Abstract: For starting a registration operation of location information of movable radio telephone sets into a subscriber's file in a line connection unit connected to radio connection devices in a mobile telephone network system after travel of each of the radio telephone sets, each radio telephone set is provided with a unit for measuring a travel amount. The radio telephone set produces a request signal for the location information registration when the travel amount measured exceeds a first threshold value. Alternatively, the radio telephone set reset the measuring unit when the travel amount measured exceeds a first threshold value and thereafter produces a request signal for the location information registration when the travel amount measured does not exceed a second threshold value smaller that the first threshold value. Radio connection devices announce location information signals and each radio telephone set holds, as a held location information, the location information registered in the subscriber's file.

Abstract: A circuit for preventing a radio telephone engaged in a call from being cut off when a power failure occurs, wherein the radio telephone is branched with a wire telephone by a telephone line. When the power is off while engaged in a call, the telephone line is held on by a state of a line voltage and a music on hold is generated. If power turns on again in a holding state, a power off cancel data is transmitted to a portable device. If a response data from the portable device is received, the holding state of the telephone line is canceled and the music on hold is stopped, and the call through the radio telephone is connected again. If the power is not on again or if the response data is not received, it is checked during a given time whether the wire telephone is hooked off or not. If the wire telephone is hooked off or if the given time has passed, the holding state of the telephone line is canceled and the music on hold is stopped.

Abstract: A method that can be used not only for elimination of noise, for example in automatic speech recognition, but also to improve the voice quality for people, for instance during use of the speaker function of a car phone. The noise reduction is executed with two or multiple channels in such a manner that the temporal and architectural acoustical signal properties of speech and interference are utilized step-by-step and systematically. According to the method a pivotable, acoustic directional lobe is produced for the individual voice channels by respective digital directional filters and a linear phase estimation to correct for a phase difference between the two channels. The noise in the individual voice channels is estimated during speaking pauses, and the temporally stationary noise sources are damped by means of spectral subtraction. The individual voice channels are subsequently added whereby the statistical disturbances of spectral subtraction are averaged.

Abstract: A video telephone to be connected to the ISDN is a unitary structure comprising a communication controller for controlling communication of digital data, such as voice signal, image signal and facsimile/camera control signal, a dial or key panel unit, a telephone controller for controlling the functions of a handset and the key panel unit, a camera for inputting an image, a display for outputting an image, and an image CODEC for coding an input image signal and decoding a received image signal. The camera is tiltable and detachable.

Abstract: A grille cloth for speaker assemblies is preformed into a desired shape and has sufficient rigidity to maintain this pre-formed shape while being supported in a non-tensional manner only at its periphery. The use of such a pre-formed fabric as a grille cloth eliminates a need for non-peripheral support while visually obscuring the components of the speaker assembly behind the grille cloth. The grille cloth is comprised of a polyester material which is substantially transparent to acoustic radiation in the audible frequency range while also being substantially opaque to visible light.

Abstract: A volume/balance control apparatus includes a plurality of resistance arrays which correspond to a plurality of channels, a volume operator and a balance operator which generate volume and balance signals according to user's operation, an operation signal synthesizing means for producing synthesized control signals pertinent to each channel by synthesizing the volume signal and balance signal, and a plurality of decoders for decoding the output from the operation signal synthesizing means and applying the result to a switching element included in each resistance array. The volume/balance control apparatus has only one resistance array per channel, thereby improving noise characteristics, and permits the independent operation of volume and balance controls, thereby enhancing user convenience.

Abstract: A high quality stereophonic sound enclosure system high resolution intended for computer visual display monitors employing cathode ray tubes (CRTs) having a vertical aperture grill, and methods for construction of same. The aperture grill has a natural frequency centered within the musical scale. The stereo speaker system comprises a ported speaker enclosure within which are mounted two conventional cone speaker assemblies. A stereo audio amplifier and control unit for controlling the audio signals delivered to the speakers is mounted within the speaker enclosure. The speaker enclosure is internally mounted within the monitor with a minimum number of attachment members incorporating vibration isolation material to remove vibration components near the natural frequency of the aperture grill. The speaker enclosure is internally reinforced to reduce structural deformations which contribute to airborne transmitted vibration within the monitor housing when the speaker system is operating.

Abstract: A cellular mobile communication system in which each of one or more cells is provided with a base radio station, and mobile terminals communicate with the base radio stations. Base radio stations (21, 22 and 23) are connected to a central base station (100) by optical fibers. The central base station is connected to a mobile switching center (50). Each of the base radio stations is provided with an O/E converter (201) and E/O converter (207). The O/E converter converts a optical signal containing speech signals and a call connection control signal into RF signals. The E/O converter (207) converts RF signals, received from a mobile terminal (11) via an antenna (204), into optical signals and transmits the optical signals to the central base station.

Abstract: A self-contained, hand-held device for testing an aircraft helmet communication system including a microphone and earphones in which a selection switch on the housing of the device is movable from an off position to a talk-through position at which the microphone is connected to both the earphones and a volume indicator on the housing and to a self-test position in which actuation of a pushbutton switch on the housing applies the output of an oscillator both to the volume indicator and a circuit having a voltage divider made up of a potentiometer and a fixed resistance to provide a self-test signal which energizes an illuminable element on the housing if the device is functioning properly and to an earphone impedance test position at which the output of the oscillator is applied to a circuit having a voltage divider made up of the potentiometer and the earphones to produce an earphone impedance-test signal which energizes the illuminable element if the earphone impedance is of the correct value.

