| Patent Number |
Title Of Patent |
Date Issued |
| RE39165 |
Method and apparatus for training linear equalizers in a PCM modem |
July 11, 2006 |
| A pulse code modulation (PCM) modem system employs a relatively white training signal to optimize the adaptive filter coefficients in the receiver equalizers. During the training mode, any line coding or equivalent spectral shaping is disabled to provide a training signal sequence ha |
| RE38678 |
Method and apparatus for synchronizing a data communications system to a periodic digital impair |
December 28, 2004 |
| A pulse code modulation modem system is configured to transmit data from a first modem to a second modem over the public switched telephone network (PSTN). The PSTN employs robbed bit signaling (RBS) such that symbols affected by RBS arrive at the second modem in a periodic manner based |
| 7587034 |
Use of modem on hold for network management and telephone access |
September 8, 2009 |
| A modem to modem communication system supports call waiting services by exchanging hold request and acknowledge signals before relinquishing the line servicing incoming calls. Thereafter, the modem to modem session is reestablished without having to redial. The hold request may be denied |
| 7443966 |
Using modems to place modem connections on hold and to maintain upper layer network connection |
October 28, 2008 |
| A modem to modem communication system supports call waiting services by exchanging hold request and acknowledge signals before relinquishing the line servicing incoming calls. Thereafter, the modem to modem session is reestablished without having to redial. The hold request may be denied |
| 7305072 |
Method and apparatus for quick modern reconnect |
December 4, 2007 |
| A quick startup procedure for a modem system utilizes known characteristics of a previously established communication channel to reduce the initialization period associated with subsequent connections over the same channel. In response to the establishment of a call, the modem device |
| 7277531 |
Method and apparatus for fast V.90 modem startup |
October 2, 2007 |
| A fast startup procedure for a modem system utilizes known characteristics of a previously established communication channel to reduce the initialization period associated with subsequent connections over the same channel. In response to the establishment of a call, the modem devices |
| 7203241 |
Methods and apparatus for adaptive PCM level estimation and constellation training |
April 10, 2007 |
| Systems compensate for the presence of digital impairments using adaptive constellation techniques. Sample magnitudes are estimated from received samples transmitted during a training period using an algorithm based on minimizing the sum of squares of the estimated errors, afterwhich a |
| 7062022 |
Method and apparatus for fast V.90 modem startup |
June 13, 2006 |
| A fast startup procedure for a modem system utilizes known characteristics of a previously established communication channel to reduce the initialization period associated with subsequent connections over the same channel. In response to the establishment of a call, the modem devices |
| 7027573 |
Method and apparatus for quick modem reconnect |
April 11, 2006 |
| A quick startup procedure for a modem system utilizes known characteristics of a previously established communication channel to reduce the initialization period associated with subsequent connections over the same channel. In response to the establishment of a call, the modem device |
| 6985566 |
Point of sale modem for high-speed communications |
January 10, 2006 |
| A fast train protocol for use by a high-speed point of sale (POS) modem is disclosed. In one aspect, the fast train protocol may include he following exemplary steps: receiving an instruction to connect to a remote modem; transmitting a tonal signal to the remote modem for a pre-dete |
| 6975585 |
Slotted synchronous frequency division multiplexing for multi-drop networks |
December 13, 2005 |
| In a modulation system an efficient modulation at a master station and allows great flexibility in clients, from simple 2 bit/symbol single-channel modulation and demodulation to multi-channel multiple-bit modulation. The present invention also permits selection of the frequency band |
| 6928107 |
Iterative precoding system and method for resource limited data transceivers |
August 9, 2005 |
| A system and method for training an equalizer structure of a digital data communication system in order to compensate for transmission impairments on the line particularly wherein one transceiver of the two is resource limited. In an exemplary embodiment, a line card provides equalizatio |
| 6922467 |
Quick connect parameter exchange |
July 26, 2005 |
| The startup, retrain, renegotiation quick connect or other processes of handshaking between communication systems involve the exchange of certain modulation, constellation, precoder, prefilter and other communication related information. The communication systems exchange one long in |
| 6912276 |
Modem on hold |
June 28, 2005 |
| A modem to modem communication system supports call waiting services by exchanging hold request and acknowledge signals before relinquishing the line servicing incoming calls. Thereafter, the modem to modem session is reestablished without having to redial. The hold request may be denied |
| 6842509 |
Signaling mechanism for modem connection holding and reconnecting |
January 11, 2005 |
| A quick startup procedure for a modem system utilizes known characteristics of a previously established communication channel to reduce the initialization period associated with subsequent connections over the same channel. In response to the establishment of a call, the modem devices |
