Interactive information services control system
    1.
    发明授权
    Interactive information services control system 失效
    互动信息服务控制系统

    公开(公告)号:US5481542A

    公开(公告)日:1996-01-02

    申请号:US149929

    申请日:1993-11-10

    摘要: A digital video, audio and data distribution system which enables a set-top terminal (STT) associated with a customer's television set or other information presentation device to request interactive digital video, audio and data services from a service provider (SP) through the use of control system messages transmitted via a hi-directional signalling path. The requested interactive service is transmitted from the service provider over a portion of the bandwidth of a broadband transmission network which is dedicated to interactive digital services. A Video Session Connection (VSC) is provided for setting up and maintaining interactive sessions between the set-top terminal and a video service provider during the time the interactive programming is provided to the customer. The set-top terminal and service provider establish the Video Session Connection via a two-way signalling path within the bandwidth of the transmission medium into the customer's home. Applications of the system of the invention include "movie on demand" services where the set-top terminal not only requests a movie to be transmitted from the service provider for immediate transmission, but also the bi-directional command channel permits the set-top terminal to control the video presentation by sending commands such as Play, Pause, Fast-Forward and the like to the Service Provider while the movie is being transmitted. Other applications of the invention include on-line data retrieval services, shop at home services and other services which require the use of an interactive connection.

    摘要翻译: 一种数字视频,音频和数据分发系统,其使与客户的电视机或其他信息呈现设备相关联的机顶终端(STT)能够通过使用从服务提供商(SP)请求交互式数字视频,音频和数据服务 经由高频信令路径发送的控制系统消息。 所请求的交互服务是通过专用于交互式数字服务的宽带传输网络的一部分带宽从业务提供商发送的。 提供视频会话连接(VSC),用于在向客户提供交互式节目编排时,在机顶终端和视频服务提供商之间设置和维护交互式会话。 机顶终端和服务提供商通过传输介质的带宽内的双向信令路径建立视频会话连接到客户的家中。 本发明的系统的应用包括“电影点播”服务,其中机顶终端不仅要求从服务提供商发送电影以供立即发送,而且双向命令信道允许机顶终端 通过在电影发送时向服务提供商发送诸如播放,暂停,快进等命令来控制视频呈现。 本发明的其他应用包括在线数据检索服务,家庭服务商店和需要使用交互式连接的其他服务。

    Videophone over cable networks
    2.
    发明授权
    Videophone over cable networks 有权
    通过电缆网络的视频电话

    公开(公告)号:US08458756B2

    公开(公告)日:2013-06-04

    申请号:US11567890

    申请日:2006-12-07

    IPC分类号: H04N7/173

    摘要: The present invention is directed to a videophone system implemented over a cable television network. The instant invention provides a videophone comprising a camera for capturing images associated with a videophone signal, a videophone unit and a set top terminal or cable modem connecting the videophone to a cable television network. Videophone signals created at the call origination site are encoded and transported to a predetermined destination over an existing cable television network. The system uses IP addresses as phone number on the network. Additionally, transport of videophone signals between different cable systems is accomplished via a high-speed long distance data network, such as, for example, a satellite network, that provides communication between the headends of the different cable television systems. The set top terminal may be a conventional subscriber terminal, a cable modem or a subscriber terminal configured to operate as a cable modem. The set top terminal provides the interface between the videophone and the cable television system. More than one videophone may be connected to a single set top terminal. Display of videophone data may be achieved using any conventional display device, including a television set or a personal computer monitor. Accordingly, the videophone system described herein takes advantage of increased bandwidth and lower cost realized by using existing cable television infrastructure and technology.

    摘要翻译: 本发明涉及一种通过有线电视网络实现的可视电话系统。 本发明提供了一种可视电话,其包括用于捕获与可视电话信号相关联的图像的相机,可视电话单元以及将可视电话连接到有线电视网络的机顶终端或电缆调制解调器。 在呼叫发起站点创建的视频电话信号被编码并通过现有的有线电视网络传输到预定的目的地。 系统使用IP地址作为网络上的电话号码。 另外,在不同的有线电视系统之间传输视频电话信号是通过提供不同有线电视系统的头端之间的通信的高速长距离数据网络,例如卫星网络实现的。 机顶终端可以是被配置为作为电缆调制解调器工作的常规用户终端,电缆调制解调器或用户终端。 机顶终端提供可视电话和有线电视系统之间的接口。 多个可视电话可以连接到单个机顶终端。 可以使用包括电视机或个人计算机监视器的任何常规显示设备来实现可视电话数据的显示。 因此,本文描述的可视电话系统利用通过使用现有的有线电视基础设施和技术实现的增加的带宽和更低的成本。

    Method and apparatus for minimizing error propagation in correlative
digital and communication system
    5.
    发明授权
    Method and apparatus for minimizing error propagation in correlative digital and communication system 失效
    用于最小化相关数字和通信系统中的误差传播的方法和装置

    公开(公告)号:US5287351A

    公开(公告)日:1994-02-15

    申请号:US851588

    申请日:1992-03-16

    摘要: A digital audio communication system includes a digital modulation and demodulation scheme which efficiently uses the bandwidth and channel spacing of a cable television system. A 30 channel digital bit stream is demultiplexed into six groups of five channels. Each group of channels thereafter modulates a carrier by a quadrature partial response (QPR) process. The QPR signal, an amplitude modulated, double sideband, carrier suppressed (AM DSBSC) signal, is then transmitted over the cable system to a multiplicity of subscribers, each of which has a QPR demodulator. The demodulators are of the decision feedback type having a modified Costas loop carrier recovery circuit. The grouping of an odd number (five) of digital audio channels per QPR modulator minimizes error propagation due to the correlative QPR demodulation process. The decision feedback decoding is implemented in simple current nodes where a bilevel output from the decoded data is subtracted from a tertiary level output of a mixer. The resulting bilevel current is converted to a voltage, filtered, and limited to produce a logic output level. The modified Costas loop provides an error voltage based upon the difference of the received data states versus the nominal data states and the quadrant the data occupies. The error voltage is generated by differencing the outputs of two analog switches which have as their inputs analog signals representative of the amplitude level of the data and its inverse of one phase. The sign of the data bit of the opposite phase is used to control the switch and thus select which signal is used.

    摘要翻译: 数字音频通信系统包括有效地使用有线电视系统的带宽和信道间隔的数字调制和解调方案。 30通道数字比特流被解复用为六组五个通道。 此后,每组信道通过正交部分响应(QPR)处理来调制载波。 然后,通过电缆系统将QPR信号(幅度调制的,双边带,载波抑制(AM DSBSC))传输到多个用户,每个用户具有QPR解调器。 解调器具有具有经修改的科斯塔斯环路载波恢复电路的判决反馈类型。 每个QPR调制解调器的奇数(5)个数字音频信道的分组使由于相关QPR解调过程引起的误差传播最小化。 决策反馈解码在简单的电流节点中实现,其中来自解码数据的双向输出从混频器的第三级输出中减去。 所得到的双电平电流被转换成电压,被滤波并被限制以产生逻辑输出电平。 经修改的科斯塔斯循环基于接收的数据状态与标称数据状态和数据占用的象限的差异提供误差电压。 误差电压通过差分两个模拟开关的输出产生,这两个模拟开关的输入具有代表数据幅度电平的模拟信号及其一相的反相。 反相的数据位的符号用于控制开关,从而选择使用哪个信号。