Abstract: 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 determine whether the quick connect protocol is supported. If so, then the called modem transmits a modified answer tone to the calling modem. The calling modem analyzes the signal received in response to the modified answer tone to determine whether characteristics of the current channel are similar to stored characteristics associated with a previous connection over the same channel. If a channel “match” is found, then the modem devices carry out a quick initialization routine that eliminates, abbreviates, or modifies a number of procedures or protocols that are carried out in conventional modem startup processes.

Abstract: 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 determine whether the fast connect protocol is supported. If so, then the called modem transmits a modified answer tone to the calling modem. The calling modem analyzes the signal received in response to the modified answer tone to determine whether characteristics of the current channel are similar to stored characteristics associated with a previous connection over the same channel. If a channel “match” is found, then the modem devices carry out a fast initialization routine that eliminates, abbreviates, or modifies a number of procedures or protocols that are carried out in conventional modem startup processes.

Abstract: 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-determined period of time in response to receiving the instruction, where the tonal signal identifies the POS modem as being capable of supporting the fast train protocol; receiving an S signal from the remote modem in response to transmitting the tonal signal; receiving an S\ signal from the remote modem following receiving the S signal; receiving one or more remote PP signals from the remote modem following receiving the S\ signal; and receiving a remote parameter sequence from the remote modem following receiving the one or more remote PP signals.

Abstract: 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 determine whether the quick connect protocol is supported. If so, then the called modem transmits a modified answer tone to the calling modem. The calling modem analyzes the signal received in response to the modified answer tone to determine whether characteristics of the current channel are similar to stored characteristics associated with a previous connection over the same channel. If a channel “match” is found, then the modem devices carry out a quick initialization routine that eliminates, abbreviates, or modifies a number of procedures or protocols that are carried out in conventional modem startup processes.

Abstract: 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 establish a specific data communications mode. The data communications mode may be, for example, linear pulse code modulation (PCM) or nonlinear PCM. To begin, the client informs the server whether it supports nonlinear PCM, linear PCM, or both. In light of the clients communications capability and the modes supported by the server itself, the server responds by informing the client which data communications mode is to be used. In the case that both the client and server support linear and nonlinear PCM, the server informs the client that linear PCM is to be used, such being more conducive to accurate high-speed data communication.

Abstract: 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 determine whether the quick connect protocol is supported. If so, then the called modem transmits a modified answer tone to the calling modem. The calling modem analyzes the signal received in response to the modified answer tone to determine whether characteristics of the current channel are similar to stored characteristics associated with a previous connection over the same channel. If a channel “match” is found, then the modem devices carry out a quick initialization routine that eliminates, abbreviates, or modifies a number of procedures or protocols that are carried out in conventional modem startup processes.

Abstract: 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 determine whether the quick connect protocol is supported. If so, then the called modem transmits a modified answer tone to the calling modem. The calling modem analyzes the signal received in response to the modified answer tone to determine whether characteristics of the current channel are similar to stored characteristics associated with a previous connection over the same channel. If a channel “match” is found, then the modem devices carry out a quick initialization routine that eliminates, abbreviates, or modifies a number of procedures or protocols that are carried out in conventional modem startup processes.

Abstract: 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 central office. The APCM modem further transmits an on hold notification to the DPCM modem to prevent the DPCM modem from terminating the communication session as a result of the interruption by the alert signal and/or receipt of the caller ID data by the APCM modem. The DPCM modem is placed on hold while the APCM modem answers the call waiting. Subsequently, the APCM modem initiates a quick connect procedure to re-establish the communication session with the DPCM modem.

Abstract: 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 modem's symbol rate from the current maximum of 3429 symbols per second standard to a higher rate of symbol transmission can quickly enhance throughput. The technique is useful for fast primary channel retrains and for situations in which symbol rates are to be reduced. The technique is also useful for changing the requested symbol rate with data rate negotiation in situations in which data rate selection for the new symbol rate may not be known.

