Abstract: A satellite based paging communication system comprises a plurality of terrestrial stations capable of communicating the paging information with at least one satellite. The satellite(s), in turn, are capable of communicating the paging information to at least one terrestrial receiver or terrestrial station. Also included is at least one control station for determining where and how to deliver the paging information to one or more of a plurality of terrestrial receivers (pagers), at least some of which are capable of receiving the paging information from one or more of the satellites and one or more of the terrestrial stations.
February 8, 1993
Date of Patent:
April 5, 1994
Robert J. Schwendeman, William J. Kuznicki
Abstract: An automatic output power controller controls signals output by an amplifier amplifying a modulated wave with its envelope varying due to the modulation so that the mean power becomes constant. An equi-output point extraction circuit extracts timing of the output power of the amplifier becoming a constant value from a base band signal or the like, and supplies the timing to a sample-and-hold circuit. The sample-and-hold circuit samples and holds the output power. Difference between the sample-and-hold value and the reference value is supplied to an output power adjusting circuit, and the output power adjusting circuit controls signals output by the amplifier in accordance with the difference so that the mean power becomes constant.
Abstract: An FM intermediate-frequency circuit into which there is integrated at least a limiter-amplifier (1A) and a phase-locked loop which contains a VCO (4). The limiter-amplifier also includes a level detector. The dynamic range of the level detector is expanded without having to use excessive limiter-amplifier amplification, which would cause oscillation problems, by placing in parallel with the limiter-amplifier (1A) at least a second limiter-amplifier (1B), in connection with which there is also a level detector. The level of the input signal of the second limiter-amplifier (1B) is dropped as compared with that of the first limiter-amplifier (1A) by means of a dividing circuit (R1, R2). The signals (1A, 1B) obtained from the level detectors are combined to form one level detection signal (ITOT). If the signals are in the form of current, the combining can be carried out directly by summing the signals.
Abstract: This device is intended for the coupling to a same antenna of at least two devices for transmitting and/or receiving microwave frequency signals operating in a same frequency range but having separated working bands. It is constituted by a circuit (M) comprising four passive filters (F.sub.1 -F.sub.4) and two circulators (C.sub.1, C.sub.2) defining four channels for respectively coupling each of the transmitters (E.sub.A, E.sub.B) and receivers (R.sub.A, R.sub.B) of the two devices (A, B) to the antenna. Each circulator (C.sub.1 ; C.sub.2) is connected by the intermediary of a filter to the transmitter of one of the devices and to the receiver of the other device in order to couple them to the antenna, while isolating them from each other. The invention has an application for coupling transmitting and/or receiving devices installed in aircrafts.
Abstract: The network of the inventnion, of the type with star cabling, comprises a distribution center to which are connected by cable subscribers each having a remote control unit. The center comprises a video bus connected to the various program sources, this bus being connected to selection modules (M1 to MN) the number of which is equal to that of the subscribers and which are remotely controlled by these subscribers. A microcomputer monitors the legality of the connections established.
Abstract: In a cellular system, including at least one cell site located within a corresponding geographic sector, an apparatus and method provides for expanding cellular system capacity through subdivision of the geographic sector by use of a cell site transceiver and a remote site transceiver to extend said cell site to a remote location within said geographic sector. Each transceiver provides duplex operation and includes a cellular band transmitter and receiver portion for local communication with the cell site or remote site mobile units, as the case may be; and a link frequency transmitter and receiver portion for communicating cellular band information, after conversion to an appropriate baseband frequency, between the cell site and the remote site transceivers.
Abstract: A digital, interactive communication system designed to provide a plurality of remote subscribers with any one of a variety of stored information service software packages through the use of a home computing assembly maintained within the subscriber's home and structured to display video as well as generating audio on a standard television receiver. A bi-directional communication link is established over telephone lines between the home computing assembly and a central remote information storage center wherein a selected one of the variety of information services is transmitted as a modulated carrier to the subscriber. Information service selection is controlled by a remote information storage center executive software program. Automatic billing is performed by computing equipment maintained in the remote information storage center and transmitted to a headquarters which also receives diagnostic messages associated with the remote information center and/or the associated plurality of home computing elements.
Abstract: A noise blanker is disclosed which blanks out impulse noise emanating from the alternator, ignition systems of motor vehicles, and other sources. This is accomplished by delaying an input IF signal while generating a blanking gate pulse occurring at the same time as the noise pulses. These blanking pulses are then used to turn off the delayed IF signal precisely where the noise occurs, resulting in noise-free audio reception. The noise blanker operates to detect noise pulses by detecting the leading edge of any narrow pulse which is received at the front end of the receiver and is reflected in the IF input signal. At the same time, by virtue of the operation of an AGC amplifier the noise blanker's vulnerability to interference or capture by continuous-wave signals is reduced.