Abstract: Coaxial loudspeaker arrangements (10) are usually so configured, that the loudspeaker (12) located in the bellmouth (29) of the conical loudspeaker (11), is placed on the pole core (17) of the conical loudspeaker (11). However, the contact of the loudspeaker (11) has a disadvantage, with respect to automated manufacture, because either the connection cables (24) for loudspeaker (12) must be threaded through the pole core (17), or the connection cables (24) must be connected to the soldering joints in the diaphragm (15). It is also known to place the loudspeaker (12) into a preform, and to attach this preform to the edge of the loudspeaker frame (14) of the conical loudspeaker (11). The latter is very costly and detrimental to the acoustical effect. For that reason the invention has the task of indicating a coaxial loudspeaker arrangement (10), which is simplified with respect to automated manufacture, without impairing the acoustical effect.

Abstract: An electroacoustic amplifier arrangement comprises a plurality of microphone arrangements each of which includes a microphone coupled to a comparator and coupled via a coupling circuit to a variable gain amplifier. The amplifier arrangement further includes a threshold signal generator. The threshold signal generator has a first and a second input coupled to the input and output, respectively, of the amplifier and is arranged to derive a threshold signal as a function of the signals applied to its two inputs. The output of the threshold signal generator is coupled to a second input of the comparator. The threshold signal generator is arranged to derive a threshold signal as a function of the gain factor adjusted in the amplifier.

Abstract: A shading correction circuit for correcting the shading distortion of a photoelectric conversion device including a plurality of arrayed photocells, has a memory for storing data on the output characteristics of each pixel, represented by image signals having a given level outputted by the photoelectric conversion device a plurality of image pickup times. Thereby, the data on the output characteristics of each pixel stored in the storing means is read by desirably switching the order of the image pickup for each pixel to provide shading correction data. Noise or irregularities which readily appear on the output picture after shading correction are reduced.

Abstract: A system is disclosed for supplying information in electronic form from a database to subscribers at a plurality of remote locations. Subject matter descriptors are applied to newly acquired information, and these descriptors are compared with information interest profiles maintained for all of the subscribers. Each subscriber also has an assigned identification number. A list of identification numbers is prepared as a result of the interest check, and this list of numbers is broadcast by radio transmission. The subscribers are equipped with radio receivers able to recognize their assigned numbers. When a radio receiver recognizes its identification number, it causes an associated remote computer to call the database and request transmission of the document by telephone link.

Abstract: A multiprocessor alarm data processing system includes a database with identifying information for all the central stations and their subscribers who use the system. Several input processors receive alarm data from the central stations to identify subscribers incurring alarm events. The input processors generate event records for alarm data validated against the database. Several output processors are provided to process the event records to select the appropriate municipal authority and transmit thereto identifying information for a sucscriber incurring an alarm event. The processors may be switched between input and output processing for dynamic internal load shifting and redundant processing systems are provided for inter-system load sharing. A busy-out capable modem is provided to facilitate such inter-system load sharing.

Abstract: A contactless charging system of a radio telephone comprising a portable device and a base unit, for charging a battery of the portable device, without electrical contact, by induction voltage of an electromagnetic field formed by the inductive coupling of a digital power receiver of the portable device and a digital power transmitter of the base unit, when the portable device is placed in the base unit.

Abstract: Apparatus and methods for providing cellular mobile telecommunication service in accordance with the requirements of the Global Systems for Mobile Communications (GSM) standard. A modular switching system is provided which performs the functions of the mobile switching center plus those of a home location register, authentication center, visitor location register, and equipment identity register. The latter functions are advantageously spread among the modules of the switching system, thus avoiding the getting started cost of expensive dedicated data bases. A wireless global switching module advantageously switches mobile communications control messages among the modules of the system and between the modules and the base station systems, and terminates signaling links between the mobile switching center and the base station systems.

Abstract: A cellular telephone system includes a packet-switched digital data communication subsystem overlaying a circuit-switched (e.g., voice) communication subsystem, with voice and data services sharing the same voice channels. The voice communication subsystem provides voice services independently of the operation of the data communication subsystem. On the other hand, the data communication subsystem monitors use of the voice channels for voice communication, and, in response thereto, temporarily allocates one or more of the available voice channels for data service. In a preferred embodiment, each data basestation transmits, from time to time, an available-channel signature to identify those, if any, of the data-allocated channels that are not then being used to transmit voice or data.

Abstract: A multimode service system processes calls routed to it by a digital switch in a telecommunications system wherein choices are selectable by the user. Calls are processed by automatically determining the mode of communication utilized by the calling party and communicating with the calling party utilizing the calling party's communication mode to obtain information needed to route the call or implement user selectable features. A reply from the user provides information which determines feature selection or a call routing path. The multimode service system transmits a signal to the telecommunications system which defines the feature or path selection based on the reply from the user.

Abstract: A signal processing circuit for an audio apparatus has a variable gain amplifier whose gain is varied in accordance with a gain controlling signal supplied thereto. The signal processing circuit comprises a gain setting section having a plurality of tables of input-output characteristics according to a level of loudness selected by a user. The characteristics being for the variable gain amplifier. A table selecting section selects a corresponding one of the plurality of input-output characteristics in accordance with the selected level of loudness. The table selecting section supplies the corresponding input-output characteristic to the variable gain amplifier so as to set the variable gain amplifier for a gain corresponding to the input-output characteristic.

Abstract: A method and apparatus for reliably delivering messages (200) from a central terminal (102) to a communication receiver (130) in a communication system (100), such as an electronic mail system. The central terminal (102) transmits messages (1300) to the communication receiver (130) and the communication receiver (130) receives transmitted messages (1300) over a first communication medium (122). The communication receiver (130) reconciles messages that it failed to receive over the first communication medium (122) with the central terminal (102) over a second communication medium (152). The reconciliation process between the communication receiver (130) and the central terminal (102) utilizes cyclic redundancy codes (CRCs) transmitted with the messages (1300) to identify the messages (1300) being reconciled.