Abstract: There is a need for a forensic diagnostic capability to facilitate a greater understanding of why xDSL transceivers are subject to otherwise inexplicable service interruptions during Showtime (steady state data transmission mode). In certain exemplary embodiments, diagnostic data from a previous Showtime is stored and then communicated to another transceiver and/or reported (or communicated) to a management entity. The stored diagnostic data can be used to determine why the service interruption occurred. In other embodiments, one or more portions diagnostic data from a last Showtime are stored. In additional embodiments, this diagnostic data is collected immediately prior to exiting Showtime and/or retraining (the “last” data collected prior to exiting Showtime and/or retraining).

Abstract: Using DSL modems as data collectors, the modems processes the data to, for example, allow easier interpretation of the line characteristics. In particular, the modems postprocess the data including calibration, filter compensation, determination of the SNR medley from the bits and gains tables and rate conversion. The interpretation process uses the postprocessed data and determines loop characterization, interferer detection, a data reduction estimation and a data rate estimation. The outputs of these determinations least allow for the characterization of the line conditions between the two modems.

Abstract: A system allocates shared memory by transmitting/receiving a message specifying a maximum number of bytes of memory that are available to be allocated to an interleaver. The system determines an amount of memory required by the interleaver to interleave a first plurality of RS coded data bytes within a shared memory and allocates a first number of bytes of the shared memory to the interleaver to interleave the first plurality of RS coded data bytes for transmission at a first data rate. The system also allocates a second number of bytes of the shared memory to a deinterleaver to deinterleave a second plurality of RS coded data bytes received at a second data rate and interleaves the first plurality of RS coded data bytes within the shared memory allocated to the interleaver and deinterleaves the second plurality of RS coded data bytes within the shared memory allocated to the deinterleaver.

Abstract: One exemplary aspect is to detect the presence of one or more types of faults affecting DSL communications. Upon their detection, a message can be generated that recommends corrective action. Furthermore, another exemplary aspect is to estimate the rate impact of the detected fault in some cases. One exemplary aspect of certain embodiments is to detect the presence of one or more faults that affect DSL communications, and upon their detection, generating, for example, a message that recommends corrective action. In this context, a fault can be one or more metallic faults, malfunctioning modems, or something else that affects the measured attenuation but is not normally attributable to normal DSL transmission lines.

Abstract: Upon detection of a trigger, such as the exceeding of an error threshold or the direction of a user, a diagnostic link system enters a diagnostic information transmission mode. This diagnostic information transmission mode allows for two modems to exchange diagnostic and/or test information that may not otherwise be exchangeable during normal communication. The diagnostic information transmission mode is initiated by transmitting an initiate diagnostic link mode message to a receiving modem accompanied by a cyclic redundancy check (CRC). The receiving modem determines, based on the CRC, if a robust communications channel is present. If a robust communications channel is present, the two modems can initiate exchange of the diagnostic and/or test information. Otherwise, the transmission power of the transmitting modem is increased and the initiate diagnostic link mode message re-transmitted to the receiving modem until the CRC is determined to be correct.

Abstract: A technique for controlling the quality of one or more compressed images. The technique allows, for example, the selection of a target quality metric(s) and the compression of the image(s) such the compressed image(s) meets the metric(s). Alternatively, a target quality metric can be specified, and the image(s) compressed using parameters estimated to achieve the target quality. Optionally, the quality metric can also be made available to, for example, a user on an image processing system. The quality metrics can be, for example, for one or more layers, one or more images and/or one or more image sequences.

Abstract: An alternative approach to coping with the ever increasing demand for faster communications hardware is to design modems that are capable of operating its speeds at a higher data rate than a speed required for a single port of the standard communication rate for that modem. Basically, by utilizing a resource manager, that directs the data in and out of the various portions of the modem in an orderly manner, keeping track of which of the ports is being operated at any given point in time, a standard single port modem can be reconfigured, for example, at an over clocked rate, to manipulate the data input and output of a modem.

Abstract: A multicarrier modem has a plurality of carriers over which data is transmitted. By assigning, foe example, one or more different margins to the individual carriers the data rate and impairment immunity can be increased.

Abstract: Upon detection of a trigger, such as the exceeding of an error threshold or the direction of a user, a diagnostic link system enters a diagnostic information transmission mode. This diagnostic information transmission mode allows for two modems to exchange diagnostic and/or test information that may not otherwise be exchangeable during normal communication. The diagnostic information transmission mode is initiated by transmitting an initiate diagnostic link mode message to a receiving modem accompanied by a cyclic redundancy check (CRC). The receiving modem determines, based on the CRC, if a robust communications channel is present. If a robust communications channel is present, the two modems can initiate exchange of the diagnostic and/or test information. Otherwise, the transmission power of the transmitting modem is increased and the initiate diagnostic link mode message re-transmitted to the receiving modem until the CRC is determined to be correct.

Abstract: A ridge flow based fingerprint image quality determination can be achieved independent of image resolution, can be processed in real-time and includes segmentation, such as fingertip segmentation, therefore providing image quality assessment for individual fingertips within a four finger flat, dual thumb, or whole hand image. A fingerprint quality module receives from one or more scan devices ridge-flow—containing imagery which can then be assessed for one or more of quality, handedness, historical information analysis and the assignment of bounding boxes.

