公开(公告)号：US06744819B1

公开(公告)日：2004-06-01

申请号：US09656804

申请日：2000-09-07

申请人： Keith T. Chu ,  Sverrir Olafsson

发明人： Keith T. Chu ,  Sverrir Olafsson

IPC分类号： H04B1404

CPC分类号： H04B14/04

摘要： 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.

摘要翻译： 在客户机，线路卡或其他转换设备中提供各种系统和方法，以及服务器，以实现用于数据通信网络中的数据通信的线性或非线性PCM传输模式。 客户端和服务器进行协商，建立特定的数据通信模式。 数据通信模式可以是例如线性脉码调制（PCM）或非线性PCM。 首先，客户端通知服务器是否支持非线性PCM，线性PCM或两者。 鉴于客户端的通信能力和服务器本身支持的模式，服务器通过向客户端通知要使用哪种数据通信模式进行响应。 在客户端和服务器都支持线性和非线性PCM的情况下，服务器通知客户端将使用线性PCM，从而更有利于准确的高速数据通信。 在客户机或服务器之一仅支持非线性模式的情况下，服务器通知客户端将使用非线性PCM。 假设线性PCM被指定为客户端和服务器之间的数据通信模式，则服务器然后向线卡发送消息，通知线路卡将使用线性PCM。

公开(公告)号：US06728308B1

公开(公告)日：2004-04-27

申请号：US09409369

申请日：1999-09-30

申请人： Keith T. Chu ,  Sverrir Olafsson

发明人： Keith T. Chu ,  Sverrir Olafsson

IPC分类号： H04B138

CPC分类号： H04L5/1446 ,  H04L1/0003

摘要： 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.

摘要翻译： V.34传真调制解调器中的半双工模式可以利用符号速率重新协商来提高性能和吞吐量。 该增强功能对于传真服务器和通过因特网协议（“传真IP”）网络应用程序的传真传输非常有用。 将调制解调器的符号速率从目前每秒3429符号每秒标准扩展到更高的符号传输速率可以快速提高吞吐量。 该技术对于快速主信道再训练和符号速率降低的情况很有用。 在新符号率的数据速率选择可能不知道的情况下，该技术对于在数据速率协商中改变所请求的符号率也是有用的。

公开(公告)号：US06272170B1

公开(公告)日：2001-08-07

申请号：US09112433

申请日：1998-07-09

申请人： Keith T. Chu

发明人： Keith T. Chu

IPC分类号： H04B138

CPC分类号： H04L5/1438 ,  H04L69/24 ,  H04M11/06

摘要： A modem system start-up routine is performed in an improved manner such that information related to the exchange of the operational capabilities of the modem devices is transmitted at a higher data rate than prior art systems. A transition protocol is utilized to enable the modem system to seamlessly shift operating modes during the start-up routine. An initial data rate is utilized to transmit initial capabilities exchange data near the beginning of the start-up routine. Next, an initial training procedure is conducted to train the receive modem for operation at an intermediate data rate. The exchange of operational capabilities occurs at this intermediate data rate. Eventually, the modem system shifts to the primary data rate utilized during the normal data transmission mode. A final training procedure is performed to tune the receive modem in a more precise manner in response to the primary data rate. The overall effect of the improved start-up routine is a reduction in the start-up latency time.

摘要翻译： 以改进的方式执行调制解调器系统启动程序，使得与调制解调器装置的操作能力的交换相关的信息以比现有技术系统更高的数据速率被传送。 使用转换协议来使得调制解调器系统在启动例程期间无缝地移动操作模式。 利用初始数据速率在启动程序开始附近传送初始能力交换数据。 接下来，进行初始训练程序以训练接收调制解调器以中间数据速率进行操作。 操作能力的交换以这种中间数据速率发生。 最终，调制解调器系统转移到在正常数据传输模式期间使用的主数据速率。 执行最终训练程序以响应于主数据速率以更精确的方式调谐接收调制解调器。 改进的启动程序的整体效果是启动延迟时间的减少。

公开(公告)号：US07411941B2

公开(公告)日：2008-08-12

申请号：US11036627

申请日：2005-01-13

申请人： Keith T. Chu ,  Jason B. Brent

发明人： Keith T. Chu ,  Jason B. Brent

IPC分类号： H04L12/28

CPC分类号： H04L12/66 ,  H04L29/06 ,  H04L69/18 ,  H04M11/06

摘要： 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.