| 6829293 |
Method and apparatus for line probe signal processing |
December 7, 2004 |
| A system, method, and signal are disclosed for line probing. The invention provides an improved signal for line probing having desirable characteristics. In various embodiments the signal comprises a periodic sequence having good autocorrelation characteristics. The periodic sequence |
| 6819749 |
Method and apparatus for fast V.90 modem startup |
November 16, 2004 |
| A fast startup procedure for a modem system utilizes known characteristics of a previously established communication channel to reduce the initialization period associated with subsequent connections over the same channel. In response to the establishment of a call, the modem devices |
| 6785371 |
Signaling mechanism for modem connection holding and reconnecting |
August 31, 2004 |
| A quick startup procedure for a modem system utilizes known characteristics of a previously established communication channel to reduce the initialization period associated with subsequent connections over the same channel. In response to the establishment of a call, the modem devices |
| 6744819 |
System and method for selecting a data transmission mode |
June 1, 2004 |
| Various systems and methods are provided in a client, a line card or other conversion device, and a server to implement either a linear or a nonlinear PCM transmission mode for data communication in a data communications network. The client and the server negotiate with each other to |
| 6731726 |
Communication on hold |
May 4, 2004 |
| A communication session is established between an APCM modem and a DPCM modem. The central office interrupts the communication session by transmitting a call-waiting alert signal to the APCM modem. In response to the alert signal, the APCM modem transmits a caller ID data request to the |
| 6728308 |
Extending symbol rates and symbol rate re-negotiation for facsimile modems |
April 27, 2004 |
| Half-duplex mode in V.34 facsimile modems can be exploited using symbol rate re-negotiation to enhance performance and throughput. The enhancement is useful for facsimile servers and for facsimile transmission over Internet Protocol ("FAX-over-IP") network applications. Extending the |
| 6724870 |
System and method for distributing enhanced telephony service to customer premises equipment |
April 20, 2004 |
| A telephony services distribution system includes a voice/data server that receives and transmits telephony data in accordance with a suitable digital communication protocol. The voice/data server is associated with a customer premise that supports a number of enhanced telephony devices, |
| 6721279 |
Method and apparatus for adaptive PCM level estimation and constellation training |
April 13, 2004 |
| Systems compensate for the presence of digital impairments using adaptive constellation techniques. Sample magnitudes are estimated from received samples transmitted during a training period using an algorithm based on minimizing the sum of squares of the estimated errors, after which a |
| 6704399 |
Quick connect parameter exchange |
March 9, 2004 |
| The startup, retrain, renegotiation quick connect or other processes of handshaking between communication systems involve the exchange of certain modulation, constellation, precoder, prefilter and other communication related information. The communication systems exchange one long in |
| 6693998 |
Error correction and compression parameter exchange during modem training phase |
February 17, 2004 |
| The startup, retrain, renegotiation quick connect or other processes of handshaking between communication systems involve the exchange of certain modulation, constellation, precoder, prefilter and other communication related information. The communication systems exchange one long in |
| 6693992 |
Line probe signal and method of use |
February 17, 2004 |
| A system, method, and signal are disclosed for line probing. The invention provides an improved signal for line probing having desirable characteristics. In various embodiments the signal comprises a periodic sequence having good autocorrelation characteristics. The periodic sequence |
| 6678375 |
Efficient use of wire for data communication systems |
January 13, 2004 |
| The present invention uses a wiring scheme for data transmission. The wiring scheme includes designating N-1 telecommunication wires and a common wire to each carry N-1 signals. The wiring scheme further includes designating one telecommunication wire, other than the N-1 telecommunic |
| 6570932 |
Calculation and verification of transmit power levels in a signal point transmission system |
May 27, 2003 |
| A pulse code modulation modem system utilizes the same total average transmit power formula for designing signal point constellations and for verifying that the transmit power of the signal point constellations are within a designated maximum power limit. The transmit power of the signal |
| 6504886 |
Communication of an impairment learning sequence according to an impairment learning sequence de |
January 7, 2003 |
| A modem system includes a programmable synchronization signal format that can be configured at a first modem in response to a request received from a second modem. The synchronization signal format may define a number of parameters of the synchronization signal, such as the sign pattern |
| 6480533 |
Method and apparatus for receiving control signals in a data communication system having a fully |
November 12, 2002 |
| A modem system having two modem devices digitally connected to a digital telephone network includes an inband control signal channel. The inband control signal channel is formed by using the most significant bit position of every sixth transmitted codeword for the transmission of con |
