254results about How to "Low bandwidth" patented technology

The present invention relates to a communication system comprising a plurality of terminals each having an uplink transmission unit (1) for transmitting radio frequency OFDM signals at a radio frequency and an access point having an uplink receiving unit (4) for concurrently receiving said radio frequency OFDM signals from at least two terminals, said OFDM signals being Orthogonal Frequency Division Multiplex (OFDM) modulated, wherein the bandwidth of said uplink transmission units and of the transmitted radio frequency OFDM signals is smaller than the bandwidth of said uplink receiving unit, that the bandwidth of at least two uplink transmission units and of their transmitted radio frequency OFDM signals is different and that the uplink transmission unit is adapted to assign different connections for concurrently transmitting radio frequency OFDM signals to different sub-carriers in the same time slots or to the same or different sub-carriers in different time slots.

Route selection through a wireless mesh network between a source node and a destination node is based on minimizing generated interference in order to increase the capacity of the network. An interference energy associated with transmitting a packet over each hop in multiple routes from the source node to the destination node is determined. The interference energy for each hop is combined to generate a combined interference energy for each route. One of the routes is selected based on the combined interference energy determined for each route.

The invention increases performance of HTTP over long-latency links by pre-fetching objects concurrently via aggregated and flow-controlled channels. An agent and gateway together assist a Web browser in fetching HTTP contents faster from Internet Web sites over long-latency data links. The gateway and the agent coordinate the fetching of selective embedded objects in such a way that an object is ready and available on a host platform before the resident browser requires it. The seemingly instantaneous availability of objects to a browser enables it to complete processing the object to request the next object without much wait. Without this instantaneous availability of an embedded object, a browser waits for its request and the corresponding response to traverse a long delay link.

A system for transporting a high speed data stream over a plurality of relatively low bandwidth unshielded twisted copper pairs within the local loop plant or in any environment having a plurality of copper lines, such as on campuses, within large buildings, etc. The copper twisted pairs are transformed from a plurality of low bandwidth, low reliability links into a high reliability, very high bandwidth long range communication channel utilizing optimized xDSL transmission technologies over the plurality of copper pairs. A transmit data processor perform scrambling, FEC encoding and interleaving on the data before it is divided and dispatched to the plurality of modem elements for transmission over the local loop plant, either bidirectionally or unidirectionally. On the receiving side, the individual data streams are collected, aggregated and a receive data processor performs de-interleaving, FEC decoding and de-interleaving, resulting in the high speed data stream originally transmitted. The system also includes means for increasing the performance of the xDSL modem elements including crosstalk cancellation, power and PSD control, data rate control and optimal routing of the transmitted signals within the twisted pair binders. Network elements located remotely on the other side of the plurality of copper pairs are provided electrical power. In addition, the system optionally multiplexes a plurality of low bandwidth telephony services over the high speed link using either TDM or FDM techniques.

A system and process for broadcast and communication with bi-level or sketch video at extremely low bandwidths is described. Essentially, bi-level and sketch video presents the outlines of the objects in a scene being depicted. Bi-level and sketch video provides a clearer shape, smoother motion, shorter initial latency and cheaper computational cost than do conventional DCT-based video compression methods. This is accomplished by converting each color or gray-scale image frame to bi-level or sketch image frame using adaptive thresholding method, compressing bi-level or sketch image frames into bi-level or sketch video using adaptive context-based arithmetic coding method. Bi-level or sketch video is particularly suitable to such small devices as Pocket PCs and mobile phones that possess small display screen, low bandwidth connection, and light computational power.

An array stimulator has a plurality of electrodes in an array (22), the electrodes forming a plurality of electrode pairs, and a signal generator (18) for generating signals to the electrodes so as to generate electrical pulse in a patient to which the stimulator has been applied either transcutaneously or by implantation. Those electrical pulses form a composite pulse in the patient which stimulates the nervous system of the patient. The composite pulse has a duration between 4 μs and 1500 μs and a maximum voltage between 2V and 50V when the stimulator is implanted, and 15V to 500V when applied transcutaneously. The electrical pulses themselves are significantly shorter duration than the composite pulse, so they stimulate the nervous system of the patient much less than the composite pulse or not at all.