摘要翻译： 提供调制解调器检测方法供第一网关使用，第一网关能够通过分组网络与第二网关进行通信。 该方法包括将第一网关设置为具有第一编码方案的语音模式，使用第一编码方案对输入信号进行编码以产生第一编码输入信号，通过分组网络将第一编码输入信号发送到第二网关，查找 当所述第一网关处于所述语音模式时，对于所述输入信号中的第一音调，其中所述第一音调表示字符的开始，检测所述输入信号中的所述第一音调; 响应于检测将第一网关从语音模式设置为调制解调器模式; 以及根据调制解调器模式将输入信号发送到第二网关。

公开(公告)号：US06650698B1

公开(公告)日：2003-11-18

申请号：US09408367

申请日：1999-09-29

申请人： Thomas C. Liau ,  Keith T. Chu ,  Wei K. Tsai

发明人： Thomas C. Liau ,  Keith T. Chu ,  Wei K. Tsai

IPC分类号： H03K5159

CPC分类号： H04L25/4927 ,  H04L2025/03363

摘要： 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.

摘要翻译： 一种用于使来自客户端调制解调器到服务器调制解调器的上行信号周期性地采样的计算机系统通信中的非线性失真最小化的装置和方法，由非线性判决反馈均衡器利用的采样周期性地产生均衡器系数集合。 均衡器系数通过下游的独立通信信道发送到客户端调制解调器，以连续地更新对客户端调制解调器的上行输出的失真最小化调整。 定期取样，以便更新非线性判决反馈均衡器，使得它可以为上游信号的变化特性提供适当的均衡器系数。 该方法包括由第一通信系统识别由第二通信系统使用的非线性均衡参数，以使主通信信道上的非线性失真最小化。 该方法还包括由第一通信系统通过辅助通信信道将非线性均衡参数发送到第二通信系统。 此外，该方法包括由第二通信系统接收来自第一通信系统的非线性均衡参数。 最后，该方法包括由第二通信系统利用非线性均衡参数来最小化主通信信道上的非线性失真。

公开(公告)号：US08184537B1

公开(公告)日：2012-05-22

申请号：US11700698

申请日：2007-01-30

申请人： Hundraj S. Gopal ,  Mohammad Reza Zad-Issa ,  Keith T. Chu

发明人： Hundraj S. Gopal ,  Mohammad Reza Zad-Issa ,  Keith T. Chu

IPC分类号： H04L12/26 ,  H04L12/66

CPC分类号： H04M7/1205 ,  H04L43/0864 ,  H04L65/80 ,  H04M3/2236

摘要： 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.

摘要翻译： 提供了一种在电信系统中量化语音质量的方法，包括通过分组网络与第二网关通信的第一网关。 该方法包括从第一通信网络通过第一通信线路接收的第一通话者的第一语音信号和由第一网关从第二网关通过分组网络接收的第二讲话者的第二语音信号，从分组网络导出语音参数， 使用语音参数的对话性损伤指标，基于电话系统中的语音技术和组件的技术参数的导出，使用技术参数确定技术损害指数，并将会话性损耗指数和技术损害指数映射到对话质量指标中以量化 电信系统中的语音质量。

公开(公告)号：US07046382B1

公开(公告)日：2006-05-16

申请号：US09345269

申请日：1999-06-30

申请人： Keith T. Chu

发明人： Keith T. Chu

IPC分类号： G06F15/00 ,  H04L12/56 ,  H04B1/38

CPC分类号： H04N1/32614 ,  H04L12/66 ,  H04L29/06 ,  H04L47/10 ,  H04L47/283 ,  H04L69/24 ,  H04L69/28 ,  H04M11/06 ,  H04N1/00209 ,  H04N1/00281 ,  H04N1/00312 ,  H04N1/32683 ,  H04N2201/0024 ,  H04N2201/0025

摘要： 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.

