Abstract: An Off-premises CATV system having an interdiction apparatus includes a remote microprocessor which receives commands and data from the headend over the cable distribution plant. The data is in a modified Manchester format (biphase-M) at 19.2 K baud which is then frequency modulated on a carrier of 108.2 MHz. A receiver detects the base band signal and outputs a serial digital signal to one input port pin of the microprocessor. The microprocessor rejects incorrect messages by measuring the duration between the negative transitions in the data signal. For those negative transitions which do not fall within predetermined windows where data transitions or a start of message character should be, an error is detected and the message is discarded.

Abstract: A subscriber terminal apparatus for a television in an in-band subscription television system is provided. The subscriber terminal is adapted to receive a television signal including video, audio, and data information. A tuner of the subscriber terminal tunes channels of the television signal and an on-screen display control circuit selectively provides a display of characters on the television. A tuner control tunes the tuner to a channel having in-band data when the display of characters is provided on the television.

Abstract: An off premises CATV system is disclosed. A headend transmits programming including pay-per-view programming and a cable distribution system distributes the programming. An off premises unit is coupled to the cable distribution system for supplying the programming to at least one subscriber. A subscriber terminal is coupled to the off premises unit over a communication link. The subscriber terminal including an input device for inputting subscriber-supplied signals indicative of a pay-per-view event to generate a message. A transmitter responsive to the subscriber-supplied signals transmits the message to the off premises unit over the communication link. The message is transmitted at a plurality of random times within a predetermined period of time.

Abstract: A diagnostic method and apparatus for a cable television interdiction system is provided. One or more diagnostic modes each corresponding to a particular problem or state associated with the interdiction unit may be entered into by the interdiction unit. If a diagnostic mode is detected, the television signal provided to a television signal receiving apparatus, e.g., a television set, is disabled for a specified length of time. Thereafter, depending upon the diagnostic mode detected, either the television signal provided to the receiving apparatus and/or a light-emitting device, e.g., a light-emitting diode (LED), is pulsed a specified number of times corresponding to the detected diagnostic mode. The cycle of disabling the television signal provided to the receiving apparatus and pulsing either or both the television signal provided to the receiving apparatus and/or the LED is repeated until a transaction is received from the headend cancelling the diagnostic mode.

Abstract: Apparatus for broadband signal distribution is equipped with a detector for detecting when the apparatus is open and is further adapted to receive an entry code generator. If the entry code generator is not installed or, if installed, fails to generate an entry code which matches an authorized entry code stored in the apparatus, the apparatus enters a particular mode of operation whereby service provided by the apparatus is interfered with. The entry code generator comprises a circuit board for coupling with an electrical connector of the apparatus having at least one ear which precludes closure of a cover to the apparatus. A method of screening access to the apparatus from others than authorized service personnel includes waiting a predetermined period of time for coupling the access code generator before service is interfered with. Furthermore, the stored access code may be changed or the predetermined time varied by addressable command from a headend of a broadband signal distribution system.

Abstract: A fiber optics communications system and method are provided. The system includes a transmitter apparatus located at a first location and having a plurality of laser transmitters and a plurality of optical switches coupling optical signals from the laser transmitters to optical fibers. A receiver apparatus is located at a second location remote from the first location and includes a plurality of receivers and a plurality of optical switches coupling optical signals from the optical fibers to the optical receivers. A first control circuit controls the switches of the transmitter apparatus in accordance with conditions at the first and the second locations. A second control circuit controls the switches of the receiver apparatus in accordance with conditions at the first and second locations. The backing up of a plurality of transmitting lasers by a single back up laser and the backing up of a plurality of receivers by a single back up receiver are also described.

Abstract: A receiver is described for optical signals which are amplitude modulated with broadband radio frequency signals. The receiver includes an optical detector which receives the incoming optical signal and generates a radio frequency electrical signal which varies with the power level of the incoming optical signal. This electrical signal is applied to a pair of amplifiers which are connected in a push-pull relationship. In a preferred embodiment, a tuning network is connected between the two amplifiers for optimizing the amplification of a selected band of radio frequencies.

Abstract: An apparatus and method is described for transmitting, receiving and communicating program data signals which are combined with digital data signals. Preferably, the present invention compresses 30 digital audio signals, multiplexes them with title, track, artist, record label, year, etc., program information, and transmits the combined signals via satellite to a receiving station. The receiving station demultiplexes the signals and sends them via a cable distribution system to a subscriber's digital music tuner. This tuner further demultiplexes and decodes the signals so that the digital audio signals may be converted to analog and output for listening, while the corresponding data signals are communicated to the subscriber. In an alternative preferred embodiment, the program data signals are transmitted to a remote control receiver where they are displayed. The system described in the present invention may be used for transmitting video, software or games with program data to subscribers.

Abstract: A method of transferring a data message from a remote unit to a central location is provided. A plurality of data channels is selected for transmitting the data message from the remote unit to the central location. At least one random transmit time is generated for transmitting the data message for each of the plurality of data channels. The data message is transmitted over the plurality of data channels at the transmit times. An apparatus for transferring a data message from a remote unit to a central location is also provided.

Abstract: A off-premises CATV system includes a compensation control including a picture carrier controlled automatic gain control and an automatic slope control. A broadband television signal output from a variable gain device is distributed by a radio frequency signal splitter to a number of subscribers for interdiction by the generation of a number of jamming signals. The variable gain device and a variable impedance device which is frequency dependent are connected in series for automatic gain control and automatic slope control, respectively. A first feedback control is used to compare a first portion of the broadband television signal to a reference power level and to control the variable gain device to null the error. A second feedback control is used to compare a second portion of the broadband signal to a second reference power level and to control the variable impedance device to null the error.

