Abstract: Stations in standby mode periodically wake up to check for buffered data at the access points. Traditionally, the information is available by checking the periodic beacon frame for a traffic indication map (TIM). Unfortunately, the length of beacons has steadily increased with the progression of the various wireless standards requiring stations to wake up for longer periods to merely check for buffered data. Several approaches are disclosed which address this shortcoming, including the broadcast of TIM frames, the partial reception of beacon frames and the use of an embedded TIM frame within a beacon frame.

Abstract: A system and method for wireless waking computing devices over a computer network is provided. A signal is broadcast over the network that includes one or more device specific wake-up data sequences. Each device specific wake-up data sequence includes multiple iterations of the hardware address of the wireless network card associated with that device. While in a reduced power or “sleep mode”, the wireless network card monitors wireless channels for packets containing a wake-up data sequence. If a wake-up data sequence is received, the sequence is matched against the hardware address information for that network card. If a match is determined, the network card sends a signal to the computing device causing full system power to be restored. A signal is sent to the network confirming that the device has been successfully woken from the sleep mode.

Abstract: Systems and methods for reducing the peak-to-average power ratio (PAR) at the transmitter can reduce the dynamic range required in various analog components. PAR can be reduced by applying a time-domain compensation signal in the oversampled regime, using tones reserved for PAR reduction. A set of vectors corresponding to PAR tones is generated by processing out-of-phase symbols for each PAR tone to form a span matrix. The span matrix is used to find a best fit of a desired target signal to a time-domain compensation signal comprising only PAR tones.

Abstract: Systems and methods for performing loop length estimation are described. One embodiment includes a method which comprises receiving an echo signal for a loop under test where the echo signal is a per-port calibrated echo response obtained using frequency domain reflectometry single-ended line testing (FDR-SELT). The method further comprises analyzing characteristics of the echo signal to perform a loop length estimation based on data relating to ripple frequency as a function of loop length.

Abstract: Stations in standby mode periodically wake up to check for buffered data at the access points. Traditionally, the information is available by checking the periodic beacon frame for a traffic indication map (TIM). Unfortunately, the length of beacons has steadily increased with the progression of the various wireless standards requiring stations to wake up for longer periods to merely check for buffered data. Several approaches are disclosed which address this shortcoming, including the broadcast of TIM frames, the partial reception of beacon frames and the use of an embedded TIM frame within a beacon frame.

Abstract: Stations in standby mode in a wireless local area network (WLAN) become disassociated with their access point. In the event traffic is intended for the station in standby mode, a wakeup message needs to be communicated to the station. Typically, a wakeup message could be broadcast on a broadcast or multicast address, and when the station checks for broadcasts, the station can determine whether it needs to wake up. However, in a protected network, a disassociated station cannot decrypt messages from the access point without reassociating. However, the cost of reassociating in time and power can be significant, so reassociating should not be performed unless the station needs to wake up, leading to a vicious cycle as the station does not know it must wake up unless it can decrypt the message. To address this issue, in one embodiment the access points do not encrypt messages on a select multicast address, whereby messages such as wakeup message can be transmitted.

Abstract: Systems and methods for performing loop termination are described. One embodiment is a method that comprises receiving a per-port calibrated echo signal of a loop under test, receiving a region designation and a loop length for the loop under test, and determining whether the loop is terminated by a short or open termination based on phase of the per-port calibrated echo signal.

Abstract: A telecommunication receiver provided according to the present invention is implemented to receive a first signal containing information and noise on a first set of sensors and a second signal containing only noise on a second set of sensors. Receiver then decodes the information using first signal and second signal. In one embodiment, a bonded DSL receiver with k signals sensors is implemented with additional s number of noise only sensors to receive only noise. Accordingly, joint demodulation is performed using signals received on k signals sensors and s noise only sensors. The noise sensor is implemented in common mode.

Abstract: Systems and methods for broadcast and multicast retransmissions within a protected wireless communications system are described. Retransmitted broadcast or multicast frames are designated by modification of fields or subfields in the MAC header of the frame which are constituent parts of the additional authentication data used to generate encryption keys. Such modifications cause legacy receivers to disregard the retransmitted frames or render legacy receivers to be unable to decrypt the retransmitted frame, avoiding the generation of duplicate frames. Non-legacy receivers recognizing the modification conventions can restore the MAC header to the original state and can reconstruct the original encryption keys and decrypt the retransmitted frames. A non-legacy transmitter can retransmit a frame without the need to re-encrypt the frame.

Abstract: Systems and methods for performing bridge tap detection are described. One embodiment is a method which comprises receiving an echo signal for a loop under test where the echo signal is a per-port calibrated echo response obtained using frequency domain reflectometry single-ended line testing (FDR-SELT). The method further comprises analyzing the echo signal to determine whether differentiating features are present in the per-port calibrated echo signal in order to determine whether the loop under test is a bridge tapped loop.

