Conexant Systems, Inc.

Mindspeed Technologies, Inc.

Keith T Chu

Sverrir Olafsson

Burk Beadle

Li Chen

Skantha Kandiah

Jason Brent

Wei Kang Tsai

Mohammad Reza Zad-Issa

Paul C Wren

Michael S Beadle

Zhihui Chen

Thomas C Liau

Hundraj S Gopal

Frank Chen

Frank B Hansen

Farhad Aminian

There is provided a method of quantifying a voice quality in a telecommunication system including a first gateway in communication with a second gateway over a packet network. The method comprises deriving speech parameters from a first speech signal of a first talker received by the first gateway over a first communication line and a second speech signal of a second talker received by the first gateway from the second gateway over the packet network, determining a conversational impairment index using the speech parameters, deriving technology parameters based on voice technology and components in the telecommunication system, determining a technology impairment index using the technology parameters, and mapping the conversational impairment index and the technology impairment index into a conversational quality index to quantify the voice quality in the telecommunication system.

Method and apparatus for quantifying, predicting and monitoring the conversational quality

A modem detection method is provided for use by a first gateway, the first gateway capable of communicating with a second gateway over a packet network. The method comprises setting the first gateway to a voice mode having a first coding scheme, encoding an input signal using the first coding scheme to generate a first encoded input signal, transmitting the first encoded input signal to the second gateway over the packet network, looking for a first tone in the input signal while the first gateway is in the voice mode, wherein the first tone is indicative of a beginning of a character, detecting the first tone in the input signal; setting the first gateway from the voice mode to a modem mode in response to the detecting; and transmitting the input signal to the second gateway according to the modem mode.

Text telephone modem communications over packet networks

Answer tone received at answering-side gateway and first classification signal is transmitted to a calling-side gateway that generates an answer tone in response to the signal. A second classification signal may be transmitted to the calling-side gateway that adjusts the answer tone in response to the second signal.

Method and apparatus for low-latency, semantic conveyance of an answer tone over a data network

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.

Method and apparatus for fast V.90 modem startup

An apparatus and method for configuring a gateway device for a modem over packet network session is disclosed. For example, a system may include a first gateway device coupled to a first client device and a second gateway device coupled to a second client device, where the first gateway device is coupled to the second gateway device over a packet network. The trans-compression types and capabilities of the first and second gateway devices are determined and used to generate a set of negotiation parameters. The first gateway device then negotiates with the first client device using the negotiation parameters to select a first compression algorithm. A second compression algorithm selected between the second gateway device and the second client devices is also determined by the first gateway device. Then, the trans-compression mode of operation of the first gateway device is configured based on the trans-compression types and capabilities of the first and second gateway devices and the selected first and second compression algorithms. The second gateway device may be similarly configured.

Trans-compression selection and configuration in modem over packet networks

Various methods and systems for establishing modem relay connections are provided. For example, a modem relay method for use by a first gateway device in communication with a calling modem comprises the exemplary steps of: receiving a call from the calling modem for establishing a communication with a remote modem; requesting a second gateway device to place a call to the remote modem for establishing the communication; transmitting ANSam to the calling modem for a predetermined period of time according to an ANSam message received from the second gateway device in an RFC2833 message via a packet network; monitoring for detection of a CM signal from the calling modem; monitoring for detection of an AA signal from the calling modem; monitoring for receipt of a modulation type message from the second gateway device; and monitoring for receipt of a pass through mode message from the second gateway device.

Modem relay over a packet network

A communications system includes an internet protocol network, a calling modem and an answering modem configured to effectively handle network latency. The calling modem includes a timer storing a network latency value. The network latency value is compared to a network latency threshold. If the network latency threshold is less than the network latency value, then a high speed modem connection is continued. If the network latency value is greater than the network latency threshold, then the high speed modem connection is terminated. In place of the high speed modem connection, a low speed modem connection is established. The calling modem is operable to transmit a modem connection selection signal for selecting a high speed modem connection or a low speed modem connection. The answering modem is operable to receive the modem connection selection signal.

Network latency recovery for internet gateways

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 &ldquo;match&rdquo; 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.

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. In the case that one of either the client or the server only supports nonlinear mode, the server informs the client that nonlinear PCM is to be employed. Assuming that linear PCM is specified as the data communications mode between the client and the server, the server then transmits a message to the line card that informs the line card that linear PCM is to be used.

System and method for selecting a data transmission mode

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 (&ldquo;FAX-over-IP&rdquo;) 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.

Extending symbol rates and symbol rate re-negotiation for facsimile modems

An apparatus and method for minimizing nonlinear distortions in computer system communications where the upstream signal from a client modem to a server modem is periodically sampled, the samples being utilized by a non-linear decision feedback equalizer to periodically produce sets of equalizer coefficients. The equalizer coefficients are sent via an independent communication channel downstream to the client modem to continuously update distortion-minimizing adjustments to the client modem's upstream output. The samples are taken periodically in order to update the non-linear decision feedback equalizer so that it can provide appropriate equalizer coefficients for the changing characteristics of the upstream signal. The method includes identifying, by a first communication system, nonlinear equalization parameters to be used by a second communication system to minimize nonlinear distortions on a primary communication channel. The method also includes transmitting, by the first communication system, the nonlinear equalization parameters to the second communication system by a secondary communication channel. In addition, the method includes receiving, by the second communication system, the nonlinear equalization parameters from the first communication system. Finally, the method includes utilizing, by the second communication system, the nonlinear equalization parameters to minimize nonlinear distortion on the primary communication channel.

Non-linear equalization for the upstream data connection of 56K PCM modems

A half-duplex facsimile modem system according to the present invention may exhibit a shorter startup time relative to conventional systems. The modem system exchanges capabilities information concurrently with the transmission of a conventional answer signal, thus obviating the need for performing a separate capabilities exchange procedure. In addition, the modem system is capable of determining a preferred training sequence duration based upon one or more characteristics of the current channel. The preferred training sequence duration is communicated from the answer modem to the calling modem such that the calling modem can format the training sequence in an appropriate manner. The resultant training sequence has a time duration that is variable in response to, e.g., the signal-to-noise ratio of the instant channel. These techniques can result in a significant reduction in the startup latency typically associated with conventional half-duplex facsimile modem systems.

Method and apparatus for quick startup in a half-duplex modem system

A communication system that includes a first modem and a second modem that establishes a communication link between the first modem and the second modem. The communication link has a first set of communication characteristics including a first communication channel or group of communication channels through which at least data is exchanged and a second communication channel through which no data is exchanged. Either the first modem or the second modem is configured to signal for a change, via the second communication channel, in the first set of communication characteristics.

Seamless transition between communication characteristics of communication devices

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.

Growing community of inventors

Mission Viejo, CA, United States of America

Keith T Chu