Abstract: A noise calculation mechanism is incorporated into a cadence tone detector which upon a miss in either a energy or silence interval allows for retention of those periods corresponding to noise and augments the appropriate energy and silence interval.

Abstract: A method for remotely communicating with a Broadband modem is provided. Once a communication error is detected on a Broadband modem, a Plain Old Telephone System (POTS) connection is established between the Broadband modem and a remote server. Communication then occurs with the remote server via the POTS connection using Dual-Tone Multi-Frequency (DTMF) tones. The communication preferably comprises transmitting information associated with the communication error to the remote server via the POTS connection using DTMF tones and receiving a diagnosis from the remote server via the POTS connection in DTMF tones. A system for remotely diagnosing a Broadband modem as well as a Broadband modem is also provided.

Abstract: A method and apparatus are provided for processing signals received on a R2 multifrequency compelled signalling subscriber channel within a telephone switch. The method includes the steps of disposing a digital signal processor within the telephone switch between an inbound path of the R2 multifrequency compelled signal subscriber channel and a controlling processor of the telephone switch and detecting an R2 multifrequency compelled signalling control transmission by the digital signal processor on the inbound path. The method further includes the steps of responding to the control transmission by the digital signal processor transmitting an acknowledgement on an outbound path of the subscriber channel and transferring a symbolic representation of the control transmission to the controlling processor of the switch.

Abstract: The present invention relates to a demodulator which receives a signal transmitted via phase modulation or multivalue QAM modulation, and decides transmitted data based on the received signal. The present invention enhances a transmission-line estimate by using tentatively decided data symbols as pilot symbols and in estimating a transmission line without a decrease in accuracy of transmission-line estimate even when an error rate of the tentatively decided data symbols is increased. The demodulator includes a pilot-based transmission-line estimation unit for estimating transmission-line characteristics by using pilot symbols. A tentative-data-decision unit for tentatively deciding data symbols based on the pilot-based transmission-line estimate. A data-based transmission-line estimation unit for estimating the transmission-line characteristics by using the tentatively decided data.

Abstract: A high-speed wireless transmission system is employable in a macro-cellular environment. In the system multiple transmit antennas are employed. Multiple carrier tones are used to transmit the data. The carrier tones can be assigned to the respective transmit antennas in such a manner as to provide each antenna with a subset of carrier tones with each subset being spread over the transmission spectrum. In addition, operation is enhanced by providing Reed-Solomon coding of the data across consecutive time intervals.

Abstract: A method and system for accessing a remote system via a computer connected to a packet data network, comprises a Packet Data Network Gateway (PDNG) is connected to the packet data network. The PDNG receives a signal representing a DTMF tone transmitted from the computer, generates the DTMF tone at corresponding to the received signal, and transmits the generated DTMF tone to the remote system. The PDNG receives a response from the remote system and creates at least one voice packet for transmission to the computer over the packet data network. The remote system may be a voice messaging system or an interactive voice response (IVR) system.

Abstract: A musical tone data communications system having a unit for generating MIDI data of a musical performance by a player, a unit for transmitting the generated MIDI data over a communications network and a unit for receiving the transmitted MIDI data and reproducing musical tones corresponding to the MIDI data in real time.

Abstract: A method of transmitting DTMF signals over a compressed computer network (24) comprises sending a packet containing a compressed DTMF signal followed by a confirmation packet. The confirmation packet preferably comprises an uncompressed DTMF signal which is transmitted on the same logical channel as the packets that represent voice signals. To detect the DTMF signal transmitted, a telephony Internet server (28) decompresses packets as they are received. If a packet appears to contain a compressed DTMF signal, the telephony Internet server looks for the presence of the confirmation packet before processing the previously received packet as a DTMF signal. In an alternative embodiment, the confirmation packet comprises a code that represents a DTMF signal. The packets that represent the voice signal and the code representing the DTMF signal are sent on separate virtual channels of the same logical channel.

Abstract: A DTMF transmission structure of a W-CDMA WLL system in which a DTMF signal is transmitted and received to and from a switching system through a terminal station and a base station controller, each of the terminal station and the base station controller comprising: an echo canceller for extracting an echo component from a received signal; a DTMF detector for discriminating whether a signal to be transmitted is a DTMF signal and controlling the operation of the echo canceller; an adder for adding the signal to be transmitted and the output of the echo canceller; a VOCODER for coding the output signal of the adder to a bit stream form or decoding the received signal in the bit stream form to an analog signal; an adjusted DTMF detector for detecting a digit component from the output of the VOCODER; a DTMF generator for reproducing a normal DTMF signal according to the detected digit component; and a silence generator for generating a silence for a predetermined time immediately after the DTMF signal is reproduce

Abstract: A subscriber unit of a time division multiple access (TDMA) radiotelephone system is, from a power consumption standpoint, reconfigured in each time slot of a TDMA frame to a power consumption tessellation in which subscriber unit circuit components not needed for communication signal processing in that time slot are powered down, and other components are powered up. Some circuit components are powered down by switching their power supply circuits. In order to minimize the extent of circuitry that must be provided to distribute power consumption control signals, other techniques (which utilize circuitry provided for other purposes), such as clock frequency control or power down commands, also are utilized to modify controlled circuit component power consumption without actually controlling power supply circuits.

