Abstract: An embodiment of the invention provides communications services to Optical Network Terminals (ONTs) in a Passive Optical Network (PON) with at least two Optical Line Terminals (OLTs). The role of these OLTs is autonomously governed based on characteristics of upstream signals from the ONTs. When an OLT in a standby mode determines that upstream signal power is below a power threshold, the OLT in standby mode changes its mode and operates in the active mode. An OLT in active mode monitors the upstream signals and determines the number of upstream signals that are misaligned to a respective downstream command sent from the active OLT. When the number of misaligned signals is greater than a counts threshold, the active OLT switches its operation and operates in standby mode. Through autonomous operation, the OLTs provide redundancy for the PON without added control channel complexity.

Abstract: Typical passive optical networks (PONs) employ several optical network terminals (ONTs) connected to an optical line terminal (OLT) via an optical splitter/combiner (OSC). Due to the passive nature of the OSC, determining a port assignment of an ONT may be difficult or impossible. Methods described herein provide for identifying a port in a passive optical network, optionally as corresponding to an ONT. A first subset of the ONTs is caused to transmit a first signal, such as a status signal, with a respective attribute having a first value, and a second subset of the ONTs is caused to transmit a second signal with the respective attribute having a second value. At the OSC, the signals are detected as a function of the attribute and the first and second values. Results of this detection are reported, from which an identification of a port and associated ONT can be determined.

Abstract: An embodiment of the invention provides communications services to Optical Network Terminals (ONTs) in a Passive Optical Network (PON) with at least two Optical Line Terminals (OLTs). The role of these OLTs is autonomously governed based on characteristics of upstream signals from the ONTs. When an OLT in a standby mode determines that upstream signal power is below a power threshold, the OLT in standby mode changes its mode and operates in the active mode. An OLT in active mode monitors the upstream signals and determines the number of upstream signals that are misaligned to a respective downstream command sent from the active OLT. When the number of misaligned signals is greater than a counts threshold, the active OLT switches its operation and operates in standby mode. Through autonomous operation, the OLTs provide redundancy for the PON without added control channel complexity.

Abstract: Typical passive optical networks (PONs) employ several optical network terminals (ONTs) connected to an optical line terminal (OLT) via an optical splitter/combiner (OSC). Due to the passive nature of the OSC, determining a port assignment of an ONT may be difficult or impossible. Methods described herein provide for identifying a port in a passive optical network, optionally as corresponding to an ONT. A first subset of the ONTs is caused to transmit a first signal, such as a status signal, with a respective attribute having a first value, and a second subset of the ONTs is caused to transmit a second signal with the respective attribute having a second value. At the OSC, the signals are detected as a function of the attribute and the first and second values. Results of this detection are reported, from which an identification of a port and associated ONT can be determined.

Abstract: A media access control (MAC) layer address translation system is included in a fiber to the home (FTTH) system having a central office that interfaces a packet data network with a passive optical network (PON). The (MAC) layer address translation system includes a home network unit (HNU), a host system, and a MAC address table. The HNU is coupled to the PON and has an associated base MAC layer address and an associated secondary MAC layer address that identify the HNU within the PON. The host system is coupled in a network to the HNU and has an associated host MAC layer address that identifies the host system within the network. The MAC address table is stored in a memory device, and associates the host MAC layer address with the secondary MAC layer address.

Abstract: A ground fault interrupt (GFI) circuit detects and interrupts a ground fault, even in the presence of AC power induced currents. The GFI circuit can be used for power delivery between nodes in a network, such as from a central office to remote network equipment. The GFI circuit meets GFI specifications covering such an application. The GFI circuit detects rapid changes and slow rises in ground fault current. Safety features, such as intermittent interruptions of power on power lines in an event of a ground fault, are supported by the GFI circuit to protect field personnel. A digital processor may be used to implement aspects of the GFI circuit to support changes of or various operating environments.

Abstract: An energy storage system and corresponding method, provides an efficient use of stored energy and more regulated power to an output terminal in the event of an interruption in line input power. In one embodiment, an energy storage system has a pulse width modulation (PWM) DC-DC converter module configured to convert line input power to a first regulated output at an output terminal. A pump storage module is coupled to the PWM DC-DC converter module at the output terminal and stores energy from the first regulated output and converts the stored energy to a second regulated output. The energy storage system has a logic unit coupled to the converter module to cause the converter module and pump storage module to transition power at the output terminal from the first regulated output power to the second regulated output power in an event of interruption in the line input power.

Abstract: A technique for multiplexing high speed computed data with digitized voice signals onto a fiber optic cable for transfer to a local central office. The data packets of a number of computers are networked by way of a distributed hub that extends to residences, offices, apartments, etc. The data packets are switched outside the switching fabric of a local central office and routed to the internet or elsewhere. Command signals that are for accessing the internet are transmitted and received as 10 MHz Ethernet data packets on the distributed hub.

Abstract: A digital packet access network for transporting voice and data signals in the local loop between a central office location and a plurality of remote local users. The network architecture may also include: (1) a dual-pipelined structure for separately transporting the voice and data signals; (2) a mechanism for prioritizing the transport of the voice signals; or (3) a method of synchronizing the timing of the voice signals to a telephone switch.