Abstract: A method for automatically selecting optimum frequencies for transmitting data from remote terminals upstream to a system manager is provided. The system manager initially selects a set of frequencies from a larger set of available frequencies and transmits a command downstream to each remote terminal indicating which frequencies to use. Each remote terminal transmits data messsages on each selected frequency in response to addressed commands generated by the system manager. The system manager receives and counts the data messages on each of the frequencies, and after a statistically significant number of messages are received, removes from use the frequency with the lowest number of data messages received. This frequency is replaced with either (1) a previously untried frequency, or if all frequencies have been tried, (2) a previously tried frequency with the highest number of data messages received.

Abstract: A fiber optic cable connector secures a fiber optic cable to an equipment housing (e.g., a CATV equipment housing) and allow individual fibers of the cable to pass into the housing in a strain relieved condition for connection to electro-optical componentry. A strength component of the fiber optic cable is clamped within the connector body, exterior of the equipment housing, to strain-relieve the optical fibers from forces imparted to the cable, without taking up housing space. Also, the connector clamps a strength component of a protective "fan-out" tube covering the individual fibers of the cable passing from the connector into the housing, to strain-relieve the fibers from forces imparted to the fan-out tube. The clamping action is effected by progressive threaded engagement of two connector bodies.

Abstract: 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.

Abstract: An off-premises i.e. a negative or positive trap, jamming cable television or interdiction system, includes a picture carried controlled automatic gain control circuit. A broadband television signal output of a variable gain device is distributed by a radio frequency signal splitter to a number of subscribers. A portion of the output of the variable gain device comprising at least two contiguous television channels is passed to a power level detector. A detected power level is compared with a predetermined power level reference for adjusting the gain of the variable gain device. The predetermined power level reference is set to equal the attenuation between the off-premises equipment and the subscriber premises plus the desired level at the entrance to the subscriber's premises. The power level of a jamming or interdicting signal for denying access to unauthorized television programs is set to fall within a predetermined range of power levels related to the predetermined power level reference.

Abstract: In order to facilitate the installation of off-premises equipment which distributes CATV signals from a distribution cable to subscribers and to allow different subscribers to receive different classes of service (basic service alone or with one or more premium or pay-per-view channels), a pair of housings are used, one containing circuits for tapping the signals from the cable and the other for electronics hardware which processes the signals and distributes them to subscribers in accordance with the class of service which is ordered by the subscribers. The housing containing the tapping circuits is permanently connected to the cable and need not be removed or replaced when connecting additional subscribers or changing the class of service. The housing containing the electronics hardware for processing the signals may be attached to or along side of the first housing. The first housing may be suspended from the strand which supports the cable in an aerial mount configuration.

Abstract: An optical communications system including a plurality of modulated radio frequency carriers which span more than an octave in bandwidth. In one implementation, the carriers are grouped into ranges which span less than octave in bandwidth and separately transmitted over uique optical links. In another implementation, the groups are multiplexed on one optical link by using different wavelengths. In still another implementation, several of the bands are up-converted to the highest band of interest and then transmitted, either over single or multiple links. The resulting signals are demodulated and then down-converted before they are recombined into the broadband signal in excess of an octave in bandwidth.

Abstract: A dynamic global callback technique which is capable of maintaining a manageable number of incoming calls to a central location from a plurality of remote units. A plurality of remote units are prompted to initiate callback attempts to a central location during a given callback period. The number of successful callback attempts from the remote units to the central location is monitored. The callback period if dynamically adjusted so as to cause the monitored number of successful callback attempts to approximately equal the number of successful callback attempts capable of being handled by the central location without overloading the telephone network.

Abstract: Automatic level calibration apparatus for transmitting data from a cable television terminal to the headend of a cable television system comprises programmable transmitter apparatus of the terminal, programmable receiving apparatus at the headend and a calibration controller. Responsive to an addressed command from the headend, the programmable transmitter apparatus returns a sequence of levels at a particular calibration frequency. The programmable receiver apparatus determines an indication of the received signal strength of each of the levels of the sequence of levels. The controller determines an optimum level for transmissions from the terminal.

Abstract: Light wave communication over optical fiber networks for the distribution of broadband, multiple channel CATV (Cable Televison) signals uses fibers which carry amplitude modulated broadband signals over a considerable distance (6-30 km) to a fiber node. Electrical to optical transmitters at the head end and optical to electrical receivers at the fiber node launch and receive the optical signals corresponding to the broadband CATV electrical signals. Distribution from the fiber node to subscribers is obtained by transmitting the electrical signals from the receivers at the node through a limited cascade of amplifiers along an electrical transmission line (coax cable). The limited cascade is much shorter than the fiber span and includes trunk amplifiers which are insufficient in number to add significant losses or distortion. Line extender amplifiers may be connected to output couplers located off the subscribers premises and then via electrical cables to the subscribers.

Abstract: An optical fiber retention device which is adapted to positively locate and retain one or more optical fibers while providing strain-relief. The optical fiber retention device includes a pair of resilient strip members which snap fit together to positively restrain the optical fibers between them. The strip members include a base strip having one or more generally U-shaped channels which support individual optical fibers in a common plane. The other strip member comprises a top member which includes two resilient keys which snap fit into resilient keyways in the base member. The top member has an elongated generally rectangular surface which retains the optical fibers in the channels for strain relief. The base member additionally includes a pair of resilient keys which snap fit into the keyways of other base members to allow the base member to be stacked on one another for tiers or racks of support channels and to allow mounting on a plate of a termination or branch box.