Abstract: A system for electric power demand monitoring and control includes one or more data distribution networks interconnecting network interfaces or intelligent utility units located at customer sites with a host computer located in the utility company offices. A network within the site interconnects each intelligent utility unit or network interface with power consuming units for providing data on power usage and power control. A data distribution network interconnects the plurality of intelligent utility units or network interfaces to the host computer as a head end unit, the data distribution network providing downstream communication channels from the host computer to the plurality of intelligent utility units and network interfaces, and upstream communication channels from the plurality of intelligent utility units and network interfaces to the host computer. The communication channels are organized as frequency division multiplex channels in a frequency spectrum.

Abstract: A system for electric power demand monitoring and control includes one or more data distribution networks interconnecting intelligent utility units located at customer homes with a host computer located in the utility company offices. Each intelligent utility unit is associated with a customer home for connecting and disconnecting a power service meter, monitoring customer demand, and controlling power to selected units. A network within the home interconnects each intelligent utility unit with power consuming units for providing data on power usage and power control. A data distribution network interconnects the plurality of intelligent utility units to the host computer as a head end unit, the data distribution network providing downstream communication channels from the host computer to the plurality of intelligent utility units and upstream communication channels from the plurality of intelligent utility units to the host computer.

Abstract: A system for electric power demand monitoring and control includes one or more data distribution networks interconnecting intelligent utility units located at customer homes with a host computer located in the utility company offices. Each intelligent utility unit is associated with a customer home for connecting and disconnecting a power service meter, monitoring customer demand, and controlling power to selected units. A network within the home interconnects each intelligent utility unit with power consuming units for providing data on power usage and power control. A data distribution network interconnects the plurality of intelligent utility units to the host computer as a head end unit, the data distribution network providing downstream communication channels from the host computer to the plurality of intelligent utility units and upstream communication channels from the plurality of intelligent utility units to the host computer.

Abstract: A distributed intelligence network using time and frequency domain multiplexing. On power-up, each node determines its skew and requests downloading of program code and configuration data. A node claims timeslots by transmitting a packet into an apparently empty timeslot and verifying receipt of its own packet.

Abstract: A telecommunication bridge system uses synchronized arbitration in a portion of a frame of a Radio Frequency (RF) subsystem and is transparent to Ethernet layer protocols and Ethernet-type packets in order to increase bandwidth utilization and effectively extend Ethernet networks to metropolitan-area-wide application. The telecommunication bridge system comprises an enhanced Ethernet network interface subsystem coupled to a conventional Ethernet medium and a control subsystem including an RF modem, in turn coupled to a frame synchronized RF medium in a metropolitan-sized network. On one side the control subsystem emulates all Ethernet layer protocols and on the other side conducts a prioritized arbitration scheme during only a portion of a time division multiplexed frame, the remainder of the frame for carrying a payload of unmodified packets to other bridges.

Abstract: An apparatus and method for extending the range of a digital data network by enhancing skew control. The apparatus is a circuit for use in a network interface unit. The apparatus measures the distance of the network interface unit from the head-end retransmission unit of the network by transmitting a series of signal packets on the network and counting the time it takes for the packets to be received back at the interface unit. All transmissions on the network take place with reference to a timing mark transmitted by the head-end unit at a regular interval. The apparatus sends the first in the series of signal packets at a pre-determined pre-skew interval before the timing mark. The apparatus counts the number of clock cycles after the timing mark before the signal packet is received back at the network interface unit.

Abstract: In a digital communications system with a time-division multiplexed medium having a transmit r.f. channel and a receive r.f. channel on an internal network having a head end multiplexer and interface for external connection of calls, timeslots are allocated to maximize time slot usage between internal calls and external calls by dynamically differentiating between internal call types and external call types, or calls between nodes within the internal network between an internal node on the internal network and an external node connected through a trunk, and, based on differentiation for the external call types, claiming a free timeslot for the internal node on the transmit r.f. channel and using the corresponding timeslot on the receive r.f. channel to establish communication between the internal node and the external node.

