Abstract: Systems and methods are described for modified asymmetric digital subscriber line for use with long loops. A method includes modifying a digital signal processor including reallocating a portion of an original guard band to a modified downstream band and reallocating a portion of an original upstream band to a modified guard band. An apparatus includes a digital signal processor defining an expanded downstream band; and a high pass filter coupled to the digital signal processor to accommodate the expanded downstream band.

Abstract: Systems and methods are described for deploying bonded G.shdsl links for ATM backhaul applications. A method includes transporting digital data including: coupling a first end of a plurality of unbundled network elements to a first modem; coupling a second end of the plurality of unbundled network elements to a second modem; providing the first modem with a first single stream of asynchronous transfer mode cells; sequence-cell division multiplexing to divide the first single stream of asynchronous transfer mode cells into a plurality of streams of cells at the first modem; transmitting the plurality of streams of cells to the second modem via the plurality of unbundled network elements; and sequence-cell division demultiplexing to bond the plurality of streams of cells into a second single stream of asynchronous transfer mode cells at the second modem.

Abstract: Systems and methods are described for bonding asynchronous transfer mode permanent virtual circuits using a multi-link segmentation and reassembly sublayer. A method includes: transforming a plurality of streams of asynchronous transfer mode cells into a stream of bonded asynchronous transfer mode cells, the plurality of streams of asynchronous transfer mode cells provided by a first plurality of permanent virtual circuits; demultiplexing the stream of bonded asynchronous transfer mode cells into a plurality of streams of inverse multiplexed bonded asynchronous transfer mode cells; and transmitting the plurality of streams of inverse multiplexed bonded asynchronous transfer mode cells to a remote location via a second plurality of permanent virtual circuits. The transmitted plurality of streams of inverse multiplexed bonded asynchronous transfer mode cells can be multiplexed and transformed into a plurality of multiplexed streams of asynchronous transfer mode cells after transmitting.

Abstract: Systems and methods are described for bonding multiple G.shdsl links. A method includes transporting digital data including: coupling a first end of a plurality of unbundled network elements to a first modem; coupling a second end of the plurality of unbundled network elements to a second modem; applying a single signal to the first modem; time division multiplexing the single signal into a plurality of signals at the first modem; transmitting the plurality of signals to the second modem over the plurality of unbundled network elements; receiving the plurality of signals at the second modem; and time division demultiplexing the plurality of signals to combine the plurality of signals into a single synchronous signal at the second modem. Each of the plurality of unbundled network elements includes a G.shdsl link.

Abstract: Systems and methods are described for bonding asynchronous transfer mode permanent virtual circuits using a multi-link segmentation and reassembly sublayer. A method includes: transforming a stream of asynchronous transfer mode cells into a stream of bonded asynchronous transfer mode cells; demultiplexing the stream of bonded asynchronous transfer mode cells into a plurality of streams of inverse multiplexed bonded asynchronous transfer mode cells; and transmitting the plurality of streams of inverse multiplexed bonded asynchronous transfer mode cells to a remote location via a plurality of permanent virtual circuits, characterized in that the transmitted plurality of streams of inverse multiplexed bonded asynchronized transfer mode cells can be multiplexed into a multiplexed stream of asynchronized transfer mode cells after transmission via at least two permanent virtual circuits, which compose the plurality of permanent virtual circuits, that do not have an identical bit-rate.

Abstract: Systems and methods are provided for interfacing between an element management system and a network management system in a network. A method includes associating a plurality of physical elements of a network with at least one element management system; providing a network management system; and providing a generic management information base interfacing between the at least one element management system and the network management system. The generic management information base includes a first data structure and a second data structure, the first data structure including at least one attribute common to each of the plurality of physical elements associated with the element management system, the second data structure including at least one value representing at least one of the plurality of physical elements. The first data structure and the second data structure are associated using a common link field and the first data structure and the second data structure are generic.

Abstract: Systems and methods are described for long subscriber loops using automatic gain control. A method includes extending a digital subscriber loop including: producing an output signal in a first direction from a variable gain amplifier at a mid-span extender unit responsive to an input signal in the first direction from the digital subscriber loop; monitoring a signal strength of said output signal in the first direction at the mid-span extender unit; generating a gain control signal responsive to the signal strength at the mid-span extender unit; controlling a gain of the variable gain amplifier at the mid-span extender unit responsive to the gain control signal; and controlling a second gain of a second variable gain amplifier at said mid-span extender unit responsive to said gain control signal to produce an output signal in a second direction from said second variable gain amplifier at said mid-span extender unit responsive to a second input signal in said second direction from said digital subscriber loop.

Abstract: A method of tracking a pilot channel to discipline an oscillator includes: downconverting the RF signal to a low frequency that is of the order of, but greater than the chip rate; converting the signal into digital format; computing complex correlations between the received digital signal and local replicas of the PN codes; and establishing from the correlation values what is the nominal frequency error of the local oscillator. Correlation values between the digital signal {s(n)} and at least one locally generated version of I-channel and Q-channel PN signals {IPN(n)} and {QPN(n)} are averaged over multiple periods of the PN signals. Pilot signal tracking accuracy is improved, computational load is reduced without degradation in performance, and the technique is simple enough to be incorporated in an off-the-shelf FPGA.