Abstract: An ATM cell converting apparatus and method provided with a tone and DTMF generating function generates tone and DTMF which are necessary to a switching system and outputs to a TDM network channel data of an ATM cell type which are read from a cell buffer of a memory unit or tone and DTMF which are read from a tone and DTMF register in accordance with a function type of a data converting unit.

Abstract: A high-speed wireless transmission system is employable in a macro-cellular environment. In the system multiple transmit antennas are employed. Multiple carrier tones are used to transmit the data. The carrier tones can be assigned to the respective transmit antennas in such a manner as to provide each antenna with a subset of carrier tones with each subset being spread over the transmission spectrum. In addition, operation is enhanced by providing Reed-Solomon coding of the data across consecutive time intervals.

Abstract: A tone generating circuit comprises a counter circuit having a clock input for receiving a clock signal and a plurality of outputs which generate sequential binary values in response to transitioning of the clock signal; a multiplexer having several inputs, a number of select lines connected to the counter circuit outputs, and at least one output; and a resistor divider network connected to the multiplexer inputs. The multiplexer select lines select one of the multiplexer inputs in accordance with the binary value received from the counter circuit. The multiplexer inputs are connected to different taps on the resistor divider network. The counter selects multiplexer inputs on the falling edge of the clock signal, while the output signal level transitions before the rising edge of the clock signal.

Abstract: A method for multiple users accessing a common channel in which coded application bits are generated and transmitted for a plurality of applications for a plurality of users. A plurality of tones are assigned to the coded application bits for each application. The coded application bits for each application are encoded into multitone symbols at a transmitter using the plurality of tones assigned to the coded application bits. The multitone symbols for each application are synchronized for transmission on a common uplink channel. At a receiver, the multitone symbols for each application are received from the common channel and tone decoded into the coded application bits for each application using the plurality of tones assigned to the coded application bits. The coded application bits are then decoded for each application.

Abstract: An apparatus and method for facilitating interaction during a communication session between an analog modem and a terminal adapter for conveying digital alert tones and control data therebetween is provided. The embodiments provide for a collateral digital communication path between a microcontroller of an analog modem and a microcontroller of a terminal adapter for selectively relaying digital alert tones and control data therebetween. One embodiment utilizes a cellular interface of an analog modem for tapping and evaluating information for the presence of control data. Upon successful identification of control data, the microcontroller of a terminal adapter is notified and the specific control data detected in identified. By providing a method of apparatus for digitally relaying control data, accuracy of identification of control data by a terminal adapter is enhanced by foregoing needless signal transformation and retransformation.

Abstract: Methods and mechanisms for reducing the impact of radio frequency interference in multi-carrier data transmission systems are disclosed. In one aspect of the invention, dummy tones are used to suppress emissions within restricted frequency bands. In another aspect of the invention, signals received on designated quiet tones are detected and used to facilitate canceling of RF interference on adjacent active tones.

Abstract: A transmultiplexer is connected between digital facilities and analog facilities for translating information between TDM and FDM formats on the digital and analog facilities, respectively. Information in the TDM format is representative of a plurality of digital telephone signal channels and information in the FDM format is representative of a plurality of analog telephone signal channels. The total capacity of the digital facilities is smaller than the total capacity of the analog facilities. Any one of the digital channels can be selectively coupled to any one of the analog channels. The transmultiplexer is installed at a telephone central office facility as an interface between a cable telephony transmission system and a digital telephone switch. A host computer controls both the transmultiplexer and the digital telephone switch.

Abstract: A high-speed wireless transmission system is employable in a macro-cellular environment. In the system multiple transmit antennas are employed. Multiple carrier tones are used to transmit the data. The carrier tones can be assigned to the respective transmit antennas in such a manner as to provide each antenna with a subset of carrier tones with each subset being spread over the transmission spectrum. In addition, operation is enhanced by providing Reed-Solomon coding of the data across consecutive time intervals.

Abstract: A tone generator includes a controller for generating a frequency control signal, an address control signal, a tone period control signal and an automatic tone period mode, a sinusoidal wave generator having a nonvolatile table of a sampled value of .pi.

