Abstract: A high efficiency line driver is disclosed. The line driver may be applied with equal advantage in wired and wireless communication media to amplify data signals with a minimum of power consumption. In an embodiment of the invention a line driver is disclosed which includes: at least one amplifier, a delay element, a control signal generator and a generator. The at least one amplifier includes at least one bias supply, a signal input and a signal output. The delay element accepts as an input the data signal and delays delivery of the data signal to the at least one line amplifier for amplification. The generator is responsive to a control signal to generate varying voltage levels corresponding thereto on the at least one bias supply of the at least one amplifier. The control signal generator is responsive to the input data signal to detect peaks therein and to generate the control signal corresponding thereto in advance of delivery of the data signal to the amplifier.

Abstract: An apparatus and method is disclosed for channel estimation in an X-DSL communication device. The communication device may include physical or logical modems. The modems may implement one or more of a group of X-DSL protocols including: G.Lite, ADSL, VDSL, and HDSL. The apparatus may be used for determining the location and magnitude of discontinuities or faults within the communication medium to which the X-DSL communication device is coupled. The information provided by the device may be used for line qualification or repair. No additional equipment is required for channel estimation. Instead the apparatus may be located within a single modem or shared between a group of modems. An N bit pseudo random codeword injected into the transmit path is used to generate both a leakage signal and a plurality of reflected signals on the receive path. No timing information is needed from the transmit path.

Abstract: A method and apparatus for time and frequency domain forward error correction (FEC) in a modem which communicates data using multiple discrete sub-channels is provided. The invention may be implemented in hardware, software or firmware. In an embodiment of the invention a modem with a plurality of components forming a transmit path and a receive path is disclosed. The modem communicates data across a wired or wireless communication medium using a multiplicity of discrete sub-channels. The modem includes a transform component and a time domain FEC component. The transform component transforms the multiplicity of discrete sub-channels of a communication between a time domain and a frequency domain on the receive path and vice-versa on the transmit path. The time domain FEC component couples to the transform component. The time domain FEC component has a complementary encoder and decoder portion on the transmit and receive paths respectively.

Abstract: An apparatus and method for reducing interference over a common communication medium, wired or wireless is provided. The apparatus reduces interference from a number of sources using a common architecture which may be used to service a modem pool or discrete modems which share the common communication medium. Interference due to near end cross-talk (NEXT), self-NEXT or echo, and far end cross-talk (FEXT) may all be substantially reduced or cancelled by the apparatus. Additionally, channel characteristics for individual data channels across the common communication medium may be determined. The apparatus provides support for multiple modem protocols including X-DSL protocols such as G.Lite, ADSL, VDSL, SDSL, MDSL, RADSL, and HDSL. The apparatus supports multiple line codes such as the discrete multi-tone (DMT) and carrier less AM/PM (CAP) line codes associated with X-DSL communications. The apparatus may be implemented in hardware, firmware or software.

Abstract: An apparatus and method is provided for minimizing frequency distortion in the transmit path of an XDSL modem implementing digital multi-tone (DMT) line code. The current invention provides a means for both determining and correcting for distortion in the frequency domain. The apparatus may be incorporated in an existing X-DSL architecture without additional circuitry. In an embodiment of the invention the apparatus may include a calibration phase which may be implemented using the existing analog-to-digital (ADC) conversion and demodulation capabilities on the receive path of the modem. This calibration phase takes place before the training phase associated with establishing communications with a remote site. During the calibration phase a calibration sequence with known spectral characteristics in the frequency domain is injected digitally at the beginning of the transmit path into each of the tone bins of the inverse Fourier Transform engine (IFFT).

Abstract: A digital camera has a plurality of fields of view combined with a panning and/or tilting functionality. The camera comprises: a camera housing (6) with an optical input (5), such as a lens or objective. The camera also has an image capturing unit for producing a digital image from light received through the optical input, a controller, a mirror (1) having a first plane surface (12) and a second curved surface (13), and a driving device (7) coupled to the mirror and adapted to rotate the mirror to a first position, where the first plane surface is inserted into an optical path (31) of the digital camera, thereby providing a first field of view of the digital camera. The driving device is also adapted to rotate the mirror to a second position, where the second curved surface is inserted into the optical path of the digital camera, thereby providing a second field of view of the digital camera.

