Abstract: The event scheduler (100; 200) and method (300) of the present invention solve the problem of mixing multiple service categories on the same physical link or media by utilizing a calendar queue scheduling method (i.e., based on prior actual transmission times of previous packets). The event-driven cell scheduler is, for example used in an asynchronous transfer mode ATM network and may, for example, be embodied in software, hardware and firmware.

Abstract: The present invention provides an apparatus and method for adaptive entropy encoding/decoding in a multimedia compression system. For encoding, the steps include: A) parsing a predetermined number of quantized transform coefficients into a plurality of coefficient groups in a predetermined scanning order and converting the coefficient groups into a plurality of parameter sets according to a predetermined scheme and storing the parameter sets wherein, where a last coefficient group comprises all zero quantized transform coefficients, the last coefficient group is discarded; B) sending, in accordance with a signal from the encoder controller, a current parameter set of the plurality of parameter sets in the predetermined scanning order; C) adaptively selecting a current entropy encoder based on a state parameter of a last parameter set; D) encoding a current parameter set to provide entropy-encoded information bits. Decoding is accomplished in a fashion that mirrors the encoding method.

Abstract: A noise blanker (400) suitable for use with a radio receiver (500) having a track and hold unit (509) includes an impulse noise detector (401), a low pass filter (404) that is coupled to the impulse noise detector, and a first amplitude threshold detector (406) that is coupled to the output of the low pass filter and to the input of the track and hold unit. In one embodiment, this noise blanker is configured in conjunction with a radio receiver to yield a radio receiver that substantially minimizes the impact of noise impulses on resulting processed audio. In one embodiment, a second amplitude threshold detector (512) and a repetition rate threshold detector (513) are additionally utilized to allow gating of the internal signal processing paths of the radio receiver in conjunction with operation of the track and hold unit.

Abstract: The modem (300, 400) and method (700) of the present invention minimize the time required for the timing tracking system for phase lock loops in high speed modems, thus aiding systems that have short convergence periods in training. The present invention shortens the time for PLL convergence by initializing the PLL with values that approximate the actual timing frequency offsets.

Abstract: The present invention provides an apparatus and method for, in at least one of: encoding and decoding, scanning transform coefficients in an image/video encoded/decoder. In encoding, the steps include: A) segregating a predetermined number of quantized transform coefficients into a plurality of coefficient zones and storing the coefficient zones in a memory unit; B) examining each coefficient to determine which zone/zones has/have at least one non-zero coefficient; C) scanning each coefficient of the zones having at least one non-zero coefficient in a predetermined scanning order; D) encoding which coefficient zone contains at least one non-zero coefficient to provide first entropy-encoded information bits; E) determining whether at least one coefficient zone is to be encoded; F) encoding the non-zero coefficients to provide second entropy encoded information bits. Decoding is accomplished in mirror fashion.

Abstract: A method (1200, 1500, 1600, 1700, 1800) and packet switch (500, 600, 700, 1400,1900, 2000) for efficient switching of a plurality of received packets from a plurality of ingress ports to a plurality of egress ports, using the steps of: A) storing the packets in memory; B) sending arrival information for each packet to a destination egress port for the packet; C) storing, in memory at each destination egress port, the arrival information; D) requesting, by each destination egress port, the packets from the packet memory in accordance with a predetermined scheme; and E) sending, by the packet memory, to the destination egress ports, the packets requested.

Abstract: The present invention provides a method (200, 400) and device (500) for, within a variable or fixed block size video compression scheme, providing optimal bit allocation among at least three critical types of data: segmentation, motion vectors and prediction error, or DFD. Since the amount of information represented by one bit for a particular type of data is not equivalent to the information represented by one bit for some other data type, this consideration is taken into account to efficiently encode the video sequence. Thus, a computationally efficient method is provided for optimally encoding a given frame of a video sequence wherein, for a given bit budget the proposed encoding scheme leads to the smallest possible distortion and vice versa, for a given distortion, the proposed encoding scheme leads to the smallest possible rate.

Abstract: The present invention provides a manufacturing process (600) and method (500) for efficiently providing a multi-holographic optical element substrate unit. Upon preparation of an original continuous/non-continuous holographic optical element with uniform diffraction efficiency and marking the original continuous/non-continuous holographic optical element with predetermined alignment marks, the original continuous/non-continuous holographic optical element is cut into a predetermined number of individual holographic optical elements in accordance with the predetermined alignment marks. Then a substrate is prepared with alignment marks in accordance with the predetermined alignment marks of the individual holographic optical elements, and the individual holographic optical elements are attached to a substrate in accordance with the alignment marks.

Abstract: The present invention provides a method (200) and device (300) for error control of a video compressed sequence in which error protection for both random and burst channel errors is provided. The error control syntax (100) applies a fixed length packet synchronization system to variable length coded compressed video data, which provides the capability to limit error propagation within the decoded video bit stream. The fixed length packet control information provides information to decode compressed video data in both forward and reverse directions to allow for the recovery of correctly decoded video data within a decoded frame after long bursts of channel errors while reducing the overhead for error control. The error control method also provides video error detection which may be used for error concealment.