In a broadcast application on a client-server network the streaming is emulated of animation data over the Internet to a large number of clients. The animation is considered a sequence of states. State information is sent to the clients instead of the graphics data itself. The clients generate the animation data itself under control of the state information. The server and clients communicate using a shared object protocol. Thus, streaming is accomplished as well as a broadcast without running into severe network bandwidth problems. This approach is used to map a real life event, e.g., a motor race, onto a virtual environment in order to let the user participate in a virtual race against the real life professionals, the dynamics of the virtual environment being determined by the state changes sent to the user.

In a broadcast application on a client-server network the streaming is emulated of animation data over the Internet to a large number of clients. The animation is considered a sequence of states. State information is sent to the clients instead of the graphics data itself. The clients generate the animation data itself under control of the state information. The server and clients communicate using a shared object protocol. Thus, streaming is accomplished as well as a broadcast without running into severe network bandwidth problems. This approach is used to map a real life event, e.g., a motor race, onto a virtual environment in order to let the user participate in a virtual race against the real life professionals, the dynamics of the virtual environment being determined by the state changes sent to the user.

A digital predistortion amplifier design compensates for non-linear amplification of an input signal using predistortion techniques. The design provides a reduced noise floor by using separate digital to analog converters (DAC) to separately convert the input signal and an error correction signal. Furthermore, the input signal can be separated into two or more subbands of narrower bandwidth. Each of the subbands are converted to analog using a separate DAC. By reducing the power and / or bandwidth to be handled by any one DAC, the available levels of quantization of the DAC are applied to a lower power signal and therefore the signal to noise ratio resulting from the conversion process is improved. In addition, each digital subband is passed through a correction filter, which is driven by an adaptive control processing and compensation estimator to compensate for relative gain, phase, and delay inconsistencies between the different subbands.

Part of the spectrum of two or more input signals is encoded using conventional coding techniques, while encoding the rest of the spectrum using binaural cue coding (BCC). In BCC coding, spectral components of the input signals are downmixed and BCC parameters (e.g., inter-channel level and / or time differences) are generated. In a stereo implementation, after converting the left and right channels to the frequency domain, pairs of left- and right-channel spectral components are downmixed to mono. The mono components are then converted back to the time domain, along with those left- and right-channel spectral components that were not downmixed, to form hybrid stereo signals, which can then be encoded using conventional coding techniques. For playback, the encoded bitstream is decoded using conventional decoding techniques. BCC synthesis techniques may then apply the BCC parameters to synthesize an auditory scene based on the mono components as well as the unmixed stereo components.

The present invention relates to a communication system comprising a plurality of terminals each having an uplink transmission unit (1) for transmitting radio frequency OFDM signals at a radio frequency and an access point having an uplink receiving unit (4) for concurrently receiving said radio frequency OFDM signals from at least two terminals, said OFDM signals being Orthogonal Frequency Division Multiplex (OFDM) modulated, wherein the bandwidth of said uplink transmission units and of the transmitted radio frequency OFDM signals is smaller than the bandwidth of said uplink receiving unit and that the bandwidth of at least two uplink transmission units and of their transmitted radio frequency OFDM signals is different. The present invention relates further to a communication system wherein the access point has a downlink transmission unit (7) for transmitting radio frequency OFDM signals at a radio frequency and that the at least two terminals each have a downlink receiving unit (11) for receiving said radio frequency OFDM signals, wherein the bandwidth of said downlink transmission unit is larger than the bandwidth of said downlink receiving units and that the downlink transmission unit is adapted to generate and transmit radio frequency OFDM signals having a bandwidth that is smaller than or equal to the bandwidth of the downlink transmission unit and that is equal to the bandwidth of the downlink receiving unit by which the radio frequency OFDM signals shall be received. Still further, the present invention relates to a communication method, to a terminal and to an access point for use in such a communication system.

