Abstract: A coaxial cable tap comprises a housing, and a faceplate coupled to the housing. The faceplate comprises a first directional tap port, and a diagnostic reverse (DR) port configured to receive a first upstream signal originating downstream from the coaxial cable tap, and inject a downstream test signal in a downstream direction. A hybrid fiber-coaxial (HFC) network comprises a headend, a first amplifier coupled to the headend, and a tap coupled to the first amplifier, configured to couple to a plurality of cable modems (CMs), and comprising a diagnostic forward (DF) port configured to receive a downstream signal originating from the first amplifier, and inject an upstream test signal in an upstream direction for reception at the headend.

Abstract: A coaxial cable remote diagnostic management tool (RDMT) comprises a receiver configured to receive a first signal, wherein the first signal is a time domain signal; and receive an instruction to analyze the first signal; and a processor coupled to the receiver and configured to: generate a trigger based on the instruction; convert the first signal into a second signal, wherein the second signal is a frequency domain signal; perform a comparison of the trigger to the second signal; and process the second signal based on the comparison.

Abstract: A coaxial cable tap comprises a housing, and a faceplate coupled to the housing. The faceplate comprises a first directional tap port, and a diagnostic reverse (DR) port configured to receive a first upstream signal originating downstream from the coaxial cable tap, and inject a downstream test signal in a downstream direction. A hybrid fiber-coaxial (HFC) network comprises a headend, a first amplifier coupled to the headend, and a tap coupled to the first amplifier, configured to couple to a plurality of cable modems (CMs), and comprising a diagnostic forward (DF) port configured to receive a downstream signal originating from the first amplifier, and inject an upstream test signal in an upstream direction for reception at the headend.

Abstract: A communication system comprising three communication resources: a contention-type access block, a non-contention access block and a second non-contention access block called a reserved block. Each time that a remote unit has a block of data to transfer to a hub station, it sends the block of data over the contention-type access block. It also sends a corresponding notification message over the reserved block. If the hub station receives the notification message but not the block of data, it sends a response message to the remote unit which designates a resource within the non-contention access block. The remote unit then sends the block of data to the hub station over the designated resource.

Abstract: In a system in which multiple remote units compete for limited communication resources, a remote unit accesses the system by randomly selecting a first sequence from a set of predetermined sequences. The remote unit transmits a data bit stream modulated with the first sequence beginning at one of a set of recurring admission boundaries. If the remote unit determines that the data bit stream has not been successfully received at a hub station, it randomly selects a second sequence from the set of predetermined sequences. The remote unit transmits the data bit stream modulated with the second sequence beginning at one of the set of recurring admission boundaries.

Abstract: A communication system comprising three communication resources: a contention-type access block, a non-contention access block and a second non-contention access block called a reserved block. Each time that a remote unit has a block of data to transfer to a hub station, it sends the block of data over the contention-type access block. It also sends a corresponding notification message over the reserved block. If the hub station receives the notification message but not the block of data, it sends a response message to the remote unit which designates a resource within the non-contention access block. The remote unit then sends the block of data to the hub station over the designated resource.

Abstract: A communication system extracts a received modulation frequency from baseband modulation. This frequency is used as a reference to control the output of a variable oscillator. The output of the variable oscillator may be used to generate a transmit upconversion frequency, and may also be used to perform a downconversion from IF to baseband during receive operations.

Abstract: A communication system extracts a received modulation frequency from baseband modulation. This frequency is used as a reference to control the output of a variable oscillator. The output of the variable oscillator may be used to generate a transmit upconversion frequency, and may also be used to perform a downconversion from IF to baseband during receive operations.

Abstract: Time alignment of a signal from a remote unit at a hub station of a multiple access system is achieved based upon an initial time indication received from the hub station at the remote unit via a satellite. The remote unit transmits a signal to the satellite, monitors for a retransmission of the signal from the satellite and measures the time difference between the outgoing and incoming signals. The remote unit, then, uses the time difference to more finely adjust the time alignment. Alternatively, the remote unit transmits a first signal advanced with respect to an on-time estimate to the hub station and receives a responsive energy indication from the hub station. The remote unit transmits a second signal delayed with respect to the on-time estimate to the hub station and receives a responsive energy indication from the hub station. The remote unit compares the two energy indications and adjusts the on-time estimate.

Abstract: Transmission of TCP/IP data over a satellite link from a hub station to a plurality of remote units. The data, transmitted over the satellite link, uses the digital video broadcast (DVB) protocol. A field in the DVB header is used to indicate the location of the start of a new TCP/IP data packet within the DVB data. Use of a field in the DVB header to indicate the location of the start of a new TCP/IP data packet supports variable location of TCP/IP data within a DVB frame, and therefore more efficient use of the DVB bandwidth.

