Showing papers on "Telephony published in 1993"

Computer-based multifunction personal communications system.

Abstract: A personal communications system is described which includes components of software and hardware operating in conjunction with a personal computer. The user interface control software operates on a personal computer, preferably within the Microsoft Windows® environment. The software control system communicates with hardware components linked to the software through the personal computer serial communications port. The hardware components include telephone communication equipment, digital signal processors, and hardware to enable voice, fax and data communication with a remote site connected through a standard telephone line. The functions of the hardware components are controlled by control software operating within the hardware component and from the software components operating within the personal computer. The major functions of the system are a telephone function, a voice mail function, a fax manager function, a multi-media mail function, a show and tell function, a terminal function and an address book function. The telephone function allows the present system to operate, from the users perspective, as a conventional telephone using either hands-free, headset or handset operation. The telephone function is more sophisticated than a standard telephone in that the present system converts the voice into a digital signal which can be processed with echo cancellation, compressed, stored as digital data for later retrieval and transmitted as digital voice data concurrent with the transfer of digital information data.

Mobile communication network with remote updating of subscriber identity modules in mobile terminals

Abstract: A communications network has a switching network including a mobile switching centre (MSC 10) which communicates, e.g. by radio telephony, with mobile equipment (ME 12), such as a mobile telephone. The mobile equipment contains a subscriber identity module (SIM 20) which stores data for controlling the operation of, and the facilities available to the user, of the mobile equipment (12). In accordance with the present invention, the switching network transmits updating signals to the mobile equipment (12) which alter the data stored in the subscriber identity module (20), and hence alter the operation on facilities available.

Method and apparatus for delivering passband and telephony signals in a coaxial cable network

Abstract: A method and apparatus for delivering passband and telephony signals including signal combining and splitting. The method and device employs passive electronics in the form of L-filters, high pass filters and low pass filters to deliver baseband telephone communications and interactive video communications.

Cellular hand held portable speakerphone system having an interface adapter

Abstract: A hand held cellular telephone system including voice storage features which enable the cellular telephone to perform functions similar to a telephone answering device, a battery monitoring system for providing the user with a real time display of the amount of time remaining for use of the cellular telephone in both the standby and conversation modes, and an interface adapter which may be used to provide speakerphone functions, power the cellular telephone, and recharge the battery.

Video telephony dialing

Abstract: In a video telephony system, a coaxial cable network, which is preferably a part of an existing cable television system, provides a local link for the transmission of the video telephone signals between each originating and destination location and a respective "head end" located on the cable company premises. Each of the head ends is connected to a "point of presence" of a telephone interexchange carrier so that a connection between pairs of head ends, and thus between a pair of video telephone locations, can be made via a switched digital network maintained by the carrier. Certain of originating and destination locations comprise a standard television set, serving as the audio/video display, and a consumer-type camera or camcorder, serving as the audio/video source. Others of the originating and destination locations comprise ISDN video telephones which are connected to the various points of presence of the interexchange carrier via local exchange carrier telephone networks. The video telephone numbers for cable subscriber locations are administered to be the same as the standard ten- (i.e., area code plus seven-) digit telephone numbers used for regular telephone calls directed to those locations.

Apparatus and method for transparent telephony utilizing speech-based signaling for initiating and handling calls

Abstract: A transparent telephony system is disclosed for providing hands-free communication. The transparent telephony system includes a device for initiating a call between a caller's location and a call destination based on a voice utterance (e.g., the call recipient's name) made by the caller, a device for reproducing the voice utterance made by the caller at the call destination so that the call recipient may identify the caller, and a device for handling the call attempt in accordance with a voice utterance made by the call recipient. The call handling device enables the call recipient to optionally accept the initiated call and establish two-way voice communication with the caller by uttering an appropriate voice command ( e.g., "go-ahead" or "yes"). Further, the system provides telecommunications between parties that seems "transparent" with respect to the actual communication network involved, partly since the caller's voice command initiating the call and the call recipient's acceptance utterance are forwarded and heard by the respective parties as if they are initiating a normal conversation with one another in the same room or location.

