Abstract: A system and method for remotely restoring inoperative data communications are disclosed, which causes the transmitter to transmit over the physical link a predetermined sequence of signals that can be detected at the receiver. Responsive to the detected sequence of signals, the receiver can initiate an internal reset command to restore the communication of data. As one example, a system for remotely restoring inoperative data communications is disclosed, which includes a first laser transceiver unit located in a head end, and a second laser transceiver unit remotely located in a node end, and an optical transmission medium connected between the head end and the node end. For this example, the head end is the host end of a distributed base station system for a cellular radiotelephone network, the node end includes the cellular transmitter/receiver (remote radio head) and antenna components, and the optical transmission medium is a fiber optic cable.

Abstract: Systems and methods for forward error correction in wideband digital RF transport systems is provided. In one embodiment, a method for transmitting digital data in a wideband digital RF transport system is provided. The method comprises receiving a first digital signal, wherein the digital signal includes a stream of digital RF packets, each digital RF packet comprising one or more data samples representing a digitized wideband RF spectrum; encoding error correction data into the stream of digital RF packets based on an error correction algorithm to produce a stream of modified packets; and transmitting a second digital signal comprised of the stream of modified packets via a communications medium.

Abstract: Methods and systems for controlling power in a communications network are provided. In one embodiment, a method comprises reading a power level of a communication link; and, driving an attenuation control signal based on the power level of the communication link. When the power level is greater than or equal to a minimum supported power level, driving an attenuation control signal further comprises constraining the attenuation control signal to a calibrated range of a characteristic curve. When one or both of the power level is less than the minimum supported power level and a bit error rate is greater than a maximum error threshold, driving an attenuation control signal further comprises generating an attenuation control signal outside the calibrated range of the characteristic curve.

Abstract: A system to monitor gain in a broadband radio frequency transport system that includes a radio frequency antenna, a remote unit, and a host unit adapted to receive a signal from the remote unit over a transmission link. The remote unit includes a pilot tone generator adapted to generate at least one single-frequency tone having a known power level, a summing circuit operably associated with the pilot tone generator adapted to sum the single-frequency tone with the respective received radio frequency signal. Each host unit includes a pilot tone receiver circuit to receive the transmitted signal and detect the single-frequency tone transmitted over the transmission link. The host unit includes a controller to determine a gain within the transmission link and to determine if the gain is in a preset range of gains based on the power level of the received pilot tone.

Abstract: Methods and systems for controlling optical power attenuation are provided. A method comprises periodically measuring an optical power of an optical signal received by an optical receiver and periodically measuring a first attenuation control signal voltage. When the optical power measurement is outside a target power range, the method continues with calculating a target voltage necessary to maintain the optical power measurements at a target power level; calculating a second attenuation control signal based on the target voltage, wherein the second attenuation control signal is calculated to provide an over-damped transient response that maintains the second attenuation control signal within a usable range of a variable optical power attenuator; applying a second attenuation control signal voltage based on the second attenuation control signal to the variable optical power attenuator; and adjusting attenuation of the optical signal based on the second attenuation control signal voltage.

Abstract: Methods and systems for controlling optical power levels in an optical communications network are provided. In one embodiment, a system comprises means for demodulating one or more radio frequency communications signals from a modulated optical signal, wherein the means for demodulating measures an optical power level of the modulated optical signal; means for comparing the measured optical power level to one or more reference set points; means for transmitting a feedback signal, wherein the feedback signal is based on the difference between the measured optical power level and the one or more reference set points; and means for attenuating the modulated optical signal based on the feedback signal.

Abstract: A method of upgrading the system capability of a communications network is provided. The method involves initiating a transfer of at least one set of upgraded system capability software machine-coded instructions to a host card, instructing the host card to begin an upgrade process, determining whether at least one set of system capability software machine-coded instructions on the host card is valid, and completing the transfer of at least one valid set of system capability software machine-coded instructions to the host card, wherein the system capability is upgraded without affecting operation of the network.

Abstract: A device with a multi-function test feature for assessing or directing multiple sensor functions is provided for monitoring and interrogating air flow through Heating/Ventilation/Air-conditioning (HVAC)-type ducts for changes to ambient conditions such as smoke, heat, gas, and/or relative humidity.

Abstract: A device with a multi-function test feature for assessing or directing multiple sensor functions is provided for monitoring and interrogating air flow through Heating/Ventilation/Air-conditioning (HVAC)-type ducts for changes to ambient conditions such as smoke, heat, gas, and/or relative humidity.