Abstract: An arrangement which utilizes the system memory to store the wave tables used in the generation of high quality sound, and a direct memory access controller to rapidly transfer the portions of the wave tables stored in memory using the system bus so that a sound card may manipulate high quality sounds from wave tables stored directly in system memory without overloading the system bus and without the need for substantial additional memory on the sound card.

Abstract: Improved telecommunication apparatus is realized with a structure that is tailored to interact with the telecommunication network strictly in packet format. The apparatus includes circuitry for creating either control or information packets, where each packet comprises a header portion and a payload portion. The apparatus also includes an identifier module that enables the apparatus to identify itself to the telecommunication network with an identifier signal that is unique to it. The apparatus further includes encoding and decoding circuitry to create, and decode, highly compressed digital representations of audio signals and, optionally, encryption and decryption features to enhance security of communication. Still further, the apparatus includes circuitry to enable users to interact with the network and partake of telephony service.

Abstract: A method and apparatus for transmitting digital sound is disclosed. The method contemplates transmitting a digital radio signal (such as an FM band signal) over a plurality of sub-channels subject to some constraints on the digital signal power. A control sub-channel, sometimes referred to as an auxiliary overhead channel is used to transmit control information which is interpreted by the receiver to identify the location and potentially the mode of the digital signals.

Abstract: A handshake between sending and receiving devices (10) that exchange DTMF signals across a network (14) is accomplished by having the receiving device send a DTMF ready tone (digit) for a prescribed interval following receipt of a call set-up message received after the sending device has initiated a call. Upon receipt of the DTMF ready digit, the sending device sends to the receiving device a data message includes a string of digits of interest prefixed by M header digits. After receiving at least a portion of the data message, the receiving device stops transmitting the ready digit. Once the receiving device has received the entire data message, the receiving device strips the protocol digits (the M header digits and any of the ready digits received due to echo). By analyzing the stripped protocol digits, the quality of the handshake between the receiving and sending devices can be determined.

Abstract: A tone generating circuit comprises a counter circuit having a clock input for receiving a clock signal and a plurality of outputs which generate sequential binary values in response to transitioning of the clock signal; a multiplexer having several inputs, a number of select lines connected to the counter circuit outputs, and at least one output; and a resistor divider network connected to the multiplexer inputs. The multiplexer select lines select one of the multiplexer inputs in accordance with the binary value received from the counter circuit. The multiplexer inputs are connected to different taps on the resistor divider network. The counter selects multiplexer inputs on the falling edge of the clock signal, while the output signal level transitions before the rising edge of the clock signal.

Abstract: A tone blocking system and method for use preferably in conferencing systems in order to prevent control tones from being transmitted to other conferees is disclosed. The buffer length used to process the signal and detect tones is varied, being increased when a tone is suspected to allow for sophisticated tone detection algorithms, and being decreased when silence is present by trimming the silence away. The technique minimizes delay, and its degrading effect on echo, but nonetheless provides for a lengthy buffer required to do reliable tone detection. The invention is applicable to any signal other than tone as well.

Abstract: An announcement apparatus for a switching system, comprising a host processor for controlling the output of announcement voices with respect to the total voice service channels, a DPRAM for storing voice output address data therein, a CPU responsive to an interrupt signal, for storing the voice output address data into the DPRAM and outputting voice output state data, a common memory for transferring voice output command data from the host processor to the CPU and transferring the voice output state data from the CPU to the host processor, a fixed voice memory for storing fixed announcement voice data therein, an edited voice memory for storing edited announcement voice data therein, and a memory controlling/voice processing circuit for outputting the interrupt signal to the CPU, reading the voice output address data from the DPRAM, outputting the read voice output address data to the fixed voice memory or the edited voice memory, converting parallel announcement voice data from the fixed voice memory or the

Abstract: A communications system employs a high-speed digital link with discrete multiple tone (DMT) the outward paths from a central transmitter/receiver to further transmitter/receivers receiving signals therefrom using one set of carrier frequency channels and the return signal paths using a different set of carrier frequency channels.In one form the central transmitter/receiver is an exchange and the further transmitter/receivers are subscribers connected to the exchange.

Abstract: The present invention relates to a system and method for sending and receiving digital signals in a voice communication system. The system includes a data buffer, a tone detector, a speech encoder, and a transmitting unit. The data buffer receives and stores a digitized signal including voice band tone data and speech data. The tone detector detects the voice band tone data and generates at least one tone packet containing data indicative of the voice band tone data. The speech encoder encodes the speech data into a plurality of compressed speech packets. The transmitting unit in communication with the tone detector and the speech encoder transmits a packet message including tone packets and speech packets over an RF channel. The present invention also relates to a receiver including a speech decoder and a tone generator. The speech decoder decompresses speech packets to generate a digitized speech signal.