Abstract: A signal transfer acceleration system accelerates transfer of an audio signal through a communications channel, such as a telephone line, RF link, or other suitable audio signal communications channel. The connection along the communications channel takes much less time than would be required if the audio signal were played at its normal speed. The signal transfer acceleration system includes a specially designed transmitter system and a specially designed receiver system that are interfaced via the communications channel. The transmitter system includes: (1) a transmitter storage device configured to store the audio signal at a first sample rate; (2) a filter configured to reduce a frequency range of the signal by filtering frequencies from the signal; (3) a transmitter configured to transmit the signal along the communications channel at a second sample rate that is faster than the first sample rate so that the frequency range is expanded while a time period of the transfer is reduced.

Abstract: A system and method is discloded for training echo cancelers during a training sequence of a data connection between a first modern connected to a cellular cordeless phone and a second modem, wherein the cellular cordless phone in operating a microcellular mode as opposed to a cellular mode. In such circumstances, where an intermittent two-wire channel interconnects the microcell base station and a central office associated with the public switched telephone network (PSTN), an offset echo will occur in the remote echo of the second modem and the local echo of the first modem. The offset echoes can be attributed to a radio frequency (RF) delay between the cellular cordless phone and the microcell base station. The first modem can make accommodations for the RF delay by increasing the delay time utilized in setting its near-end echo canceler.

Abstract: A Mobile Switching Center (MSC) includes a cellular modem pool that comprises a number of pairs of modems in which the data terminal equipment (DTE) ports of each modem pair are cross-connected in a "back-to-back" fashion. This allows the two modems of each pair to interchange data via their DTE ports and thereby isolate that portion of the cellular fax call over the cellular communications channel from that portion of the cellular fax call through the public-switched telephone network (PSTN). Fax information is transmitted over both the PSTN-portion of the cellular fax call and the cellular portion of the cellular fax call using standard fax modulation techniques. The cellular-side modem of each modem pair is adapted to recover fax handshaking and data signaling from the received--fax modulated--signal and translate the recovered fax information into non-modulated signals (e.g. AT commands) for application to the corresponding PSTN-side modem of the modem pair.

Abstract: A channel routing manager that is employed by a mobile telecommunications switching office routes voice and data calls over a carrier facility interconnecting a cell site transceiver to the mobile cellular switch and includes first and second channels that utilizes first and second encoding methods, respectively. The channel routing manager comprises a hunt group mechanism including first and second channels, wherein the first channels are sorted together and the second channels are sorted together. In addition, the channel routing manager comprises a control mechanism for routing the voice calls to one of the first channels unless all of the first channels are busy and then routing the voice calls to one of the second channels, and for routing the data calls to one of the second channels unless all of the second channels are busy and then routing the data calls to one of the first channels.

Abstract: The present invention enables a dial modem capable of simultaneous voice and data (SVD) operation and connected to a conventional telephone set to automatically select between SVD operation, analog voice operation and digital data operation when transmitting or receiving communication signals based on the position of the telephone set's hookswitch. The invention includes a hookswitch position detector, connected to the telephone set, for sensing the current position of the hookswitch, and a signal controller, connected to the hookswitch position detector. The signal controller may be configured to enable either of two hookswitch control option settings. The hookswitch control option settings determine the manner in which the controller responds to the current hookswitch position ("on-hook" or "off-hook") detected by the hookswitch position detector.

Abstract: The frame based modulus interleaver is used in a digital communications system. The interleaver uses an algorithm which insures that all of the data blocks which are present in the each input frame are output in a single output frame. This is accomplished, in accordance with the invention, by using a modulus operation to determine the location of each block which is input into the interleaver.

Abstract: A cooperative feedback system is provided for a compensation system associated with, for example, a transmitter or codes, for enabling the compensation system to improve the accuracy of digital signals transmitted to a digital network. The cooperative feedback system is particularly suited for providing feedback to a compensation system for correcting distortion resulting from rob bit signaling (RBS), digital loss, or other types of digital signal degradation. The cooperative feedback system includes a compensation selector in a transmitter (e.g., digital modem, analog modem, codec, etc.) that combines compensations with frames of digital data by way of an addition mechanism to produce modified digital data frames. The transmitter is configured to transmit the modified digital data frames into the digital network. A receiver (e.g., digital modem, analog modem, etc.

Abstract: A Mobile Switching Center (MSC) includes a cellular modem pool that comprises a number of pairs of modems in which the data terminal equipment (DTE) ports of each modem pair are cross-connected in a "back-to-back" fashion. This allows the two modems of each pair to interchange data via their DTE ports and thereby isolate that portion of a cellular fax call over the cellular communications channel from that portion of the cellular fax call through the PSTN. Fax information is transmitted over the PSTN-portion of the cellular fax call using a "1-D" fax compression scheme. However, fax information is transmitted over the cellular-portion of the cellular fax call using a "2-D" fax compression scheme and a data modulation as specified in AT&T Paradyne's "Enhanced Throughput Cellular" (ETC) Protocol. The fax terminal equipment at the cellular end of the cellular fax call is configured to perform fax compression/decompression using the "2-D" fax compression scheme.