Abstract: Stations in standby mode periodically wake up to check for buffered data at the access points. Traditionally, the information is available by checking the periodic beacon frame for a traffic indication map (TIM). Unfortunately, the length of beacons has steadily increased with the progression of the various wireless standards requiring stations to wake up for longer periods to merely check for buffered data. Several approaches are disclosed which address this shortcoming, including the broadcast of TIM frames, the partial reception of beacon frames and the use of an embedded TIM frame within a beacon frame.

Abstract: Broadcast and multicast (BM) systems have not been reliable in the wireless local area networks. Higher bandwidth and more reliable BM transmissions are necessitated by video and audio applications. A class of BM reliable frames is transmitted at a higher rate. The access point performs some rudimentary collision avoidance to enhance reliability, and individual stations are given the ability to send feedback to the access point regarding the quality of the transmission.

Abstract: Systems and methods for performing loop gauge detection are described. One embodiment is a method that comprises receiving a calibrated per-port echo signal of a loop under test, receiving a loop length estimation for the loop under test, and estimating the loop gauge of the loop under test if the loop is not determined to be a long loop based on a predetermined threshold and if no bridge tap is present on the loop. In accordance with such embodiments, estimating the loop gauge of the loop under test is based on at least one of the following echo signal features: energy of the echo signal in a predetermined frequency band, information on an envelope of maxima for the echo signal, information on an envelope of minima for the echo signal, and a span of ripples on the amplitude of the echo signal.

Abstract: Methods and systems of low density parity check coded (LDPCC) coding are disclosed herein in which a set of LDPC codes ensure reliable transmission for channels in which modulation symbols may undergo attenuation in a random fashion. Methods and systems of LDPC coding disclosed herein include choosing a code blocklength and concatenating codewords into which a data packet can be encoded. To optimize the coding scheme, first, codeword shortening is performed to ensure an integer number of codewords for a desired packet length. The codewords may then be punctured or repeated to ensure an integer number of channel symbols per codeword. Shortening and puncturing repetition methods are implemented to yield minimum overhead while keeping the effective coding rate low.

Abstract: A system for and method of converting successive bits of digital data into BPSK symbols using one or more BPSK symbol constellations such that orthogonal BPSK constellations are referenced to successive bits of the digital data. The system and method may toggle between referencing first and second orthogonal constellations as successive bits of the digital data are encountered. Alternatively, the system and method may successively rotate by 90° the constellation to be referenced as successive bits of the digital data are encountered. The reversal of the systems and methods described can be used to decode a transmission made by the methods described or specifically to reference a succession of orthogonal BPSK constellations to convert a succession of BPSK symbols to a succession of bits of digital data. Furthermore, a standard quadrature receiver can be used to perform the conversion.

Abstract: Systems for suppressing image noise are provided. In this regard, one embodiment includes a system for suppressing image noise comprising a low noise amplifier (LNA) configured to amplify a received RF signal, an RF variable gain attenuator with an image rejection filter with programmable bandwidth configured to suppress image noise and image interference, and an RF mixer configured to perform frequency translation.

Abstract: Systems involving temperature compensation of voltage controlled oscillators are provided. In this regard, a representative system incorporates: a voltage controlled oscillator (VCO) having a tuning port and a phase-locked loop (PLL); and a temperature dependent voltage source. The VCO selectively exhibits one of a coarse tuning mode in which the temperature dependent voltage source is electrically connected to the VCO tuning port, and a locked mode in which the temperature dependent voltage source is not electrically connected to the VCO tuning port such that the PLL controls the frequency of the VCO.

Abstract: Included are embodiments for facilitating communication. At least one embodiment of a method includes receiving first communication data from a communications device and creating an acknowledgment indicating receipt of the first communication data. Some embodiments include determining whether second communication data has been received for the communications device and in response to determining that data has been received for the communications device, combining the second communication data with the acknowledgement in a single data packet.

Abstract: Systems and methods for retrieving data from an access point within a wireless communications system are described. At least one embodiment includes a method for retrieving buffered data in a wireless communication system. In accordance with some embodiments, the method comprises transmitting a paging request to a plurality of access points while in a low power mode, receiving a Paging Indication element or a TIM Response element while remaining in low power mode, and exiting low power mode if buffered data is present and retrieving the buffered data. The Paging Indication element or TIM Response element indicates whether buffered data is present.

Abstract: Systems and methods are provided. In this regard, a representative system incorporates a crystal oscillator circuit and a digital automatic level control circuit. The digital automatic level control circuit is operative to: convert an oscillation amplitude of the crystal oscillator circuit to a proportional DC voltage; convert the DC voltage to a corresponding digital code representation; and adjust bias current and oscillator loop gain such that a desired oscillation amplitude is set.