Abstract: An X-DSL modem supporting multiple X-DSL line codes including discrete multi-tone (DMT) and carrierless phase and amplitude (CAP). The modem includes: components coupled to one another to form a transmit path and a receive path. The components include an encoder component and a Fourier transform component. The encoder component encodes data associated with a CAP communication channel into QAM symbols and encodes data associated with a DMT communication channel into DMT sub-symbols. The Fourier transform component couples to the encoder component on the transmit path for transforming DMT sub-symbols from a frequency-to-time domain and for transforming QAM symbols from the time-to-frequency domain followed by a filtering in the frequency domain and a subsequent transformation back from the frequency-to-time domain to effect a pulse shaping function without requiring a discrete pulse shaping component in the transmit path.

Abstract: The current invention provides a DSP which accommodates multiple current X-DSL protocols and is further configurable to support future protocols. The DSP is implemented with shared and dedicated hardware components on both the transmit and receive paths. The DSP implements both the discrete Fourier transform (DFT) and inverse discrete Fourier transform (IDFT) portions across a wide range of sample sizes and X-DSL protocols. Multiple channels, each with varying ones of the X-DSL protocols can be handled in the same session. The DSP offers the speed associated with hardware implementation of the transforms and the flexibility of a software only implementation. Traffic flow is regulated in the chip using a packet based schema in which each packet is associated with a specific channel of upstream and downstream data. Header and control information in each packet is used to govern the processing of each packet as it moves along either the transmit path or receive path.

Abstract: A method and apparatus for digital subscriber line (xDSL) communications between one or more digital signal processors (DSPs) and analog front ends (AFEs) each coupled to corresponding subscriber line(s). The apparatus transports channels of data between subscribers and the DSP(s). The apparatus includes a bus for the transport of digital data, a DSP AFE interfaces. The DSP interfaces couples the DSP to the bus. The DSP interface accepts downstream channels of digital data from the DSP and transmits packets each associated with a corresponding one of the downstream channels to the bus. Each of the packets identifies a targeted AFEs coupled to a selected one of the subscriber lines. The AFE interfaces each couple an associated one of the AFEs to the bus. Each of the AFE interfaces transmits selected packets to a selected one of the subscriber lines for the transport to the subscriber.

Abstract: A method and apparatus for compensating an amplifier is disclosed which significantly improves the unity gain bandwidth of the amplifier. In an embodiment of the invention the amplifier includes at least one compensated pair of cascode coupled transistors including: an input transistor, a cascode transistor, and a bypass element. The input transistor exhibits a first transition frequency. The cascode transistor is cascode coupled to the input transistor. The cascode transistor exhibits a second transition frequency less than or equal to the first transition frequency of the input transistor. The bypass element couples across a corresponding current interface of the cascode transistor to substantially bypass the cascode transistor at a pole frequency thereof.

Abstract: A method and apparatus is disclosed for providing a range of location dependent information and services to users of wireless devices coupled to the multi-point wireless access network of the current invention. In an embodiment of the invention a multi-point wireless access network for servicing wireless devices is provided. The multi-point wireless access network includes: wireless access devices, an inventory map and a server. The wireless access points are arrayed in a coordinate system with a known relative relationship to one another. Each of the wireless access points provides communication capabilities for corresponding proximate ones of the wireless devices. The inventory map correlates selected ones of the wireless access points with corresponding inventory located proximate to each of the selected ones of the wireless access points.

Abstract: An apparatus and method is provided for minimizing in channel distortion in an X-DSL line driver is disclosed. The apparatus may be incorporated in an existing X-DSL architecture without additional circuitry. Out of band monitoring of a channel is implemented to adaptively minimize out of band interference and in band distortion. A unique training sequence, suitable for DMT line codes is set forth. The training sequence allows a full spectral characterization of the downstream signal space with a single upstream monitoring tone. The invention may be used with multi-channel X-DSL line drivers interfacing with any of a number of multi-channel supply architectures. The apparatus may be applied with equal advantage to communication protocols other than X-DSL. The apparatus may be applied with equal advantage in wired and wireless media.