Abstract: A method (300) and communication system (400, 500, 600, 1300, 1400) provide a remote procedure call from a client to a server via an unreliable communication channel using a plurality of retransmission timers. The method includes transmitting, by the client to the server, a request and waiting for a confirm message and retransmitting, by the client to the server, the request after each of a predetermined sequence of time-out periods implemented by the plurality of retransmission timers until a confirm message is received.

Abstract: A method (900, 1000) and device (100, 600) are provided for encoding and/or decoding a compact representation of a discrete region contour for the purposes of image and video compression. The compact representation described provides bitstream scalability so that progressively larger subsets of the compact representation can be used to provide progressive better quality in the approximate reconstruction of the discrete region contours. The resulting device and method provide for coding of shape information within object-based and region-based image and video compression systems.

Abstract: The present invention provides a method (200) and an apparatus (100) for spatially adaptive filtering for video encoding. The apparatus filters a video sequence prior the encoding process. The apparatus comprises a noise variance determiner (102), a local variance determiner (104), a noise visibility function determiner (106), a Gaussian kernel determiner (108), and a convolver (110). The apparatus removes noise directly from a Displaced Frame Difference, DFD, signal. This novel approach removes noise and miscellaneous high frequency components from the DFD signal without the introduction of the filtering artifacts characteristic of current techniques. By reducing the miscellaneous high frequency components, the present invention is capable of reducing the amount of information that must be encoded by the video encoder without substantially degrading the decoded video sequence.

Abstract: A method (100, 200), device (300) and microprocessor (400) are provided for selectively compressing video frames of a motion compensated prediction-based video codec based on a predetermined set of compression techniques. An energy estimate of the current displaced frame difference, DFD, is used to compute a ratio between the estimate and a historical mean of energy estimates. The ratio is iteratively compared to a predetermined set of thresholds which are associated with the predetermined set of compression techniques. The comparisons are used to choose a technique based on the thresholds, and a technique is selected to be used for encoding the current DFD.

Abstract: Audio quality perception can be improved in an audio compression system 100 by defining a frequency subband threshold 205. With the frequency subband threshold 205, each frequency subband favorable to the threshold will be allocated at least a predetermined number of bits while frequency subbands unfavorable to the threshold will receive no bit allocations. This determination is made on an audio frame by audio frame basis, or upon change of the audio compression ratio, since changing any of the parameters: bitrate, sampling rate and coding mode changes the compression ratio.

Abstract: A complexity scalable device (100), method (300, 400) and digital video encoder (200) estimate a frame-to-frame motion vector of an image block of pixels to be encoded with adaptive threshold termination utilizing a novel dynamic threshold value determination. A dynamic threshold selector dynamically determines a threshold value in accordance with a predetermined scheme based on the quantization stepsize QP, and an adaptive motion vector determiner utilizes an original block, a reference frame, and the threshold value for adaptively estimating the frame-to-frame motion vector.

Abstract: A digital phase detector 100 receives a limited input signal 108 and inputs it and a reference oscillation 112 into an EXCLUSIVE NOR gate 102. The output 110 of the EXCLUSIVE NOR gate 102 is input to a gated N-bit counter 104, which produces an N-bit representation of the magnitude of the phase 115 of the signal 108. A sign detector 105 determines the sign of the phase of the signal by sampling the resultant 110 and combines the magnitude of the phase 115 with the sign of the phase to produce a digital numeric representation of the phase of the signal 116.

Abstract: The invention prevents an operating system from freezing operation of computer peripherals such as a PCMCIA modem card constructed using an AT&T HSM PID2 Chipset when a suspend mode is activated by the computer. The invention provides a simulation (device: 100, 200; method: 300, 600, 700) of an idle Universal Asynchronous Receiver Transmitter, UART, in a computer peripheral operably coupled to the computer wherein the simulation provides a logic one in a least significant bit position for the PCMCIA data bus, thereby indicating that no data remains to be sent on the PCMCIA data bus.

Abstract: The present invention provides a method (400) and antenna (100) for providing an omnidirectional pattern. The antenna (100) is smaller than prior art omnidirectional antennas with the same bandwidth. The smaller size is made possible by the use of at least one capacitive element (104) at a discontinuity in the loop (102). The pattern is balanced and therefore the omnidirectionality is maintained by the current maximum (110 and 112) that are created by the capacitive element (104).

Abstract: Shared bandwidth is allocated among a plurality of users of a communications system of the type in which information is communicated in a sequentially repeating series of frames of information, each frame being subdivided into a number of slots, and each slot being capable of carrying a quantity of information. The bandwidth is allocated by determining the number of slots available in a frame for a predetermined group of users, determining the number of slots requested by each user of the group, and allocating slots in the frame to predetermined ones of the users of the group in accordance with a predetermined allocation scheme.

Abstract: A data communication system that includes a subscriber unit operating at a transmission data rate encompasses a method of transmitting an information stream. This method includes the steps of determining the transmission data rate, determining a partitioning factor based at least in part on the transmission data rate, gathering constituent elements of the information stream, and using the partitioning factor to packetize the constituent elements of the information stream for transmission thereof.