Abstract: A modem having reduced power dissipation and temperature compensation. The modem includes a data pump, a telephone line interface, memory and a controller, connected to the memory and the data pump, for executing program code to control transfers between the data pump and a telephone line. The telephone line interface includes a current-limited loop holding circuit in order to limit power dissipated in the modem due to DC loop current. The current-limited loop holding circuit includes a constant current source in series with a DC loop holding circuit.

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.RTM. 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.

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.RTM. 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.

Abstract: A data multiplexing network is described which multiplexes a plurality of asynchronous data channels with an asynchronous data stream representing compressed voice signals and/or facsimile signals onto a single synchronous data packet stream. The single synchronous data packet stream is then transmitted by a high speed statistical multiplexer over a composite link to a second site using a modified high-level synchronous data link control protocol with an overlay of an advanced priority statistical multiplexing algorithm. The asynchronous data channels and the compressed voice channel and/or facsimile signals are demultiplexed and reconstructed for sending to other asynchronous computer terminals and to a standard telephone or facsimile analog port at the second site, respectively. PBX trunk interfaces are also provided to allow PBXs to share the composite link between sites. Communication between the first site by voice or facsimile and the second site is transparent to the users.

Abstract: The voice over data component of a personal communications system enables the operator to simultaneously transmit voice and data communication to a remote site. This voice over data function directly encodes digitized voice samples onto the carrier using quadrature amplitude modulation to transmit multiple bits of the voice sample for every baud. The system also allocates selected bauds of the carrier to voice and to data so the voice over data may be transmitted using the same allocated bandwidth. The system may also dynamically reallocate the bandwidth over the telephone line depending on the demands of the voice grade digitized signal.

Abstract: An intelligent LAN modem node is used in a bridge system which provides transparent internetwork communications over a plurality of channels. The LAN modem node is protocol independent and has a packet load distribution system which shares packet traffic across the channels using optional user-defined channel preferences. The LAN modem nodes used in the bridge system provides compression for increasing bridge transmission speed. The bridge system provides a filtering system to control access over the bridge and restrict unnecessary bridge traffic. Additionally, the bridge system provides automatic redial in the event modem communications are lost.

Abstract: A data multiplexing network is described which multiplexes a plurality of asynchronous data channels with an asynchronous data stream representing compressed voice signals and/or facsimile signals onto a single synchronous data packet stream. The single synchronous data packet stream is then transmitted by a high speed statistical multiplexer over a composite link to a second site using a modified high-level synchronous data link control protocol with an overlay of a priority statistical multiplexing algorithm. The asynchronous data channels and the compressed voice channel and/or facsimile signals are demultiplexed and reconstructed for sending to other asynchronous computer terminals and to a standard telephone or facsimile analog port at the second site, respectively. PBX trunk interfaces are also provided to allow PBX's to share the composite link between sites.

Abstract: A method for the high-speed transfer of data between an IBM compatible personal computer (PC) and a bus device. A DMA controller is placed on the bus device to by-pass the PC's DMA controller. High-level terminate and stay resident software on the PC uses a combination of the DMA controller on the bus device and low level DMA controller routines to transfer the data between the PC and the bus device.

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.RTM. 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.

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.RTM. 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.

Abstract: Updated operating code and parameters can be reprogrammed into a modem system with no disassembly of the modem hardware. The modem system includes an in-circuit reprogrammable memory chip in which operating code and parameters are stored. Two control programs control the reprogramming of updated operating code. One of the control programs is designed for manufacturing and testing purposes. The other control program allows remote reprogramming of updated operating code or parameters from a remote location such as a customer site. The modem system is portable, obtaining power from a standard 9 volt battery. Therefor, various power saving features are also incorporated into the modem system.

Abstract: The present invention provides for a virtual modem device for connecting to a plurality of active communication applications in an environment wherein communication applications utilize a communications driver when talking to an actual modem attached to the system. The virtual modem device selectively connects the communication applications to an actual modem, handles and connects incoming calls to the appropriate communication application, and provides for direct connection capability. The invention utilizes a software communications driver and a master communications application to control the driver connectivity to fool each communication application that it is connected to the actual modem. The virtual modem is implemented by creating a communications driver in software that emulates a modem in idle mode (e.g., when it is not off-hook and in command mode)and is utilized for each communication application that is connected to a communication port designated as a virtual modem.

Abstract: A personal communications system enables the operator to simultaneously transmit voice and data communication to a remote site. The personal communications system is equipped with two telephone line interfaces to allow connection between two remote sites. The connection between the first remote site and the local site may operate in a voice over data communications mode to simultaneously send compressed voice and data. The connection between the local site and a second site is a voice only connection allowing the first remote site to talk to the second remote site without breaking the data communication connection between the first site and the local site. The second remote site amy be a public telephone network. The communication between the first remote site and the second remote site through the local site may also be a data communication connection, or it may also be a voice over data communication connection.

Abstract: A personal communications system enables the operator to simultaneously transmit voice and data communication to a remote site. The personal communications system is equipped with two telephone line interfaces to allow connection between two remote sites. The connection between the first remote site and the local site may operate in a voice over data communications mode to simultaneously send compressed voice and data. A digital transmission protocol which is consistent with current packet standards is used to create an independent channel through use of a modified supervisory packet for negotiating communication parameters, including the speech compression algorithm, the speech compression ratio, the communication multiplex scheme, and other operations needed for control of remote hardware interfaces.

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.RTM. 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.

Abstract: A system for performing voice compression which includes, a conversion means for converting analog voice signals into discrete samples of digital voice data and collecting the discrete samples into segments, with a means for dividing the segments into subsegments and for producing therefrom a current voice subsegment. A pitch prediction means is used for determining the long term predicted gain of the current voice subsegment by comparing the current voice subsegment to reconstructed voice samples to produce a pitch predictor gain and a lag component and a pitch filter means is used for pitch filtering the current voice subsegment based on the pitch predictor gain and the lag component which then produces long term residual samples.

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.RTM. 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.

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.RTM. 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.