Abstract: A digital laser driver circuit is provided in which a digital synthesizer synthesizes a modulation index signal for precisely setting the modulation level of the laser, and a pair of feedback loops control the average power level and modulation index of the laser diode. The laser diode includes a back-facet photodiode that is used to monitor the laser's average and peak optical power levels. The average power level is measured by an analog feedback loop and compared to an externally supplied reference voltage in order to maintain the laser at a particular average optical power level. The peak power is measured by a digital feedback loop and compared to a pair of threshold levels based on a ratio of the average power level using digital comparators. The comparators provide signals to the digital synthesizer in order to indicate that the modulation level is too low or too high.

Abstract: A media access control (MAC) layer address translation system is included in a fiber to the home (FTTH) system having a central office that interfaces a packet data network with a passive optical network (PON). The (MAC) layer address translation system includes a home network unit (HNU), a host system, and a MAC address table. The HNU is coupled to the PON and has an associated base MAC layer address and an associated secondary MAC layer address that identify the HNU within the PON. The host system is coupled in a network to the HNU and has an associated host MAC layer address that identifies the host system within the network. The MAC address table is stored in a memory device, and associates the host MAC layer address with the secondary MAC layer address.

Abstract: A linear laser diode driver circuit is provided in which a solid state laser diode and its back-facet photodiode are configured into the feedback loop of a high-speed operational amplifier. In this configuration, the light output from the laser diode is directly proportional to the input voltage to the operational amplifier and is independent of the laser diode's temperature characteristics.

Abstract: Circuitry for controlling a diode optically coupled to an optical fiber suitable for transmitting digital light signals therethrough. The circuitry includes a temperature compensated driver when operating in the transmit mode and receiving circuitry for conditioning and amplifying electrical signals generated by the diode when it operates in a photodetection mode. A sweep circuit is provided for isolating amplifiers in the receiving circuitry and for discharging residual charge left in the diode during the transmission mode thereby reducing the signal-to-noise ratio.

Abstract: A technique for multiplexing high speed computed data with digitized voice signals onto a fiber optic cable for transfer to a local central office. The data packets of a number of computers are networked by way of a distributed hub that extends to residences, offices, apartments, etc. The data packets are switched outside the switching fabric of a local central office and routed to the internet or elsewhere. Command signals that are for accessing the internet are transmitted and received as 10 MHz Ethernet data packets on the distributed hub.

Abstract: A technique for multiplexing high speed computed data with digitized voice signals onto a fiber optic cable for transfer to a local central office. The data packets of a number of computers are networked by way of a distributed hub that extends to residences, offices, apartments, etc. The data packets are switched outside the switching fabric of a local central office and routed to the internet or elsewhere. Command signals that are for accessing the internet are transmitted and received as 10 MHz Ethernet data packets on the distributed hub.

Abstract: A Fiber-to-the-Home (FTTH) multi-media access system and method are provided in which voice, video and data signals are transported over a passive optical network (PON) between a central office location and a plurality of subscriber home network units (HNUs). Optical video distribution circuitry and telephony/data distribution circuitry at the central office location are included in the system and operate to send and receive CATV video, PBS video television, telephony and Packet data signals to and from the HNUs via the PON. Optical multiplexing/demultiplexing circuitry operating at the central office combines the video signals, which are operating at one optical wavelength, with the telephony/data signals, which are operating at a second, distinct optical wavelength. These combined optical signals are then transported over the PON to the HNUs.

Abstract: A four quadrant current mode switching amplifier is provided. The switching amplifier includes a pulse width modulator (PWM) programmed by an error voltage derived from an analog input voltage and the amplified output voltage. The PWM is also provided with negative current mode feedback in all four quadrants of operation. A logic device controls the switching topology to source, or sink power for the load and to provide negative or positive output in dependence upon sign and slope bits, derived from the input and output voltages, and the PWM output.

Abstract: A digital transmission system which serves a multiplicity of subscribers by a multiplicity of channel units. Each channel unit serves up to two subscribers. At each end of the system, there is included a signaling processing unit (SPU) which provides both time slot interchanging and change in format for the signaling information. At each end of the system, there is another unit (TRU) which provides time slot interchanging for the nonsupervisory information for each subscriber. The channel units are arranged in channel banks for four groups of units each. Each channel bank is connected to the SPU by two single lines over one of which all the supervisory (signaling, provisioning and testing) information for the units in the bank is transmitted and over the other of which all the supervisory information from the units is transmitted. The TRU is connected to each group in the bank by a pair of lines.

Abstract: A voltage controlled oscillator which may be used in the receiver of a communications system, such as a carrier telephone system, for aiding in the demodulation of received carrier signals. The oscillator includes circuitry for generating first and second reference signals at a frequency equal to the carrier signal. Also included in the oscillator is circuitry which in response to the magnitude of an error signal variably connects a frequency determining electrical parameter to the frequency generating circuitry to thereby vary the frequency of the reference signals. The error signal magnitude represents the difference in phase between the carrier signal and the first reference signal.

Abstract: A frogging signal repeater for a transmission line communications system such as a telephone system having a trunk line connected between a pair of signal sources such as end central offices and/or standard signal repeaters. Each signal source generates information signals on a group of relatively high frequency carrier signals and receives information signals on a group of relatively low frequency carrier signals with the frogging signal repeater connected in the trunk line for translating the high and low frequency groups.