In one aspect the invention relates to a method of associating an element of a user-interface to a current state of a property in a system including an application having a plurality of components, wherein at least one component has a property, wherein each property is identified with an identifier. The method comprises associating the element of the user-interface with a property path, the property path including a concatenation of a plurality of identifiers, the concatenation of identifiers defining a path through the components of the application to a property at the end of the concatenation, and mapping the property path to a current state of the property at the end of the path defined by the concatenation of identifiers, to associate the element of the user-interface with the current state of that property.

On a BD-ROM, there is recorded is a digital stream into which video and audio streams are multiplexed. The video stream is composed of a plurality of pictures that together represent video. The graphics stream includes a PES packet storing state control information (ICS) and PES packets containing graphics data (ODSs). The graphics data constructs an interactive display. The state control information defines the control so as to change the states of buttons presented on the interactive display according to the reproduction proceeding and user operations. The ICS is attached with a PTS showing the display timing of a picture to be synchronized with the interactive display. The ODS is attached with a PTS showing the timing for decoding the graphics data. The timing shown in the ODS is prior to the display timing.

A system and process for broadcast and communication with bi-level or sketch video at extremely low bandwidths is described. Essentially, bi-level and sketch video presents the outlines of the objects in a scene being depicted. Bi-level and sketch video provides a clearer shape, smoother motion, shorter initial latency and cheaper computational cost than do conventional DCT-based video compression methods. This is accomplished by converting each color or gray-scale image frame to bi-level or sketch image frame using adaptive thresholding method, compressing bi-level or sketch image frames into bi-level or sketch video using adaptive context-based arithmetic coding method. Bi-level or sketch video is particularly suitable to such small devices as Pocket PCs and mobile phones that possess small display screen, low bandwidth connection, and light computational power.

The invention increases performance of HTTP over long-latency links by pre-fetching objects concurrently via aggregated and flow-controlled channels. An agent and gateway together assist a Web browser in fetching HTTP contents faster from Internet Web sites over long-latency data links. The gateway and the agent coordinate the fetching of selective embedded objects in such a way that an object is ready and available on a host platform before the resident browser requires it. The seemingly instantaneous availability of objects to a browser enables it to complete processing the object to request the next object without much wait. Without this instantaneous availability of an embedded object, a browser waits for its request and the corresponding response to traverse a long delay link.

A system and method provides an electronic content to a vehicle from access point(s) within a network using a controller. The controller divides the electronic content into one or more files wherein each file contains at least one packet, and generates two or more random linear combinations of the packets within each file. For each file, each random linear combination of the packets is replicated to a different access point within the network. The electronic content is provided to the vehicle using at least one of the different access points. The controller can also determine a set of nearest trajectories for the vehicle in a location database that match a recent location history for the vehicle. For each determined nearest trajectory, one or more mobility trajectories are determined for the vehicle, and a set of access points are determined that correspond to the determined mobility trajectories for the vehicle.

Disclosed are systems and methods which provide high bandwidth data communication with respect to a large coverage area using smart antenna and / or directional antenna techniques. Embodiments provide extended wireless local area network (WLAN) coverage areas using a directional antenna, with the cooperation of a cellular system or proprietary WLAN infrastructure to perform best antenna beam pattern estimation and signaling. Stations disposed beyond a WLAN coverage area may establish contact and exchange signaling information with an access point through a secondary control channel. Such a secondary control channel signaling may be relatively low bandwidth and may be utilized to identify the need to communicate data, to identify a “best” directional antenna beam through which to communicate data, etcetera. Payload data may then be transmitted at a high bit rate through one or more smart antenna beams targeted at the appropriate stations.

The present invention employs hierarchical modulation to simultaneously transmit data over different modulation layers using a carrier RF signal. Each modulation layer may be of a higher or lower order than the other modulation layers. Certain embodiments of the present invention may transmit different information on the different modulation layers. Other embodiments of the present invention may use the different layers for processing different information streams.