Abstract: The current invention provides a digital signal processor which supports multiple X-DSL protocols and a multiplicity of channels on a single chip. Each channel is packetized and each packet includes control information for controlling the performance of the components/modules on the transmit and receive path. Further flexibility is derived from an architecture which incorporates discrete and shared modules on the transmit path and the receive path. The transmit path and receive path modules are collectively controlled by control information in selected ones of the packets and operate on each channel's packets at an appropriate rate, and protocol for the channel. A digital signal processor (DSP) is disclosed which incorporates these features. The DSP exhibits a favorable form factor, and flexibility as to protocols and line codes, and numbers of channels supported.

Abstract: An apparatus for storing digital images has a storage device for storing a current reference image and a plurality of differential images, and an image processing device coupled to the storage device. The image processing device receives an individual digital image, determines a difference between the individual image and the current reference image, and stores this difference as a differential image in the storage device. The apparatus also has reference image updating means for determining when to generate a new reference image, for generating the new reference image, for replacing the current reference image with the new reference image, and for storing the new reference image as current reference image in the storage device.

Abstract: A data storage and reduction method for digital images having a chronological order involves storing a first and chronologically new image or group of images at a first image quality requiring a first amount of storage space, and processing a second image or group of images, chronologically older than said first image or group of images, by reducing the image quality thereof to a second image quality requiring a second amount of storage space, which is less than said first amount of storage space. Advantageously, the method is used for a surveillance system, comprising a camera, a digital storage device and an image storage controller, wherein image quality is reduced for old or otherwise less important images or groups of images, thereby obtaining additional storage space for allowing more important images (such as images relating to an alarm event) to be stored at higher image quality, while retaining an extended total recording time span.

Abstract: A method and apparatus for coupling an xDSL transceiver with a subscriber line is disclosed. A hybrid circuit is disclosed which exhibits a different relative gain factor for transmitted signals and received signals. The difference in gain factors results in part from a combined balance circuit and transformer which exhibit a different coupling ratio between the primary and secondary coils on the receive path and the transmit path. The hybrid circuit may be used to isolate the receive signal from the transmit signal in the full duplex mode of operation. The gain from the transmit port to the receive port is minimum and most of the energy is transmitted to the subscriber line. In an embodiment of the invention a hybrid circuit for communicating a transmit signal and a receive signal across a subscriber line is disclosed. The hybrid circuit includes: a transformer and a balance circuit.

Abstract: A telephony system for conducting multimedia telephonic communications across a packet-based network is described between a caller system and an agent system through a software switch. The software switch receives from the caller system a packet representing a request to conduct a multimedia telephonic conference with an agent system. The switch exchanges packets with the caller system to establish a call with the caller system. The switch provides an application program interface to a telephony application program through which the telephony application program can control multimedia telephonic conferences between the caller and agent systems. The switch then processes the call according to the commands received through the application program interface from the telephony application program. In one embodiment, the application is an Automatic Call Distributor (ACD), which routes calls through the software switch.

Abstract: The current invention provides a method and apparatus for wireline characterization is disclosed. The method may be implemented with any modulation protocol but is particularly suited for multi-carrier modulation protocols such as discrete multi-tone (DMT). The apparatus may be incorporated into physical or logical modems. In an embodiment of the invention an apparatus for wireline characterization in a modem with a transmit path and a receive path each configured to couple with a remote modem via a wireline in which available communication bandwidth is split into a number of independent sub-channels is disclosed. The apparatus comprises: a tone selector, a cumulative loss estimator and a shift register. The tone selector selects a subset of the number of sub-channels within the bandwidth of a received wireline communication for which subset the sum of the square roots of the corresponding sub-channel indices may be expressed as an integer power “n” of 2.

Abstract: A method and apparatus for controlling a piezo-electric actuator coupled to a driven member is disclosed. The piezo-electric actuator is responsive to waveforms with asymmetrical voltage/current profiles on the rising and falling edge to effect consistent and cumulative movement of the driven member in one of two directions throughout the reciprocations of the piezo-electric actuator. The waveforms are digitally generated from a stored set of numbers or a function for generating the set of numbers. The numbers correspond with the discrete digital values associated with the desired waveforms for moving the driven member in either of at least two directions. The controller may be used to drive more than one piezo-electric actuator. The controller may include responsiveness to a feedback of the position of the driven member to accurately position the driven member.