Abstract: An infrared (IR) communication system is described in which a base unit for a cell can communicate with a plurality of infrared portable devices through distributed infrared receiver/transmitter (RT) modules over a plurality of channels using IR carrier signals. A call or signal processor, referred to as a radio exchange unit, and controlling communication of a cell, communicates with the base unit to place or receive calls with the IR portable devices. The communication occurs in standard communication frames divided into transmission and receiving segments with each segment further divided into slots and with the slots containing digital data, with each communication channel formed by a slot. Each transmission segment to an RT module is immediately followed by a responsive receiving segment.

Abstract: An infrared (IR) communication system is described in which a base unit for a cell can communicate with a plurality of infrared portable devices through distributed infrared receiver/transmitter (RT) modules over a plurality of channels using IR carrier signals. A call or signal processor, referred to as a radio exchange unit, and controlling communication of a cell, communicates with the base unit to place or receive calls with the IR portable devices. The communication occurs in standard communication frames divided into transmission and receiving segments with each segment further divided into slots and with the slots containing digital data, with each communication-channel formed by a slot. Each transmission segment to an RT module is immediately followed by a responsive receiving segment.

Abstract: An infrared (IR) article or person locator system is described wherein a plurality of stationary units are distributed in zones throughout an enclosure. The article or person carries a portable device so that the infrared communication link can derive local information as to where the article or person is and an RF link is used, instead of cables, to transfer the local information to a central processor or station. In one embodiment local stationary beacons generate location codes at an IR carrier frequency and IR portable devices carry transceivers made of an IR receiver and a portable RF transmitter transmits the location code and a PIN code associated with the portable device to the central station. Techniques are described for reducing electrical power demands on the portable device's battery while enhancing the speed with which the central station can be alerted of a change in the location of the portable device.

Abstract: An infrared (IR) communication system is described in which a base unit for a cell can communicate with a plurality of infrared portable devices through distributed infrared receiver/transmitter (RT) modules over a plurality of channels using IR carrier signals. A call processor, referred to as a radio exchange unit, and controlling communication of a cell, communicates with the base unit to place or receive calls with the IR portable devices. The communication occurs in standard communication frames divided into transmission and receiving segments with each segment further divided into slots and with the slots containing digital data, with each communication channel formed by a slot. Each transmission segment to an RT module is immediately followed by a responsive receiving segment.

Abstract: An infrared communicating badge is provided for transmitting an infrared coded signal, such as a patient identification number. The badge includes a sealed housing having an infrared transparent segment. The badge housing contains a power source, a microprocessor, an infrared transmitter, and an infrared receiver. The badge receiver is desensitized such that it does not respond to ambient light from the surroundings and, preferably, only detects signals from a programmer. This programmer transmits a coded infrared signal, which represents the patient identification number, to the badge. After the coded infrared signal is transmitted and stored in the badge, the infrared signal is transmitted periodically to another infrared receiver, located in a remote location. The remote receiver relays the information to a base unit at which the location of a person may be monitored.

Abstract: A system for unintrusively determining parameters such as current, voltage and power delivered through a service line to a customer for verifying accuracy of the customer's entrance meter. The system includes a sensor apparatus for monitoring voltage and current on the power line. A voltage clamp mechanism is disposed within a sensor housing such that an insulation piercing voltage sensor can be manually actuated to pierce the electrical insulation of the power line and contact the conductor. The sensor apparatus also includes a split-core current transformer fabricated to minimize the air gap between the split-core sections when the apparatus is closed about the power line. A pole unit is electrically connected to each sensor apparatus for monitoring the voltage and current, calculating the power consumed in kilowatt-hours and storing calculated kilowatt-hours in memory with an appropriate date/time stamp, for subsequent retrieval and comparison with the customer's entrance meter readings.

Abstract: An amplitude-shift-keyed (ASK) optical transmitter is described for generating an ASK modulated infrared signal from a light-emitting-diode (LED). The transmitter includes a DC powered microcircuit for generating an ASK modulation signal. A pair of mosfet devices are connected in series with one or more LED's between the mosfets. An oscillator signal used to operate the microcircuit is also employed as a carrier signal to activate one mosfet while the ASK modulating signal is coupled to operate the other mosfet. Input capacitances of the mosfets are used to tune the oscillator signal and smooth the leading and trailing edges of the ASK modulation signal. Several embodiments are described.

Abstract: An amplitude-shift-keyed (ASK) receiver is described for use in receiving infrared ASK modulated carrier signals wherein a delayed version of a demodulated pulse os compared with a stretched version and a dynamic threshold signal to reproduce binary data pulses. The dynamic threshold signal is further compared with the stretched version to derive an indication of the amplitude of the incident optical carrier. An embodiment illustrating use of the ASK receiver in an infrared communication system is described.

Abstract: A two way communication system is described wherein a base unit can transfer information with remotely-located unit such as a portable infrared communicator. The base unit produces carrier frequency signals to a plurality of distributed transmitter modules which expose different areas to infrared transmissions. A plurality of down-link or base unit associated infrared detection modules are distributed to receive infrared carrier frequency communications from one or more remote or portable units and convert these to electrical signals at the same carrier frequencies. The latter electrical signals are delivered to the base unit through a common cable. This cable also serves to deliver electrical power to the base unit to the latter modules. The electrical carrier frequency signals are combined at the base unit which uses this to provide the base unit with the information detected from the remote unit and produce a signal representative of the detected infrared energy.

Abstract: A two way communication system is described wherein a base unit can transfer information with remotely-located unit such as a portable infrared commuicator. The base unit produces carrier frequency signals to a plurality of distributed transmitter modules which expose different areas to infrared transmissions. A plurality of down-link or base unit associated infrared detection modules are distributed to receive infrared carrier frequency communications from one or more remote or portable units and convert these to electrical signals at the same carrier frequencies. The latter electrical signals are delivered to the base unit through a common cable. This cable also serves to deliver electrical power to the base unit to the latter modules. The electrical carrier frequency signals are combined at the base unit which uses this to provide the base unit with the information detected from the remote unit and produce a signal representative of the detected infrared energy.

Abstract: A portable telephone or other signaling system features a remote or portable unit responsive to operator voice and control signals to modulate infrared emitting diodes with narrowband, FM low duty cycle pulses which are received by a telephone network unit operative to demodulate the infrared signals, control the telephone network connection and to transmit and receive voice signals from the network. The portable unit utilizes narrowband FM pulse modulation to optimize the use of battery power. The portable unit further includes means for transmitting on-and-off hook indicia and dialing pulses with the same efficient, narrowband FM pulse modulation. The network base unit includes infrared receiving and decoding means in order to identify audio signals and apply them to the telephone network as well as to detect dial pulses and on-and-off hook indicia to process them for connecting and disconnecting the network unit to the telephone network.