| 6434233 |
Method and apparatus for canceling periodic interference signals in a digital data communication |
August 13, 2002 |
| A tone predictor may be employed in a modem system to cancel periodic interference components present in a received signal. The tone predictor may be implemented in a receiver arrangement to cancel such periodic interference and to condition a decision error signal utilized to update |
| 6421375 |
Method and apparatus for transmitting control signals in a data communication system having a fu |
July 16, 2002 |
| A modem system having two modem devices digitally connected to a digital telephone network includes an inband control signal channel. The inband control signal channel is formed by using the most significant bit position of every sixth transmitted codeword for the transmission of con |
| 6414990 |
Timing recovery for a high speed digital data communication system based on adaptive equalizer i |
July 2, 2002 |
| A preferred timing recovery scheme is particularly suitable for a high speed digital data communication system that employs T-spaced equalization in the receiving device, where echo cancellation occurs after equalization. The timing recovery technique is based upon an analysis of the |
| 6414989 |
Upstream PCM transmission for a modem system |
July 2, 2002 |
| A modem system utilizes PCM encoding and transmission techniques in the upstream direction from a client modem (connected to a digital network via an analog loop) to a central site modem (connected to the digital network via a digital link). The modem system employs precoding techniques |
| 6359932 |
Verification of transmit power levels in a signal point limited transmission system |
March 19, 2002 |
| A pulse code modulation modem system utilizes the same total average transmit power formula for designing signal point constellations and for verifying that the transmit power of the signal point constellations are within a designated maximum power limit. The transmit power of the signal |
| 6332009 |
Method and apparatus for generating a line impairment learning signal for a data communication s |
December 18, 2001 |
| A modem system includes a programmable synchronization signal format that can be configured at a first modem in response to a request received from a second modem. The synchronization signal format may define a number of parameters of the synchronization signal, such as the sign pattern |
| 6317419 |
Method and apparatus for training an echo canceler in a PCM modem context |
November 13, 2001 |
| An improved echo canceler training technique may be employed by a digital server modem in a PCM modem context, such as a V.90 modem system. The disclosed echo canceler training technique establishes the digital impairments within the echo path by transmitting a training signal from a |
| 6259742 |
Methods and apparatus for optimizing shell mapping techniques using an approximated power cost f |
July 10, 2001 |
| To compensate for the substantially non-uniform spacing of constellation points in a pulse code modulation modem, the transmitting power efficiency is substantially maximized while substantially limiting the complexity of the mapping. To optimize the transmitting power efficiency, the pr |
| 6226334 |
Methods and apparatus for implementing shell mapping techniques in the context of a PCM-based mo |
May 1, 2001 |
| An improved apparatus for implementing shell mapping in a PCM modem incorporates u-law signal mapping points. An improved signal point encoding technique effectively employs ring-indices that are generated in accordance with known principles. The ring indices are applied to a reorder |
| 6212247 |
Method and apparatus for generating a programmable synchronization signal for a data communicati |
April 3, 2001 |
| A modem system includes a programmable synchronization signal format that can be configured at a first modem in response to a request received from a second modem. The synchronization signal format may define a number of parameters of the synchronization signal, such as the sign pattern |
| 6163570 |
Methods and apparatus for verifying transmit power levels in a signal point limited transmission |
December 19, 2000 |
| A pulse code modulation modem system utilizes the same total average transmit power formula for designing signal point constellations and for verifying that the transmit power of the signal point constellations are within a designated maximum power limit. The transmit power of the signal |
| 6081567 |
Method and apparatus for synchronizing a data communication system to a periodic digital impairm |
June 27, 2000 |
| A pulse code modulation modem system is configured to transmit data from a first modem to a second modem over the public switched telephone network (PSTN). The PSTN employs robbed bit signaling (RBS) such that symbols affected by RBS arrive at the second modem in a periodic manner based |
| 6023493 |
Method and apparatus for synchronizing a data communication system to a periodic digital impairm |
February 8, 2000 |
| A pulse code modulation modem system is configured to transmit data from a first modem to a second modem over the public switched telephone network (PSTN). The PSTN employs robbed bit signaling (RBS) such that symbols affected by RBS arrive at the second modem in a periodic manner based |
| 5970100 |
System for controlling and shaping the spectrum and redundancy of signal-point limited transmiss |
October 19, 1999 |
| Methods and apparatus are disclosed for shaping and controlling the spectrum of transmitted samples with a set of predetermined frequency characteristics and a predetermined set of allowable transmitted signal levels are disclosed. In particular, methods of minimizing the energy of t |
