basis. A remote unit not connected to frame ground is susceptible to poor performance and possible damage to HDSL and other transmission equipment. This has become an increasingly critical factor in the delivery of T1 service to cell sites. Cell sites are particularly vulnerable to power surges, induction and changes in ground potential caused by RF transmission equipment and lightning strikes. By determining whether or not frame ground is connected at the remote, the RFGD feature helps the customer to avoid potential problems. The remote frame ground detection is measured at the remote line unit and status is communicated to the CO line unit where it can be viewed both locally and remotely as indicated below. User Interfaces to Remote Frame Ground Detection Feature There are four major interfaces on the system that can be used to provision the card for Remote Frame Ground Detection. RFGD can be provisioned via INTAS query, Management Card Screen, Management Card TL1, and Front-panel Craft Screens. In addition to the four interfaces below, alarms can also be seen on the front-panel character display. APPLICATION NOTE www.adc.com • +1-952-938-8080 • 1-800-366-3891 INTAS Acterna T3AS Titan DCS HDSL2 Circuit HDSL2 Remote Card Universal Chassis 220, 3192, DDM+ HDSL2 CO Card Central Office CPE Craft Menu Access Flashing LED Indication DS1 Missing Ground Chassis TL-1 Query via FDL Network Control Remote Ground Sensing Detecting Frame Grounds The remote HDSL2/4 units have hardware and software support that allow them to report the presence or absence of a frame ground connection at the remote, but not the quality of the connection. The detection of a connection to frame ground is not an exact science. To detect a connection to frame ground at the remote, the frame ground reference at the CO is used. The actual earth ground is then used as the current path between the CO and remote frame ground for detecting a closed circuit. The resistance of earth ground varies greatly with soil type, moisture content, and temperature. In addition, the distance between the CO and remote greatly affects the resistance. Because of all of these variables, it is extremely difficult to accurately detect a frame ground connection between two points separated by thousands of feet. As a result, the design accommodates a range of resistances for determining whether the remote is connected to frame ground. The remote frame ground status is available and valid at the CO only if the remote line unit is connected, the feature is enabled and the DSL loop is up and running in data mode. Summary The LoopShield HDSL2/4 RGFD feature enables wireline service providers to detect whether of not remote frame grounds are connected at remote units via several user-friendly interfaces. Using this feature to ensure remote frame grounds are connected, services providers can improve customer service by avoiding many potential problems caused by power surges and changes in ground potential to un- grounded HDSL transmission equipment. 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 1331747 7/05 Original © 2005 ADC Telecommunications, Inc. All Rights Reserved 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. APPLICATION NOTE . HDSL2/HDSL4 LoopShield ™ Feature Remote Frame Ground Detection The new HDSL2/4 Remote Frame Ground Detection (RFGD) feature provides a. unit is connected, the feature is enabled and the DSL loop is up and running in data mode. Summary The LoopShield HDSL2/4 RGFD feature enables wireline