Abstract: A method, system and apparatus for frequency sweeping and frequency sweep testing a CATV system wherein the CATV system has a plurality of channels and is transmitting television signals over at least some of the channels. The system includes a head end test unit coupled to the CATV system at its head end and a remote test unit coupled to the CATV system at a location remote from the head end. The head end test unit sweeps the CATV system by either generating and transmitting test signals at the channel frequencies over the CATV system or, if a television signal is being transmitted on a channel, using the television signal as the test signal. The head end test also measures the signal levels of the test signals and at the end of the sweep, transmits telemetry signals, which include the frequencies to be swept and the measured signal levels, over the CATV system to the remote test unit using the same transmitter that it used to generate and transmit the test signals.

Abstract: A video sync slicing circuit is disclosed that employs an adjustable gain control (AGC) amplifier and circuitry that adjusts a gain of the AGC amplifier such that a blanking level of the video signal at an output of the AGC amplifier equals a blanking reference voltage. The slicing circuit includes a circuit that triggers a composite sync signal when a sync pulse of the video signal equals the fifty percent slicing level.

Abstract: The present invention is a method and apparatus for integrating a personal communication system with a cable television plant. A set of radio antenna devices (RAD) are connected to the cable plant. The RADs provide frequency conversion and power control of signal received from the cable plant for wireless transmission to the remote units. The RADs also provide power control and frequency conversion of wireless signals received from the remote units for transmission by the RADs onto the cable plant. In addition to the functions of standard base stations and centralized controller, the CATV base station must also compensate for gain variations in the cable plant. The downstream power control is regulated by a RAD reference signal which can be hidden within the CDMA signal for maximum efficiency. The upstream power control is regulated by an upstream gain reference signal which is individually transmitted by each RAD on the upstream link.

Abstract: A bi-directional cable network having a hybrid return gate system that prevents undesirable energy in the bi-directional cable network's return path from adversely effecting the entire network whether the network is operating as a contention based network, a reservation based network, or combination of contention and reservation. The hybrid return gate system comprises a solid state radio frequency switch used to connect and disconnect the return path of a bi-directional communication path in conjunction with a transmission from one of a plurality of remote points. Transmissions from a remote point occur in one of a plurality of dynamically defined contention time slots or reservation time slots. At least one network monitoring time slot can also defined to monitor and/or test the bi-directional cable network. In one embodiment each return gate services a plurality of remote points downstream from the return gate. In a second embodiment each remote point has a dedicated return gate.

Abstract: A signal processing unit is provided with one or more analyzing units to analyze textual information decoded from a number of channels of a communication signal to determine if channel contents of the channels are among channel contents defined by selection data. The signal processing unit is further provided with an arbitrating unit for arbitrating display and/or recording resource contentions among channels having channel contents defined by the selection data. The signal processing unit is suitable for incorporation in a stand-alone as well as a client computer system.

Abstract: Noise is reduced and bandwidth may be increased in a CATV transmission system by modulating a portion of subscriber-generated upstream signals to a high frequency band (e.g., 750-100 MHz) and then digitally regenerating such signals. To further reduce noise, the digitally regenerated upstream signals are transmitted by in a baseband digital format to the head end (120) via a digital E/O converter (330). Increased downstream bandwidth is obtained by modulating a portion of the downstream signals to a higher frequency band (e.g., 500-750 MHz) and then digitally regenerating such signals.

Abstract: A system of sending digital high definition television pictures and sound in a limited bandwidth using the principle of analyzing and sending changes in pictures and coded instructions rather than entire pictures. Delaying the presentation of the pictures slightly permits major picture changes and sound to be sent at a lower bit rate over a longer period of time. Non-changing areas of the pictures are sent to the receiver and remain on the screen until changes occur or refresh is desired. When TV cameras shift orientation, backgrounds of pictures or objects which do not change are shifted on the receiver with appropriate codes rather than repeating the entire picture. Fast changing portions of pictures are determined and sent more frequently than slower or non-changing ones. Sound information is acquired and compared to libraries of sound fragments.

Abstract: A symbol timing recovery circuit and method of a digital television is disclosed including: an analog-to-digital converter (10) for sampling a received analog signal by a symbol clock to be converted to digital data; demodulator (20) for recovering a carrier wave, demodulating the digital data to a baseband signal and generating a segment signal; a segment synchronizing signal detector (40) for detecting a segment synchronizing signal from the segment signal; a phase error detector (50) activated by the segment synchronizing signal, for receiving the segment signal and detecting a phase error of synchronizing symbols of the segment synchronizing signal; and a symbol clock is phase adjuster (60) for adjusting the phase of the symbol clock according to the phase error of the synchronizing symbols to be supplied to the analog-to-digital converter as the symbol clock.

Abstract: An architecture for providing interactive broadband products and services uses existing cable and telephone plant. The architecture includes a central office switch in communication with a head-end server and a Customer Premises Equipment (CPE) device such as, for example, a modem emulator, data terminal, set-top terminal or personal computer. The CPE device is provided in communication with the head-end server via cable plant for downstream broadcasts and is further provided in communication with a central office switch via telephone plant for upstream signaling and downstream control messages.

Abstract: When the margin between a write frequency-divided clock signal and a read frequency-divided clock signal becomes remarkably decreased, a clock phase difference detecting circuit outputs a reset execution command. While a reset execution command is being output in a blanking interval, a reset signal generating circuit supplies a reset signal to an input side counter corresponding to a reset execution command so as to reset the phase of the write frequency-divided clock signal to an initial state.