Abstract: A miniature optical system for use in instruments based on laser spectroscopy of atomic and molecular samples, such as atomic frequency standards and magnetometers. The miniature optical system employs a folded optical path that allows light from a laser diode to pass through the cell twice, reflecting from a mirror and returning to a photodetector co-located with the laser diode. This efficient packaging arrangement allows the laser diode and photodetector to be fabricated on the same semiconductor substrate and allows essentially all of the gas cell volume to be utilized, without additional optical components for collimation. Fabrication of the laser source and detector on a single substrate permits cost-effective batch processing and parallel testing of the key active components.

Abstract: Systems and methods are described for asymmetric digital subscriber loops.

Abstract: Systems and methods are described for a download booster for ADSL transmission. A method includes extending a digital subscriber loop including: coupling a telephone company central office to a customer premises via the digital subscriber loop; filtering a downstream digital subscriber loop signal at the customer premises; and amplifying the downstream digital subscriber loop signal at the customer premises. A method, includes: providing a digital subscriber loop service to a customer premises that is coupled to a telephone central office via a digital subscriber loop line; filtering a downstream digital subscriber loop signal at the customer premises; and amplifying the downstream digital subscriber loop signal at the customer premises.

Abstract: The invention comprises a method and apparatus for reducing uncertainty in timing on the network. The uncertainty in receive buffers is removed by time stamping the arriving packets before sending the packets to the receive buffer. The uncertainty in the transmission buffer is removed by giving the packets a timestamp in the future, and holding the packets until precisely that time. Time precision is ensured by only releasing time packets at the host physical layer to network boundary at the time specified within the packet.

Abstract: A method includes receiving a pair of input clock signals; utilizing a stratum clock state machine to control a multiplexer; utilizing the multiplexer to switch an input of a main clock between each of the pair of input clock signals; inducing a phase build-out activity; and transmitting an output clock signal.

Abstract: In an apparatus using optically excited atomic media, such as an atomic frequency standard, a source providing a controlled emission of light for exciting the D1 and/or D2 resonance lines of an alkali gas, such as rubidium or cesium, is controlled by an output generated by digital electronics from the light intensity signal of a light sensor for light transmitted by the alkali gas, an output for representing ambient temperature, and a light intensity-ambient temperature algorithm to substantially eliminate changes in light intensity due to light source aging for the purpose of reducing changes in temperature sensitivity of the apparatus as a function of time and the light-shift contribution to the frequency aging of the standard.

Abstract: Systems and methods are described for a core sync module. A method includes receiving a pair of input clock signals; utilizing a stratum clock state machine to control a multiplexer; utilizing the multiplexer to switch an input of a main clock between each of the pair of input clock signals; inducing a phase build-out activity; and transmitting an output clock signal. An apparatus includes a first input clock digital phase-locked loop; a second input clock digital phase-locked loop; a stratum clock state machine coupled to the first input clock digital phase-locked loop and to the second input clock digital phase-locked loop; and a main clock phase-locked loop coupled to the first input clock digital phase-locked loop, to the second input clock digital phase-locked and to the stratum clock state machine.

Abstract: Systems and methods are described for a GPS receiver capable of functioning in the presence of interference. A method includes detecting an interfering signal including: tuning a band pass filter over a frequency range; and at each of a plurality of incremental frequencies: computing a set of band pass filter coefficients; sending the set of band pass filter coefficients to a digital filter; repeatedly transforming an analog-to-digital converter output having a quantization level in excess of 2 bits into a band pass filter output with the digital filter to obtain a plurality of samples; computing an average of the plurality of samples; and comparing the average to a threshold to detect peaks that exceed a threshold.

Abstract: Systems and methods are described for fault detection for subscriber loop repeaters. A method includes monitoring an upstream signal on a digital subscriber loop for a fault detection signal that is added to said upstream signal at a repeater; and determining if a fault has occurred. An apparatus includes a digital subscriber loop fault detection system including: a receiver circuit that monitors an upstream signal on said digital subscriber loop for a fault detection signal that is added to said upstream signal at a repeater; and a logic circuit that determines whether a fault has occurred.

Abstract: Systems and methods are described for digital subscriber loop repeaters. A method of transforming a digital subscriber loop signals includes increasing a gain with a digital subscriber loop repeater including: isolating an upstream signal band by passing an upstream signal through an upstream pass filter; amplifying the isolated upstream signal with an upstream amplifier; isolating a downstream signal band by passing a downstream signal through a downstream pass filter; and amplifying the isolated downstream signal with a downstream amplifier. The systems and methods provide advantages because DSL can be provided over long loops and/or over coil loaded loops.

Abstract: Methods include receiving a pair of input clock signals; utilizing a stratum clock state machine to control a multiplexer; utilizing the multiplexer to switch an input of a main clock between each of the pair of input clock signals; inducing a phase build-out activity; and transmitting an output clock signal.

Abstract: Systems and method are described for clock recovery or detection of rapid phase transients.