Abstract: An optical line terminal (OLT) performs power management control in a passive optical network (PON) by acquiring a respective reception level for each optical network unit (ONU) in the PON and maintaining a reception table that stores the respective reception level for each ONU. Prior to receiving a burst signal from an ONU, it sets a reception threshold of an optical receiver at the OLT with the reception level of the ONU.

Abstract: An apparatus including a writing surface, such as a whiteboard, is configured to accept various elements of an electronic transcription system. In one embodiment of the invention, a writing surface, such as a whiteboard or other writing surface, includes an aperture adapted to accept a transducer of the transcription system.

Abstract: Methods and apparatus for using ultrasound to measure speed and acceleration in fluids is provided. Three exemplary embodiments are disclosed. The first exemplary embodiment measures fluid velocity, such as, for example, wind, under standard atmospheric pressure-temperature. The second exemplary embodiment measures gas velocity, such as, for example, wind, affected by and automatically calibrates for pressure-temperature. The third exemplary embodiment measures gas density, such as, for example, density altitude. Applications of the invention include wind direction and speed calculation in agriculture, aviation, hydraulics, and other industries. One of the advantages provided by the invention is there are no moving parts in making such measurements.

Abstract: An apparatus including a writing surface, such as a whiteboard, is configured to accept various elements of an electronic transcription system. In one embodiment of the invention, a writing surface, such as a whiteboard or other writing surface, includes an aperture adapted to accept a transducer of the transcription system.

Abstract: Methods and apparatus for using ultrasound to measure speed and acceleration in fluids is provided. Three exemplary embodiments are disclosed. The first exemplary embodiment measures fluid velocity, such as, for example, wind, under standard atmospheric pressure-temperature. The second exemplary embodiment measures gas velocity, such as, for example, wind, affected by and automatically calibrates for pressure-temperature. The third exemplary embodiment measures gas density, such as, for example, density altitude. Applications of the invention include wind direction and speed calculation in agriculture, aviation, hydraulics, and other industries. One of the advantages provided by the invention is there are no moving parts in making such measurements.

Abstract: An apparatus and process for using ultrasound to measure speed and acceleration in fluids is provided. Three preferred embodiments are disclosed. The first preferred embodiment measures fluid velocity, such as, for example, wind, under standard atmospheric pressure-temperature. The second preferred embodiment measures gas velocity, such as, for example, wind, affected by and automatically calibrates for pressure-temperature. The third preferred embodiment measures gas density, such as, for example, density altitude. Applications of the invention include wind direction and speed calculation in agriculture, aviation, hydraulics, and other industries. One of the advantages provided by the invention is there are no moving parts in making such measurements.

Abstract: A transmitter pen location system is provided, in which a pen is adapted to send a repeated output signal to external receivers at two or more receiver locations, wherein the location of the pointing tip of the pen is determined in relation to the writing surface of a whiteboard. In one embodiment an output element, preferably an ultrasonic transducer, transmits a time dependent output signal from a single signal transmitter pen to two or more external receivers at two or more receiver locations. The direction of arrival of the output signal to each of the receiver locations is determined, and the pointing tip of the single transmitter pen is then determined, as the intersection of direction vectors from the pen to the external receivers.

Abstract: A transmitter pen positioning system is provided, in which a pen, having multiple output elements, is used to accurately determine the location of the pointing tip of the pen, in relation to the writing area of a surface, such as a white board. The first output element, preferably an infrared transducer, transmits a first output signal from the transmitter pen. The second output element, preferably an ultrasonic transducer, transmits a second output signal, having a lower propagation velocity than the first output signal, from the transmitter pen to two or more receivers. In a basic embodiment, the first output signal arrives at one or more receivers generally concurrently.

Abstract: A transmitter pen positioning system is provided, in which a pen, having multiple output elements, is used to accurately determine the location of the pointing tip of the pen, in relation to the writing area of a surface, such as a white board. The first output element, preferably an infrared transducer, transmits a first output signal from the transmitter pen. The second output element, preferably an ultrasonic transducer, transmits a second output signal, having a lower propagation velocity than the first output signal, from the transmitter pen to two or more receivers. In a basic embodiment, the first output signal arrives at one or more receivers generally concurrently.

Abstract: A pen positioning system is provided, in which a pen, having multiple output elements, is adapted to accurately determine the location of the pointing tip of the pen, in relation to an electronic tablet. The output elements, preferably ultrasonic transmitters having distinct frequencies, are located a fixed distance from each other, and are also related in space to the pointing tip of the pen. The geometric relationship between the output elements and the pointing tip of the pen allows the location of the pointing tip to be determined, independent of the angle which the pen is inclined against the surface of the writing tablet. A detection system is used to receive the output signals from the output elements, isolate the output signals from each other, and process them independently to determine the location of the output elements and of the pointing tip of the pen.

Abstract: A transducer signal waveshaping system is provided, in which a signal excitation circuit includes a non-linear device. The resulting circuit produces a short input pulse, which allows a piezoelectric transducer to transmit a shortened output signal having distinct waveshape characteristics. The resulting waveshaped output signal, typically an ultrasonic signal, provides a measurable time-dependent signal that is particularly suited for data entry systems, such as for movable transmitter pens and white boards. The location of the transmitter pen in relation to the writing area of a white board can be determined, using the periodic transmission of the waveshaped output signals. Alternative embodiments include additional circuit elements, which allow the resulting waveshaped output signal to include even more distinctive waveform features.