Abstract: According to the invention, the power and weight of a radio telephone can be modified by connecting the same basic unit (1) a desired power unit (2 or 4). The signals received and transmitted between the units (1 and 2 or 4) pass apart from each other.
Abstract: A receiver capable of receiving a plurality of signals, wherein more of the signals are received at a peak time than at an off peak time, comprises the method of a first step for determining if the signals are being received by searching in a first search mode and a second step for determining if the signals are not being received by searching in a second search mode. Selection circuitry activates the first step during the peak time and activates the second step during the off peak time. The first and second search modes comprise searching for the signal and searching for noise, respectively.
Abstract: A radio (2) having: a first memory (34) for storing first information items; memory receiving slot (18) for temporarily receiving a second memory (20, 36) for storing second items of information; microprocessor (30) for accessing both said first and second memories; and user selective transfer device (42, 44) for causing an information item from one of the memories to be transferred to the other of the memories. In a preferred form the radio is a radiotelephone, the first and second items of information are telephone numbers and the second memory is a magnetic card or a smart card.
Abstract: Radio telephone apparatus for use in a cellular mobile telephone system includes an alarm to inform a user of a drop in signal strength of radio frequency signals received over an established communication link. Such a drop occurs, for example, when the user is approaching the boundary of a service area. Further, the mobile unit detect the presence or strength of a tone signal modulated on at least one of the received radio signals. The mobile unit disconnects the telephone link and returns to the standby mode if the tone signal is lost or becomes too weak.
Abstract: A repeater (30) is provided for relaying communication between a subscriber unit (24) and a central station (10) when the repeater recognizes transmission from the subscriber unit to the central station but detects a lack of response by the central station to that subscriber unit or when the repeater recognizes a transmission from a subscriber unit (26) requesting the repeater for service. The repeater asks the central station for a channel upon which to communicate. Alternately, a predetermined channel may be used for the relayed communication.
Abstract: A global communications system is described having terrestrial transmitters for transmitting coded message signals in each of a plurality of geographic areas. The global communication system further includes at least one satellite transmitter for transmitting the coded messages signals in each of a plurality of global geographic areas. The coded message signals transmissions include channel identification codewords identifying the terrestrial channels and the satellite channel. The terretrial channel is selected for operation when the channel identification codeword received matches a first predetermined channel identification codeword. The satellite channel is selected for operation when the channel identification codeword does not match the first predetermined channel identification codeword. When the satellite channel is selected the terrestrial channel is periodically reselected to enable decoding the channel identification codeword received on the terrestrial channel.
Abstract: A method for allocating communication resources within a communication system wherein communication resources are assigned only within critical sites and within non-critical sites containing critical users. A central controller checks the critical site list for allocating communication resources within the critical sites. No communication resources are allocated within non-critical sites that contain no critical users.
Abstract: A two-way radio includes a receiver having a squelch circuit for determining if a communication channel is available. A transmitter is provided for transmitting voice messages on the channel. When the communication channel is available, voice signals are directed from a microphone to the transmitter for transmission. When the communication channel is not available, the voice signals are automatically directed to a digitizer there they are digitized. The digitized voice signals are stored in a memory for later transmission when the channel becomes available.
Abstract: A communication unit having a dynamic control resource scan list utilizes the scan list to more effectively roam from the current trunked communication system to other trunked communication systems. The scan list contains control resource information of trunked communication systems, where the control resource information is the control resources of the system and the features offered by that system.
Abstract: An interactive videotex system with distributed processing and storage of video picture information in nodes disposed throughout a cable television distribution system. The nodes are coupled to the feeder cable of the cable distribution system. Each node in the system receives a substantially identical copy of the interactive video picture information and related data from a regional processing center. The users at home televisions associated with a particular node interact directly with the video picture information in that node, rather than with the information stored in the regional processing center or some other remote location, which enables the system to quickly display photographic quality images and complex graphics, as well as sound, at the user's televisions in response to commands received by the users.
Abstract: An FM broadcast receiver includes apparatus for measuring signal quality. Signal-to-noise ratio in the received signal is determined by isolating a noise component of the received audio signal, multiplying the isolated noise component by a gain determined by received field intensity, and comparing peak amplified noise against a reference. The derived signal-to-noise ratio can be employed to stop an automatic scan tuning operation or can be employed to provide a display of received signal-to-noise ratio.
Abstract: A digital, interactive communication system designed to provide a plurality of remote subscribers with any one of a plurality of stored video games or like software packages through the use of a home computing assembly maintained within the subscriber's home and structured to display video as well as generating audio on a standard television receiver and further incorporating the ability to utilize contemporary video gaming control devices for subscriber program interaction. A bi-directional communication link is established over the telephone lines between the home computing assembly and the central remote game storage center wherein the software programs are transmitted as a modulated carrier to the subscriber. Program selection is controlled by a remote game storage center executive software program.