Abstract: A system and method that demodulates the phase characteristic of a carrier signal are described. The scrambling of the phase characteristic of each carrier signal includes associating a value with each carrier signal and computing a phase shift for each carrier signal based on the value associated with that carrier signal. The value is determined independently of any input bit value carried by that carrier signal. The phase shift computed for each carrier signal is combined with the phase characteristic of that carrier signal so as to substantially scramble the phase characteristic of the carrier signals. Bits of an input signal are modulated onto the carrier signals having the substantially scrambled phase characteristic to produce a transmission signal with a reduced PAR.

Abstract: A system or method in an OFDM communication environment includes transmitting, by a transmitter, and/or receiving, by a receiver, a frame that includes one or more preamble symbols, one or more header symbols, a plurality of data symbols, and a plurality of probe symbols. The probe symbols are predefined symbols that do not carry user data and are generated by modulating a predefined pseudo-random bit sequence (PRBS). A frame header, communicated in the one or more header symbols, includes one or more bit fields that indicate that the frame includes N probe symbols, wherein N is an integer greater than 1, and wherein the plurality of probe symbols are transmitted or received after the one or more header symbols and before the plurality of data symbols.

Abstract: A system and method that demodulates the phase characteristic of a carrier signal are described. The scrambling of the phase characteristic of each carrier signal includes associating a value with each carrier signal and computing a phase shift for each carrier signal based on the value associated with that carrier signal. The value is determined independently of any input bit value carried by that carrier signal. The phase shift computed for each carrier signal is combined with the phase characteristic of that carrier signal so as to substantially scramble the phase characteristic of the carrier signals. Bits of an input signal are modulated onto the carrier signals having the substantially scrambled phase characteristic to produce a transmission signal with a reduced PAR.

Abstract: An OFDM communication system is described that allows different values of D in a single domain where nodes are operating in different portions of frequency bands. For the power-line medium, G.9960 has defined two over-lapped baseband bandplans, 50 MHz-PB and 100 MHz-PB. In this exemplary scenario, the level of frequency diversity is different depending on the bandplan, hence providing different header decodibility if D is fixed to 1. If D is fixed to 2, then it increases reliability for the narrow-band devices, but may also unnecessarily increase overhead for the wide-band devices. An exemplary aspect is therefore directed to techniques to accommodate different repetitions schemes (D=1, . . . , DMAX and H=I, . . . , HMAX) in a single domain, and still allow devices to communicate with one another where DMAX and HMAX can be larger than 2.

Abstract: Using DSL modems as data collectors, the modems processes the data to, for example, allow easier interpretation of the line characteristics. In particular, the modems postprocess the data including calibration, filter compensation, determination of the SNR medley from the bits and gains tables and rate conversion. The interpretation process uses the postprocessed data and determines loop characterization, interferer detection, a data reduction estimation and a data rate estimation. The outputs of these determinations least allow for the characterization of the line conditions between the two modems.

Abstract: A technique for controlling the quality of one or more compressed images. The technique allows, for example, the selection of a target quality metric(s) and the compression of the image(s) such the compressed image(s) meets the metric(s). Alternatively, a target quality metric can be specified, and the image(s) compressed using parameters estimated to achieve the target quality. Optionally, the quality metric can also be made available to, for example, a user on an image processing system. The quality metrics can be, for example, for one or more layers, one or more images and/or one or more image sequences.

Abstract: By utilizing Reed-Solomon erasure decoding algorithms and techniques, the system is able to perform error detection for the case where the number of bytes received in error exceeds a correcting capability of a decoder. The error detection can be used, for example, to determine whether a codeword is decodable, and whether the retransmission of data is necessary. The retransmission can be accomplished by assembling a message that is sent to another modem requesting retransmission of one or more portions of data, such as one or more codewords.

Abstract: An alternative approach to coping with the ever increasing demand for faster communications hardware is to design modems that are capable of operating its speeds at a higher data rate than a speed required for a single port of the standard communication rate for that modem. Basically, by utilizing a resource manager, that directs the data in and out of the various portions of the modem in an orderly manner, keeping track of which of the ports is being operated at any given point in time, a standard single port modem can be reconfigured, for example, at an over clocked rate, to manipulate the data input and output of a modem.

Abstract: An alternative approach to coping with the ever increasing demand for faster communications hardware is to design modems that are capable of operating its speeds at a higher data rate than a speed required for a single port of the standard communication rate for that modem. Basically, by utilizing a resource manager, that directs the data in and out of the various portions of the modem in an orderly manner, keeping track of which of the ports is being operated at any given point in time, a standard single port modem can be reconfigured, for example, at an over clocked rate, to manipulate the data input and output of a modem.

Abstract: Methods and apparatus for constructing objects within a cache system thereby allowing the cache system to respond to requested objects that are not initially available within the cache system. One embodiment of the invention caches image files, where the images are divided into components and stored in a format that allows identification and access to the components. The cache system determines that an object, such as an image file, is missing from the cache memory, locates sufficient components from the cache memory and/or external storage, and constructs the object from the located components.