Abstract: A cellular modem pool provides a "transparent call progress" feature where each modem pair of the cellular modem pool is coupled to a cross-connect switch, which communicates call progress information between the cellular-side and the PSTN-side during data call setup. The modem pair of the cellular modem pool monitors the call progress information for a data signal provided by a DCE of the calling party, e.g., a predefined fax calling tone. Once the fax calling tone is detected, the modem pair prohibits the opening of the connection provided by the cross-connect switch. This enables the transparent call progress feature for the duration of the fax call thereby routing the fax call around the modem pair.

Abstract: A rob bit compensation system improves the accuracy of digital signals transmitted to a digital network, such as a telephone network, that employs rob bit signaling (RBS) wherein the network periodically robs a bit for its own use. The rob bit compensation system can be employed within the transmit subsystem of a digital modem connected with the digital network that periodically robs a bit every nth frame, where n is, for example, 6, 12, or 24. The system may also be employed in association with the communications path within a coder/decoder (codec) that transmits data to the digital network. A feedback system advises the rob bit compensation system as to which frames of outgoing digital data are to have a bit robbed therefrom by the digital network. The feedback system causes a quantity to be mathematically combined with the digital data corresponding with each RBS frame in order to enhance accuracy of the RBS frames.

Abstract: An adaptive voice and data bandwidth management system is implemented in a subscriber loop to permit higher data rates and adaptive allocation of this increased capacity between multiple applications. The management system communicates digital data across multiple-lines when these lines are not in use by other communication equipment. However, when a request for use of a line by another device is detected, a modem clears down a subscriber line and connects the subscriber line to the appropriate communication device. As a result, simultaneous use of a modem and other communication devices is allowed. Once the other communication device ends its communication session, the system adapts to once again communicate digital data over multiple lines in order to increase the speed and efficiency of the data communication.

Abstract: A system and method are provided for providing non-disruptive diagnostics between a first device and a second device in communication through a virtual circuit of a frame relay network. In accordance with one aspect of the invention, the method defines a diagnostic channel by assigning it a unique channel address, transmits a test command from the first device to the second device across the unique channel address, monitors the unique channel address for a response to the test command, and then evaluates the response to determine whether it reflects a fault in the virtual circuit. In accordance with one embodiment, the test command could be a pattern message, a connectivity request, a start send pattern command, a start loopback command, a start monitor pattern command, and a start send pattern command.

Abstract: A digital subscriber line (DSL) access device management information base (MIB) allows the remote management of a DSL access device by using a constructed enterprise DSL MIB to define a plurality of objects that describe the operation of a DSL access device. These objects are used to monitor the performance of, and if desired, send commands to the DSL access device.

Abstract: A first phase change is introduced to an analog signal based on a symbol specified by a data signal, where the symbol is one of a plurality of symbols in a symbol constellation. The analog signal is added to the data signal to form a combined signal which is transmitted over a communication channel that introduces a channel phase change to the analog and data signals. After transmission through the communication channel, the combined signal comprises a phase changed analog signal and a phase changed data signal. A received symbol is specified by the phase changed data signal, and a phase shift is introduced to the phase changed analog signal based on the identity of the received symbol.

Abstract: A high speed modem for simultaneously transmitting both voice and precoded digital data signals over a single communication channel. The modem is operable to combine a voice signal with a precoded digital data signal for transmission at high speeds, high power levels and low distortion previously attainable by high speed data-only modems. The voice signal is processed using conventional data processing techniques to produce a voice signal and a control signal containing information relating to the coding of the voice signal. The control signal is multiplexed and mapped for transmission with the digital data. Selected bits of the multiplexed data are used to define the rotation of the digital data and to rotate the voice vector. The digital data is precoded to compensate for and minimize noise in the communication channel. The rotated voice vector and the precoded digital data are then combined and transmitted.

Abstract: A cascadable modem apparatus includes a modem housing having a top and a bottom. A plurality of angled feet are attached to the housing bottom in cantilever fashion to define a distal portion of each foot. The feet serve both to support the modem on an platform as well as to attach the modem to a similarly configured, adjacent modem assembly. In the preferred embodiment, a plurality of receiving slots are defined in the housing top and are correspondingly disposed to receive the distal portions of a plurality of angled feet from an adjacent modem housing. In this way, insertion of the distal portions of the feet snugly into the receiving slots of an adjacent modem effectively attaches the two adjacent modem assemblies. Preferably, a resilient locking tab is attached to the housing bottom in cantilever fashion to define a distal portion directed away from the housing bottom. As a result, the tab is responsive to force applied to the distal portion to flex inwardly toward the housing bottom.

Abstract: Digital data is encoded using a modulus m converter to produce fractionally encoded words, where m is the nearest integer larger than 2.sup.c and c is a noninteger. The fractionally encoded words are mapped into a symbol constellation having m symbols to produce a two dimensional data signal. The data signal is added to a two dimensional analog signal, which was obtained by encoding an input analog signal, to produce a combined two dimensional signal. The combined signal is modulated using QAM and then transmitted over a communication channel.

Abstract: A system and method for establishing a link layer connection between a calling modem having a plurality of possible first physical layer modulations and one or more possible link layer connections and an answering modem having a plurality of possible second physical layer modulations and one or more possible link layer connections comprising the steps of establishing a physical layer connection between the calling and the answering modems, wherein the physical layer connection is based on a negotiated physical layer modulation chosen from the first and second physical layer modulations, and establishing link layer connection based upon said negotiated physical layer modulation. The link layer connection includes parameters that are preset to default values based upon the negotiated physical layer connection. Thus, the modems are able to avoid the link layer negotiation, thereby providing a faster and more robust connection.