Adaptive array noise suppression of handsfree speaker input in cars

Abstract: Handsfree speaker input of mobile telephones is most desirable today in order to enable safe operation in cars. This is also a prerequisite for voice control of car devices. This paper presents an "on the road" evaluation of the performance of an adaptive microphone array for speech enhancement in cars. The results show a signal-to-noise ratio (SNR) improvement in the range of 10-15 dB over the telephone frequency range with a slight favour for higher frequencies when driving at normal speeds. >

Bidirectional video telephony between cable television and switched telephone systems

Abstract: In a video telephony system, a coaxial cable network (121, 126), which is preferably a part of an existing cable television system (121, 126, 122, 127), provides a local link for the transmission of the video telephone signals between each originating and destination location (101, 105) and a respective "head end"(122, 127) located on the cable company premises. Each of the head ends is connected to a "point of presence" (161, 162) of a telephone interexchange carrier so that a connection between pairs of head ends, and thus between a pair of video telephone locations, can be made via a switched digital network (160) maintained by the carrier. Certain of originating and destination locations comprise a standard television set (103, 106), serving as the audio/video display, and a consumer-type camera or camcorder, serving as the audio/video source. Others of the originating and destination locations comprise ISDN video telephones (111, 115) which are connected to the various points of presence of the interexchange carrier via local exchange carrier telephone networks (140, 145). The video telephone numbers for cable subscriber locations are administered to be the same as the standard ten- (i.e., area code plus seven-) digit telephone number used for regular telephone calls directed to those locations.

Communications system, switching exchange and line card

Abstract: A cordless telephony system includes a switching exchange having a conventional switch which may be coupled to the public network. To avoid loading of such switch, the exchange also includes a backbone coupling network coupled to cluster controllers for respective clusters of base stations. Such network transports data between the cluster controllers during handover of a roaming mobile telephone set between different base stations. The system may be used as a private branch exchange operating with a central controller. The cluster controllers may be in the form of line cards which communicate with each other via the backbone coupling network, control being effected in a decentralized mode.

Toward Competition in Local Telephony

Abstract: Actual and prospective competition in local telephony regulating local telecommuncation - some basic principles regulating the pricing of final products - preliminary concepts price floors for final products price ceilings for final products the pricing of inputs sold to competitors policies to promote entry conclusion - toward a revised regulatory system.

System and method for providing selected video images to local telephone stations

Abstract: A system and method for providing subscriber selected advertising in the form of video images to a local telephone station is disclosed. The telephone network includes a telephone line system and switch facility contained within the line system for forwarding calls made by a calling party from a local telephone station through the telephone line system to a destination point. The local telephone station is interfaced with the network. The phone includes a display monitor for receiving data corresponding to video images and displaying same. The images are stored in a central database and compressed into data packets of lesser bandwidth for transmission from the database through a network interface and into the existing telephone line system packet form to the local telephone station where they are arranged and decompressed for display on the monitor. A plurality of telephone stations can be grouped into a cluster unit. In this format, video data is preferably compressed, multiplexed, transmitted over the telephone network, demultiplexed and then decompressed for display at respective monitors.

Facsimile store and forward system with local interface translating DTMF signals into store and forward system commands

Abstract: A local router interface couples a conventional facsimile device to the public switched telephone network (PSTN) to communicate with a remotely located facsimile store and forward facility (F-SAFF) to perform a host of improved facsimile service methods, including a never no answer or busy send (NNABS) method, a never no answer receive (NNAR) method, a private facsimile method, a will call facsimile method, a pager facsimile method, a facsimile mail method, a facsimile information retrieve method, a facsimile information send method, a facsimile cover method, a facsimile speed cover method, a facsimile broadcast method, a facsimile flexible broadcast method, a facsimile access restriction method, a facsimile conversion method, an urgent facsimile method, and a facsimile addition method. Innocuous call progress monitoring with fast busy detection, post-fax line holding, F-SAFF-to-remote and remote-to-F-SAFF bridging are provided. The router includes detectors for loop-current, ring signals, call progress signals, precise busy signals, dual tone multi-frequency (DTMF) signals, and modulated data signals, as well as generators for going off-hook, generating and transmitting DTMF signals and modulated data signals over a wall phone line as well as ring and dial tone signals through an adjustable amplifier circuit and a subscriber line interface circuit to a fax telephone line. A switching connection circuit is also included for selectively connecting the wall phone line to the fax phone line and for selectively connecting other components of the telephony interface thereto.

Dual-line telephone bridging device that gives remote telephones access to communications features

Abstract: A feature telephone having an internal mechanism for providing access to its features from a remote location. Without third party intervention or the aid of special features on a PBX or public network, a remote user can set up his office phone to transfer telephony features to another phone, such as his home phone. For example, a user can gain access to his company's tie lines and private network from his home telephone. A user can also bill data calls to his office phone or receive office calls at his home phone without the use of a PBX or public network call forwarding feature. According to another aspect of the mechanism, a user can also set up a password to restrict access to his telephone's features and set up a time of day clock to activate call forwarding and feature access between predetermined hours of the day.