Abstract: 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, which may include wired and/or wireless telephone devices, videophone devices, facsimile devices, or the like. The customer premise may also support any number of conventional POTS telephony instruments. The voice/data server and the enhanced telephony devices communicate signaling data therebetween via a signaling technique such as the V.21 modem protocol. The signaling information conveys data associated with the status of the enhanced telephony devices, calling party and called party identification, characteristics of the incoming and outgoing calls, and/or data related to any number of operating parameters and characteristics of the system.

Abstract: 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 suitable constellation is derived. In one embodiment, an optimum least-squares algorithm is employed. In an alternate embodiment, a least mean squares (LMS) or normalized LMS algorithm is performed.

Abstract: 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 information sequence including all the necessary communication information. Subsequently, the communication systems start transmitting short sequences, including an acknowledgement information portion. If one of the communication systems does not receive an acknowledgement within a predetermined time or event, that communication system may retransmit another long information sequence. After such retransmission, the retransmitting communication system may continue transmitting the long information sequences or may start transmitting the short sequences once again. Eventually, each of the communication systems should receive a long information sequence and acknowledge their receipt of such sequence.

Abstract: 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 information sequence including all the necessary communication information. Subsequently, the communication systems start transmitting short sequences, including an acknowledgement information portion. If one of the communication systems does not receive an acknowledgement within a predetermined time or event, that communication system may retransmit another long information sequence. After such retransmission, the retransmitting communication system may continue transmitting the long information sequences or may start transmitting the short sequences once again. Eventually, each of the communication systems should receive a long information sequence and acknowledge their receipt of such sequence.

Abstract: 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 information sequence including all the necessary communication information. Subsequently, the communication systems start transmitting short sequences, including an acknowledgement information portion. If one of the communication systems does not receive an acknowledgement within a predetermined time or event, that communication system may retransmit another long information sequence. After such retransmission, the retransmitting communication system may continue transmitting the long information sequences or may start transmitting the short sequences once again. Eventually, each of the communication systems should receive a long information sequence and acknowledge their receipt of such sequence.

Abstract: 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 of the invention provides a faster and more accurate evaluation of the channel. Another embodiment of the invention comprises processing of the received sequence to determine a desired or maximum data rate for the line or channel. The invention also provides an evaluation and calculation of the noise on the line or channel.

Abstract: 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 telecommunication wires, as a common wire for each of the N−1 wires. In addition, the DC voltage polarities of at least one of the N−1 telecommunication wires may be reversed to reduce the likelihood of overloading the common wire. The wiring scheme may be utilized in the context of many data transmission systems including: POTS, PSTN, DSL, data modems, facsimile modems, and ISDN. The wiring scheme of the present invention may achieve higher data rates for data transmission.

Abstract: 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 point constellations designed by the client modem is also calculated by the server modem to verify that the transmit power limit imposed upon the server modem is not exceeded. In addition, the modem system is capable of designating a transmit power limit associated with one or more training signal points or a training sequence for use during a training mode.

Abstract: 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 of the invention provides a faster and more accurate evaluation of the channel. Another embodiment of the invention comprises processing of the received sequence to determine a desired or maximum data rate for the line or channel. The invention also provides an evaluation and calculation of the noise on the line or channel.

Abstract: 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 for symbols transmitted by the first modem during a training sequence. The specific parameters of the synchronization signal format may be associated with the design and operation of the second modem. For example, the particular timing recovery and automatic gain control schemes used by the receiver portion of the second modem may be optimally initialized with a synchronization signal having a specific length, amplitude, or spectrum. In one embodiment, a synchronization signal is configured to convey a single frequency tone for use during a synchronization routine. The modem system may also employ similar techniques to generate, transmit, and analyze a programmable line impairment learning signal.

Abstract: 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 control data. The control signal includes a predetermined header section that is monitored by the receiving modem to maintain frame synchronization and to correct for digital frame slippage. The control signal also includes a number of control data packets that contain information related to the initiation of control procedures such as rate renegotiations and retraining requests. The disclosed inband transmission techniques may additionally (or alternatively) be utilized to define a secondary data channel.