Abstract: An optical switch assembly includes a first member, a second member movably secured to the first member, and first and second optical cable connectors attached to the first member. The second member is movable between first and second positions relative to the first member. The optical switch assembly also includes an optical cable having opposite first and second ends. The optical cable first end is in optical communication with the first optical cable connector and the optical cable second end is attached to the second member. Movement of the second member to the second position causes the optical cable second end to be in optical communication with the second optical cable connector such that an optical path is established between the first and second optical cable connectors. The establishment of an optical path allows the optical cable to pass an optical signal back to a monitoring station.

Abstract: A remote door access monitoring system includes a central monitoring component and a remote monitoring component. The central monitoring component includes an optical source, an optical power level receiver, and a microcontroller. The optical power level receiver is in communication with the microcontroller. The remote monitoring component includes an optical switch that is operably associated with a door of a communications equipment cabinet. The communications equipment cabinet is located at a geographical location different from a geographical location of the central monitoring component. The optical source transmits an optical signal from the optical source to the optical switch and back to the optical power level receiver. The optical switch attenuates the optical signal in response to opening and closing of the door. The optical power level receiver is configured to detect an attenuated optical signal and then notify the microcontroller of the existence of an attenuated optical signal.

Abstract: A remote door access monitoring system includes a central monitoring component and a remote monitoring component. The central monitoring component includes an optical source, an optical power level receiver, and a microcontroller. The optical power level receiver is in communication with the microcontroller. The remote monitoring component includes an optical switch that is operably associated with a door of a communications equipment cabinet. The communications equipment cabinet is located at a geographical location different from a geographical location of the central monitoring component. The optical source transmits an optical signal from the optical source to the optical switch and back to the optical power level receiver. The optical switch attenuates the optical signal in response to opening and closing of the door. The optical power level receiver is configured to detect an attenuated optical signal and then notify the microcontroller of the existence of an attenuated optical signal.

Abstract: A demodulator for demodulating a received signal which has been modulated in accordance with a modulation scheme which falls within the class of APK modulation. The demodulator uses a phase locked loop (PLL) to recover the carrier. A ROM in the demodulator provides information in both the sweep and locked modes of operation of the PLL to control the PLL. The ROM also provides at its output the digital data which has been encoded at the modulator in accordance with the selected APK scheme. The information stored in the ROM is uniquely determined by the signal points associated with the selected scheme. A modulator for generating the modulated signal received by the demodulator is also disclosed.