Automatic cellular telephone control system

Abstract: Embodiments of an invention for quantitative testing of a radio telephony network are disclosed. An embodiment includes a computer that causes various transceivers to place calls on the network. The computer receives or determines operational parameters of the transceivers or transmission quality associated with those calls and stores the operational parameters for later data processing. Systems for displaying the stored operational parameters on a map are also disclosed.

The Qualcomm CDMA digital cellular system

Abstract: Qualcomm, Inc. has developed and tested a digital spread spectrum cellular telephone system that will supplant and evetually replace the existing analog FM cellular system. TIA has recently standardized this "CDMA" (Code Division Multiple Access) as TIA IS-95, and several cellular carriers have already announced plans to deploy the services. The original impetus for CDMA;s development was the enormous popularity of existing narrow band analog FM cellular telephone systems. There is only so much radio spectrum available to deal with the flourishing demand for cellular service, and severe congestion already exists in several major service areas. A IS-95 system can carry about 10-15 times as many voice calls as an analog system in the same spectrum. Although Qualcomm specifically designed IS-95 for voice telephony, it is easily adapted to packet data transmission. It can provide a service comparable to those of several existing and proposed metropolitan area wireless data networks with better performance, greater reliability, and lower cost.

Application of large vocabulary continuous speech recognition to topic and speaker identification using telephone speech

Abstract: The authors describe a novel approach to the problems of topic and speaker identification that makes use of large-vocabulary continuous speech recognition. A theoretical framework for dealing with these problems in a symmetric way is provided. Some empirical results on topic and speaker identification that have been obtained on the extensive Switchboard corpus of telephone conversations are presented. >

Method and apparatus for emulating telephonic communications with a modem and headset

Abstract: An emulator circuit is provided for allowing a data/fax/voice modem, a host computer, and a telephone headset to emulate the functions of a telephone. For voice communications, the emulator circuit connects the telephone headset to a communication device such as a telephone line or cellular radio. For automated data/fax/voice communications, the emulator circuit connects the modem to the communication device. Two specific embodiments of the emulator circuit are described. In one, the emulator circuit is configured from analog circuit components connected to the modem. In the other, the emulator circuit is an integrated circuit component of the modem. In both embodiments, the provision of the emulator circuit obviates the need to provide a separate telephone for handling voice telephone conversations and other communications through said telephone line, cellular radio. An embodiment is also described wherein an emulator circuit is connected to either a telephone line or a cellular radio or other communication device. A switch is provided for selecting between the telephone line and the cellular radio.

Option bus adapter

Abstract: A method and apparatus for connecting a programmable computing device to a digital telephone via an adapter. The digital telephone includes an option bay connection, having a hierarchical control protocol. The option bay connection makes available several types of information including local analog audio, and analog voice, digital voice, digital data and telephone control streams. The adapter passes the telephony control data to and from a programmable computing device such as a personal computer, enabling an application operating on the computing device to control or monitor the operation of the telephone. The adapter includes a microcontroller and an interface for a serial port and can thus be connected to the serial port of the programmable computing device.

Telephone line sharing for a personal computer system

Abstract: A method and apparatus for processing an incoming call over a telephone line in a computer system, wherein a telephone manager program passes the telephone line to a telephony application program according to at least one user option, a set of user preferences, and DTMF or calling tones.

Qcelp: The North American Cdma Digital Cellular Variable Rate Speech Coding Standard

Abstract: Digital cellular telephone systems require efficient encoding of speech to achieve capacity improvements required of the next generation of cellular systems. The use of a variable rate speech coder can reduce the average data rate required to transmit conversational speech by a factor of two or more, while providing many other advantages. This reduction in average data rate leads to a factor of two increase in the capacity of a Code Division Multiple Access, or CDMA, based digital cellular telephone system by decreasing the mutual interference among users. This chapter describes the “QCELP” algorithm, which has recently been selected as the North American CDMA digital cellular variable rate speech coding standard [l, 21.

The Provision of Telephony over Passive Optical Networks

Abstract: The application of optical technology to the local network has been a field of increasing interest and debate over the past few years [ 1 ]. While it is usually assumed that optical networks will penetrate to small businesses and residential customers to provide an integrated range of services, it is recognized that the economics of both the technology and the revenue from new services are uncertain.