Abstract: A baseband signal is spectrally efficiently transmitted on a broadband transmission medium by inserting gaps in packets of digital data transmitted in a modulated first radio frequency carrier. The transmitted packets of data are received by demodulating the modulated first radio frequency carrier, and the gap is monitored for the presence of digital data thus indicating a collision of simultaneously transmitted packets of digital data. A seed of arbitrary digital bits are used in scrambling each packet of digital data and is transmitted with the packet of data for use in descrambling the data. In retransmitting the packet of data the seed is included. The originally transmitting node receives the retransmitted packet and compares the retransmitted seed with the originally transmitted seed for detecting an error in retransmission.

Abstract: Apparatus for combining broadband RF signals and baseband signals in a baseband distribution cable includes a bridge for coupling the distribution cable to an RF broadband trunk and to a baseband repeater. The trunk is connected through bidirectional amplifier, an impedance transformer, and a signal splitter for applying the amplified and impedance transformed broadband signal to a plurality of baseband segments. The RF signal from the splitter is passed through a 35 MHz high pass filter to the baseband segment. Baseband signals from a repeater are passed through a 25 MHz low pass filter to the baseband segment. The two filters prevent interference between the baseband and broadband signals.

Abstract: A communication network having a first broadband communications channel or transmitting bus and a second broadband communications channel or receiving bus, wherein the first broadband communications channel is for passing information upstream to a head end and the second broadband communications channel is for passing information downstream from the head end to remote nodes. All nodes of the system are coupled to both the first communications channel and the second communications channel. According to the invention, modulation of signals applied to the first communication channel is optimized for burst communication from a plurality of sources to central control at the head end, and modulation applied to the second communications channel is optimized for continuous communication from the central source to a target node.

Abstract: A communication network having a first broadband communications channel or transmitting bus and a second broadband communications channel or receiving bus, wherein the first broadband communications channel passes information upstream to a head end employing an offset quadrature phase shift keyed (OQPSK) modulator in bursts, and the second broadband communications channel passes information downstream from the head end to remote nodes in a continuous bit stream. All nodes of the system are coupled to both the first communications channel and the second communications channel. According to the invention, modulation of signals applied to the first communication channel is optimized for burst communication from a plurality of sources to central control at the head end, and modulation applied to the second communications channel is optimized for continuous communication from the central source to a target node.

Abstract: A method and an apparatus for demodulating M-ary PSK signals of the type wherein the modulation is limited to phase transitions between adjacent phase states. The method is operative in a demodulator which comprises a phase splitter dividing a source signal into two paths with a preselected phase relationship among phases, one of the phases being delayed by nominally one bit period, a mixer or multiplier receiving as one input a representation of the delayed-phase component and as a second input a representation of the other phase component. A signal is filtered by a lowpass filter and provided to at least one corresponding two-level comparator, each of which produces a digital output. Digital logic circuitry responds to the digital outputs of each of the comparators to map the digital outputs into a single digital bit stream of ones and zeros.

Abstract: According to the invention, value errors in a recorded digital symbol are minimized by generating, from a high-speed sampling clock, a local clock which is synchronized to a selected sample time of a sampler which substantially over samples the received data stream, and then using the locally-generated clock to reconstruct the symbol synchronously with the locally-generated clock. The specific techniques are employed during the preamble of a synchronous system to select an optimum sample time for use in generating the local clock. Several specific techniques may be employed to mimize error. In order to find the center of a data symbol, particularly a binary digital data symbol in a digital data stream, a Read Only Memory (ROM) may be provided in which is stored all combinations of addresses of taps for the center of a symbol in response to address input representing the binary value of the signal in a shift register.

Abstract: A method and an apparatus for demodulating M-ary PSK signals of the type wherein the modulation is limited to phase transitions between adjacent phase states. The method is operative in a demodulator which comprises a phase splitter dividing a source signal into three paths with a preselected phase relationship among phases, one of the phases being delayed by nominally one bit period, a pair of mixers or multipliers, each one of the mixers receiving as one input a representation of the delayed-phase component and each one of the mixers receiving as a second input a representation of one of the other of the phase components. Combined signals are provided by the mixers to a combiner which adds or subtracts the combined signals according to expected input signal type to produce from one to N intermediate output signals. An intermediate output signal is coupled to a corresponding two-level comparator, each of which receives and responds to the respective intermediate output signals to produce a digital output.