Abstract: Transmission of TCP/IP data over a satellite link from a hub station to a plurality of remote units. The data, transmitted over the satellite link, uses the digital video broadcast (DVB) protocol. A field in the DVB header is used to indicate the location of the start of a new TCP/IP data packet within the DVB data. Use of a field in the DVB header to indicate the location of the start of a new TCP/IP data packet supports variable location of TCP/IP data within a DVB frame, and therefore more efficient use of the DVB bandwidth.

Abstract: Transmission of TCP/IP data over a satellite link from a hub station to a plurality of remote units. The data, transmitted over the satellite link, uses the digital video broadcast (DVB) protocol. A field in the DVB header is used to indicate the location of the start of a new TCP/IP data packet within the DVB data. Use of a field in the DVB header to indicate the location of the start of a new TCP/IP data packet supports variable location of TCP/IP data within a DVB frame, and therefore more efficient use of the DVB bandwidth.

Abstract: In a system in which multiple remote units compete for limited communication resources, a remote unit accesses the system by randomly selecting a first sequence from a set of predetermined sequences. The remote unit transmits a data bit stream modulated with the first sequence beginning at one of a set of recurring admission boundaries. If the remote unit determines that the data bit stream has not been successfully received at a hub station, it randomly selects a second sequence from the set of predetermined sequences. The remote unit transmits the data bit stream modulated with the second sequence beginning at one of the set of recurring admission boundaries.

Abstract: In a system in which multiple remote units compete for limited communication resources, a remote unit accesses the system by randomly selecting a first sequence from a set of predetermined sequences. The remote unit transmits a data bit stream modulated with the first sequence beginning at one of a set of recurring admission boundaries. If the remote unit determines that the data bit stream has not been successfully received at a hub station, it randomly selects a second sequence from the set of predetermined sequences. The remote unit transmits the data bit stream modulated with the second sequence beginning at one of the set of recurring admission boundaries.

Abstract: When an installed wireless remote unit is operating in the field, routine operation is interrupted to enter a calibration mode. In calibration mode, the compression point of a circuit element is determined by applying a series of different drive levels to the circuit element. Based upon the determination of the compression point, a maximum transmission point is selected for the remote unit. Upon resumption of normal operation, the remote unit uses the maximum transmission point to limit the signal power level transmitted over the wireless link. As time passes or operating conditions change, the calibration process is re-executed.

Abstract: When an installed wireless remote unit is operating in the field, routine operation is interrupted to enter a calibration mode. In calibration mode, the compression point of a circuit element is determined by applying a series of different drive levels to the circuit element. Based upon the determination of the compression point, a maximum transmission point is selected for the remote unit. Upon resumption of normal operation, the remote unit uses the maximum transmission point to limit the signal power level transmitted over the wireless link. As time passes or operating conditions change, the calibration process is re-executed.

Abstract: A phase accumulator for accumulating digital frequency words, which, as accumulated, represent the phase of a cyclic waveform of a predetermined frequency. The phase accumulator includes a coarse-component accumulator for accumulating coarse phase components of the digital frequency words; a fine-component accumulator for accumulating fine phase components of the digital frequency words; and means for incrementing the coarse-component accumulator in response to accumulation of the fine phase components.

Abstract: A system for companding digital audio signal samples processes the digital audio signal samples to correct errors induced by the compression and expansion processes. These errors are calculated prior to compressing the samples. Such errors are calculated in accordance with a predetermined compression process and a predetermined expansion process; and the digital audio signal samples are corrected in accordance with such calculations prior to compression. The compression process includes providing a 3-bit gain word for a block of 70 samples. The gain word is computed in accordance with the position of the most significant "1" bit in the sample(s) having the peak magnitude. Each individual sample is processed in accordance with the block gain word to compress the sample by reducing the number of magnitude bits.

Abstract: A system for reproducing in a descrambler of a subscriber communication network a subscriber key signal that is unique to the descrambler and was used in encrypting a key signal that must be decrypted for use in descrambling a signal received by the descrambler. The scrambled signal is received by the descrambler together with the encrypted key signal and a key generation number containing an address for accessing a predetermined area in a memory contained in the descrambler.

Abstract: A system and method for scrambling and selectively descrambling television signals that are transmitted to subscribers' descramblers in a subscription television system. A working key signal is generated by processing an "initialization vector" signal in accordance with the DES algorithm upon the algorithm being keyed by either a common category key signal or some other key signal. A unique encryption keystream is generated by processing the initialization vector signal in accordance with the DES algorithm upon the algorithm being keyed by the working key signal. A television signal is scrambled in accordance with the unique encryption keystream to provide a scrambled television signal.