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NSCC Executive Summary <br />CBG Communications, Inc. <br />should then perform the necessary troubleshooting to determine the cause of the problem <br />and make the correct repairs. This may include replacement or tightening of connectors <br />and the replacement of cables to name a few possible solutions. <br />• Standby Power <br />Standby power provides the system with the capability to remain operational when <br />commercial power is lost for any period of time. Comcast employs several backup power <br />methodologies, from the headend and hub to the power supplies located on the <br />distribution system in the field. <br />Comcast has large backup generators located at both the headend and hub. These are <br />designed to provide enough power to keep the headend and hub operational in the event <br />of a power outage at these locations. In addition, because there is a lagtime of several <br />seconds between the loss of power and the generator corning fully on -line, Comcast also <br />has large banks of batteries that are designed to provide power to all headend equipment <br />that operate on -48VDC while continually being recharged as normal procedure. When <br />power is lost, these battery banks will continue to provide power, without any outside <br />power, for a minimum of 8.5 hours. For all critical equipment that operates on 120VAC <br />power, Uninterruptable Power Supplies (UPS) are in place to run this equipment until the <br />back -up generators are operational. <br />Comcast has power supplies located on the distribution plant to provide power to the <br />nodes and amplifiers used in the field. These power supplies are equipped with batteries <br />that provide backup power in the event of a commercial power outage. Based on <br />information provided by Comcast, these power supplies are capable of running, without <br />commercial or other power sources, for a minimum of 6 hours. This run time will <br />increase based on lower power needs at some power supply locations. <br />Our review of Comcast's documentation does not indicate a large number of outages or <br />an overall pattern of longer than acceptable repair times when outages occur. <br />vii <br />20 <br />