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

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 and apparatus are described for providing multiple transmission bandwidth streams with differentiated quality of service on a inter-machine trunk. One approach includes time-division multiplexing. Another approach includes statistical multiplexing. Another approach includes packet segmentation. The approaches are commercially important because they significantly reduce time-delay variation.

Abstract: Systems and methods are described for carrier tracking. A center frequency of a signal is tracked by comparing spectral power contents of filtered versions of the signal. A receiver incorporates this carrier tracking. The systems and methods provide advantages because of decreased cost.

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

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 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 clock recovery and detection of rapid phase transients.

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 described for clock recovery and detection of rapid phase transients.

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

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 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 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 asymmetric digital subscriber loops.