摘要翻译： 通信系统包括互联网协议网络，主叫调制解调器和被配置为有效地处理网络等待时间的应答调制解调器。 呼叫调制解调器包括存储网络延迟值的定时器。 将网络延迟值与网络延迟阈值进行比较。 如果网络延迟阈值小于网络延迟值，则继续进行高速调制解调器连接。 如果网络延迟值大于网络延迟阈值，则终止高速调制解调器连接。 代替高速调制解调器连接，建立低速调制解调器连接。 呼叫调制解调器可操作地发送用于选择高速调制解调器连接或低速调制解调器连接的调制解调器连接选择信号。 应答调制解调器可操作以接收调制解调器连接选择信号。

公开(公告)号：US07349383B2

公开(公告)日：2008-03-25

申请号：US10253352

申请日：2002-09-24

申请人： Keith T. Chu

发明人： Keith T. Chu

IPC分类号： H04L12/56 ,  H04L12/66

CPC分类号： H04M11/06

摘要： 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.

摘要翻译： 应答侧网关接收到的应答音和第一分类信号被发送到响应于该信号产生应答音的主叫侧网关。 可以将第二分类信号发送到主叫侧网关，其响应于第二信号调整应答音。

公开(公告)号：US06556622B1

公开(公告)日：2003-04-29

申请号：US09339353

申请日：1999-06-23

申请人： Keith T. Chu ,  Frank B. Hansen

发明人： Keith T. Chu ,  Frank B. Hansen

IPC分类号： H04B138

CPC分类号： H04L12/66 ,  H04L45/00

摘要： 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.

摘要翻译： 一种包括建立第一调制解调器和第二调制解调器之间的通信链路的第一调制解调器和第二调制解调器的通信系统。 通信链路具有第一组通信特性，包括至少数据被交换的第一通信信道或通信信道组，以及没有数据被交换的第二通信信道。 第一调制解调器或第二调制解调器被配置为经由第二通信信道以第一组通信特性发信号通知改变。

公开(公告)号：US06445734B1

公开(公告)日：2002-09-03

申请号：US09343873

申请日：1999-06-30

申请人： Li Chen ,  Farhad Aminian ,  Keith T. Chu

发明人： Li Chen ,  Farhad Aminian ,  Keith T. Chu

IPC分类号： H03H730

CPC分类号： H04L25/03038 ,  H04L2025/03707

摘要： Equalizer training is validated by techniques to detect false training. The validation techniques involve checking the unique time domain energy shaping of a plurality of taps of a trained equalizer of a modem for good training. The energy measure for each equalizer tap of the plurality of taps is approximated by summing the magnitude of a real component and a magnitude of an imaginary component of an equalizer coefficient corresponding to the equalizer tap. A tap with a highest approximate energy (i.e., the main tap) is then determined. Next, the main tap energy is compared to a main tap threshold and a predetermined guarding threshold. The plurality of taps are arranged in a time index ordered sequence. In determining the main tap threshold, a first energy sum of a beginning set of taps in the sequence is compared with a second energy sum of a last set of taps in the sequence. The lesser tap energy sum between the first energy sum and the second energy sum is the main tap threshold. The main tap is then compared with the main tap threshold and the predetermined guarding threshold. If the main tap is greater than the main tap threshold and the predetermined guarding threshold, then the train of the equalizer is good. If the main tap is less than the main tap threshold or the predetermined guarding threshold, then the train of the equalizer is false. The above-mentioned validation techniques are effective to recognize the unique time domain energy shaping characteristics of good-trained equalizer taps.

摘要翻译： 均衡器训练通过检测虚假训练的技术进行验证。 验证技术涉及检查用于良好训练的调制解调器的训练均衡器的多个抽头的独特时域能量整形。 通过对实际分量的大小和对应于均衡器抽头的均衡器系数的虚分量的幅度求和来近似多个抽头中的每个均衡器抽头的能量测量。 然后确定具有最高近似能量的抽头（即主抽头）。 接下来，将主抽头能量与主抽头阈值和预定保护阈值进行比较。 多个抽头以时间索引排序顺序排列。 在确定主抽头阈值时，将序列中开始的抽头集合的第一能量和与序列中最后一组抽头的第二能量和进行比较。 第一能量和和第二能量和之间较小的抽头能量之和是主抽头阈值。 然后将主抽头与主抽头阈值和预定保护阈值进行比较。 如果主抽头大于主抽头阈值和预定保护阈值，则均衡器的列是好的。 如果主抽头小于主抽头阈值或预定保护阈值，则均衡器的列是假的。 上述验证技术有效地识别训练有素的均衡器抽头的独特时域能量整形特性。