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公开(公告)号：EP1649310A4
公开(公告)日：2009-04-08
申请号：EP04777428
申请日：2004-07-02
发明人： VOKEY DAVID E , BRIDGES MARK K , MURPHY CARY R
CPC分类号： H04B10/0771 , G02B6/262 , G02B6/4469
摘要： A method and system of intrusion detection for a multimode fiber optic cable (12). A signal is launched into the cable (12) to establish a narrow spectral width, under-filled non-uniform mode field power distribution in the cable (12). A small portion of the higher order signal modes arriving at the remote end (28) of the cable (12) is sampled and monitored for transient changes in the mode field power distribution, which changes with physical disturbance of the cable (12). When changes characteristic of fiber intrusion are detected, an alarm activates. Attempt to access optical fibers in a communication cable can be sensed and alarmed. The active signal of a multimode optical fiber (12) is monitored for signal degradation and transient power disturbance patterns that could indicate fiber damage or physical intrusion. Using adaptive filtering, normal background disturbances from heating/cooling systems, motors, fans and other building systems can be filtered out.
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2.发明公开AN INTRUSION DETECTION SYSTEM FOR USE ON SINGLE MODE OPTICAL FIBER USING A POLARIMETER 审中-公开在单模光纤USING A旋光FOR USE入侵
公开(公告)号：EP1839401A4
公开(公告)日：2010-03-17
申请号：EP05759338
申请日：2005-06-27
发明人： MURPHY CARY R , BRIDGES MARK K , VOKEY DAVID E
CPC分类号： H04B10/85 , G02B6/276 , H04B10/071 , H04B10/532 , H04L63/1416
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