Transmission power level adjustment in radio telephony

Abstract: A mobile telephone system multiplexes plural voice traffic channels on a single carrier using a TDMA protocol The capacity of the mobile telephone system is increased by assigning voice traffic capacity, not on a conversation basis, but on a speech spurt basis Accordingly, delays of undetermined duration may occur between subsequent information bursts which correspond to the transmission of speech spurts An adjustment request regarding the power with which the information bursts are transmitted from a transmitting station to a receiving station is generated by detecting an information burst transmission at the receiving station, measuring the time which elapses following the transmission, and comparing the elapsed time with a predetermined threshold value If the elapsed time exceeds the threshold, a further transmission is requested from the transmitting station notwithstanding the availability of any information to transmit The power of the transmission received in response to the request is measured and a control message for requesting an adjustment to the transmission power level in response to the measurement is transmitted to the transmitting station

Telephone network performance monitoring method and system

Abstract: The present invention automatically initiates a telephone call to a given destination (4). At the same time, the progress of the call is monitored. The time of a ring back and voice answer received from the destination (4) are recorded to an output file. At the end of the voice answer, a pre-recorded voice message is sent by the system (2) to the person answering at the destination (4). Thereafter, the recorded data is used to determine the response time for that particular telephone destination. A plurality of destinations can be tested. A second embodiment of the present invention provides for the interactive correspondence between a remote evaluation unit and a called destination and the measurement of the performance characteristics of the telephone network.

Voice server for digital communication network

Abstract: An interface for coupling a standard telephone set to a distributed digital network for allowing digital voice communication over the distributed network such that the utilization of the distributed network is wholly transparent to the user. An interface is provided for each telephone set. Each interface includes a state machine, a coder/decoder and a digital tone generator. The state machine is responsive to analog control signals from the telephone set to generate digital control signals to be transmitted over the distributed network. The state machine is also responsive to digital control signals to control the digital waveform generator to generate supervisory tones which are relayed to the user by the telephone set. The state machine also monitors the operation of the corresponding state machine or machines in a normal or conference call and sends control signals to resolve inconsistent states of the respective state machines, resulting in a high degree of fault tolerance and independence from network protocols.

Telecommunications network having switching centers for linking satellites

Abstract: A telecommunications network comprises a constellation of orbiting satellites placed in low-altitude polar inclined orbits with two inter-satellite links per satellite, a network of earth-based centers enabling the management and the control of the local traffic and one or more high latitude centers to set up the interconnections between satellites that are not in one and the same orbit. Application to telephony by mobile and/or fixed terminals.

Digital switching system connecting buses with incompatible protocols and telephone answering system and private automatic branch exchange with integrated voice and textual message recording

Abstract: A digital switching system connecting buses with incompatible protocols and a telephone answering system and private automatic branch exchange with integrated voice and textual message recording is disclosed. The digital switching system (10) in accordance with the invention permits a digital switching matrix (12) having an input bus and an output bus to connect information on the input bus selectively to information on the output bus in response to control signals applied to switches of the switching matrix. A plurality of information systems (18, 20 and 22) each having a different bus protocol are electrically connected to the input and output buses of the switching matrix to permit information transmitted on a conductor of any of the information buses to be received by another conductor of any of the information buses through the input bus, the switching matrix and the output bus. A host processor controls the plurality of information systems. Furthermore, the host processor may be used to commonly control textual message and voice message recording systems within a telephone answering system and commonly control telephony functions and textual message and voice recording systems within a PABX.

Radio telephony system using a multisubscriber unit

Abstract: A digital cellular communication system (18) where fixed subscribers and mobile subscribers can share base transceiver stations (28), base station controllers (29) and mobile switching centers (30) to communicate with a PSTN (32). Mobile (20) and fixed (26) subscribers can communicate via any common cellular radio protocol, but the fixed subscribers communicate through conventional telephones using a multisubscriber unit (22). The system (18) preferably uses a digital speech interpolation pool in a time division multiple access system having different carrier frequencies each of which are time divided into six time slots. The multisubscriber unit communicates with the base transceiver station over a radio link managing most of the tasks required for the air interface so that inexpensive conventional telephones can be used for the fixed subscribers.

Teleconferencing for cost-effective sharing of radiology educational resources: potential and technical development.

Abstract: To develop a cost-effective method of sharing educational resources, a dial-up teleconferencing network was implemented between three radiologic sites for a 30-day period of evaluation. By means of standard dial-up telephone channels, compressed video and audio signals displayed radiologic images, slides, and text, allowing residents and faculty from the three sites to participate in sight and sound interactions. Each of the three sites used compressed video/audio coder-decoders (codecs) conforming to the Consultative Committee on International Telegraphy and Telephony H.261 standard. Four video cameras were used at each site, and the audio was run in full duplex mode. A multipoint video bridge was used to broadcast codec output signals to the input lines of the other codecs. Our evaluation found audio quality to be suboptimal, but capable of being improved; diagnostic image quality was adequate when a video zoom mode was used; the digital-archive mode of the codec proved advantageous; the H.261 codec per...