Abstract: A post-processor for a decoded video sequence includes a digital noise reduction unit and an artifact reduction unit which significantly reduce blocking artifacts and mosquito noise in a video image. The post-processor uses both temporal and edge characteristics of the video image to enhance the displayed image. The post-processor operates on a current frame of pixel data using information from the immediately preceding post-processed frame that is stored in a frame memory of the post-processor. The post-processor first identifies texture and fine detail areas in the image. The post-processor uses artifact reduction only on portions of the image that are not part of an edge, and are not part of a texture or fine detail area. Since artifact reduction is not utilized on these areas, the post-processed image is not softened in regions where it is easily noticed by the human eye.

Abstract: A method and apparatus allows an information provider to broadcast a graphical interactive information system application to a user even using a low-bandwidth transport such as the VBI. A compact protocol encapsulates graphical information using definitions of graphical objects and resources. A scripting and command language is also highly compact. A reception component receives the compact protocol and displays and operates a complete graphical interactive information system application.

Abstract: A vertical sync separator circuit that operates with signals that have different arrangements of horizontal equalizing pulses in the vertical interval. The composite signal is integrated and used to operate a Schmidt trigger/inverter that feeds the data input of a D flip/flop. The flip/flop is clocked by the horizontal equalizing pulse that occurs after the beginning of the vertical pulse. In an arrangement that operates without equalizing pulses, a second trigger circuit is operates from a less than one-half line delay and supplies the reset input of the flip/flop. The arrangement provides consistent development of the vertical sync output pulse.

Abstract: MPEG compression for video/audio data is completed in real- or better than real-time by using computer processors in thousands of television receiver set-top boxes interconnected to a cable television network. The set-top boxes form a massively parallel, distributed computer network. MPEG compression for video/audio services is completed by partitioning the processing of video/audio frames into subtasks, and distributing these subtasks to set-top boxes which are not being used for subscriber services. After compression, the compressed video/audio frames are collected from the set-top boxes and are reconstructed into a compressed video/audio stream in the proper temporal order.

Abstract: Ingress noise in a hybrid fiber-coax transmission system (10) may be reduced by employing asymmetric taps (30.sub.1 '-30.sub.8 ',) between a pair of line extenders (28--28) for attenuating downstream and upstream information by different weights. The downstream weights of the taps are selected to achieve a substantial constant power level at each tap for individual subscribers (14--14). The upstream attenuation of each tap is selected to allow for a nearly constant level of subscriber-generated information to be received at the line extender while the subscriber generated upstream information is supplied to the taps at a constant value that is maximized to reduce the effect of ingress noise.

Abstract: The customer premise equipment of the invention consists of an OC-1, OC-3C or OC-12C receiver and an OC-1, OC-3C or OC-12C transmitter that interface with an ATM segmentation/reassembly circuit. In the downstream direction the segmentation/reassembly circuit receives the signals from the receiver and separates the signals into ATM cells. In the upstream direction the segmentation/reassembly circuit reassembles the ATM cells from the customer premise into a broadband signal and delivers the signal to the transmitter. The segmentation/reassembly circuit interfaces with a passive bus to deliver to and receive cells from a video decoder, POTS line card and a personal computer interface such that the customer can receive voice, data and video on a fiber to the home access architecture. A video system provides an ensemble of video channels at the customer premise.

Abstract: The present invention is a method and apparatus for integrating a personal communication system with a cable television plant. A set of radio antenna devices (RAD) are connected to the cable plant. The RADs provide frequency conversion and power control of signal received from the cable plant for wireless transmission to the remote units. The RADs also provide power control and frequency conversion of wireless signals received from the remote units for transmission by the RADs onto the cable plant. In addition to the functions of standard base stations and centralized controller, the CATV base station must also compensate for gain variations in the cable plant. The downstream power control is regulated by a RAD reference signal which can be hidden within the CDMA signal for maximum efficiency. The upstream power control is regulated by an upstream gain reference signal which is individually transmitted by each RAD on the upstream link.

Abstract: A data readout time adjuster to be used for a video-on-demand system includes the following units. A readout time adjusting data storage unit stores image data for adjusting readout time to be provided to subscribers who have not been assigned the readout right and are waiting for a start of a readout operation. The image data for adjusting readout time cause no inconvenience even if a transmission of the image data is interrupted any time. A readout start position check unit checks an expected time of an occurrence of the readout right and a readout start position at the expected time in response to an additional data transmission request.

Abstract: An analog to digital converter circuit having sync control is constructed to monitor the sync condition of the digital output. When sync is lost, for example due to a low input signal level or due to an out of phase situation, the gain of the output increased to relatively high level so as to enhance the possibility of detecting the sync condition. As soon as sync is reestablished the gain is immediately turned down to a level lower than the blanking level and then gradually increased to the blanking level. The gain levels at startup and during the sync reestablishment intervals are fixed but under selective control.

Abstract: A system is provided that enhances the interactivity of multimedia information in a closed cable network such as a hotel system or the like. The system includes a multimedia processing plurality of multimedia processing system, a telephone switching system, a video control system, a service operations platform, and a plurality of interactive devices. This system has the advantage of providing compression and/or transmission algorithms to maximize enhancement of the multimedia information. The system also allows for sending facsimiles and voice mail messages on the closed cable system. The system allows for enhanced interactivity within a closed cable system with minimum modification to the existing network.