A memory system is provided that increases the overall bandwidth of a memory channel by operating the memory channel at a independent frequency. The memory system comprises a memory hub device integrated in a memory module. The memory hub device comprises a command queue that receives a memory access command from an external memory controller via a memory channel at a first operating frequency. The memory system also comprises a memory hub controller integrated in the memory hub device. The memory hub controller reads the memory access command from the command queue at a second operating frequency. By receiving the memory access command at the first operating frequency and reading the memory access command at the second operating frequency an asynchronous boundary is implemented. Using the asynchronous boundary, the memory channel operates at a maximum designed operating bandwidth, which is independent of the second operating frequency.

A scalable Media-on-Demand (MoD) method to a large group of users in the Internet. This method makes use of peer buffering capabilities to collaborate in the distribution and downloading of media, facilitated by a central repository for the search of optimal peers as parent nodes to connect to and for the support of advanced features such as fast forward and backward plays. The method relieves the server load by shifting the media streaming functionality to the client side with high media receiving continuity and quality, leading to well-balanced and low network loads.

Content resources are managed. A request is received from a user for access to a source of content resources. It is determined that the user is authorized for access to the source. A portal Web page is generated based on a set of content element data applicable to the subscriber. The portal Web page is returned to the user. A system for use in managing content resources has a switch for receiving requests from Web browsers, a content resource management engine in communication with the switch, and a billing system in communication with the content resource management engine.

A system and method for using magnetic resonance to track a medical device which attenuates interfering MR signals. The system comprises an MR tracking device comprising one or more radiofrequency (RF) tracking coils adapted to receive a magnetic resonance MR response signal from nuclei excited by an RF pulse. Ideally, the RF tracking coil only receives an MR response signal from nuclei in matter in the close vicinity of the tracking device. The tracking device is attached to medical device. The interfering signal tends to emanate from large objects or large volumes that are outside the close vicinity of the tracking device but which are still weakly coupled to the tracking device. A dephasing gradient is applied perpendicular to the readout gradient before the RF response signal is received thereby dephasing the interfering signal emanating from remote nuclei, which strongly attenuates the interfering signal while the MR response signal is substantially unaffected. The system can also detect errors in tracking location by checking the amplitude of the signal from each coil and the detected distance between each coil, and correcting for such errors by ignoring data from coils having low amplitude or location deviating from known location relative to the other coils.

An optoelectronic distance measuring device is disclosed. The device has a transmitting unit with a driver stage for emitting optical pulses, a receiving unit for receiving a portion of the optical pulses, said portion being reflected from a target object, and converting it into an electrical reception signal, via a photosensitive electrical component. It also has an analog-digital converter for digitizing the reception signal, and an electronic evaluation unit to ascertain a distance from the target object on the basis of a signal propagation time using the digitized reception signal. The driver stage can be designed so that at least two pulse durations of different length for the optical pulses can be set.

A memory system is provided that reduces latency by running a memory channel fully asynchronous from a memory device frequency. The memory system comprises a memory hub device integrated in a memory module. The memory hub device comprises a command queue that receives a memory access command from an external memory controller via a memory channel at a first operating frequency. The memory system also comprises a memory hub controller integrated in the memory hub device. The memory hub controller reads the memory access command from the command queue at a second operating frequency. By receiving the memory access command at the first operating frequency and reading the memory access command at the second operating frequency an asynchronous boundary is implemented. The first operating frequency is a maximum designed operating frequency of the memory channel and the first operating frequency is independent of the second operating frequency.

A method and apparatus for controlling and providing force feedback using an interface device manipulated by a user. A microprocessor is provided local to the interface device and reads sensor data from sensors that describes the position and / or other information about an object grasped and moved by the user, such as a joystick. The microprocessor provides the sensor data to a host computer that is coupled to the interface device by a communication bus that preferably includes a serial interface. In a “host-controlled” embodiment, the host computer calculates force values using the sensor data and other parameters of a host application program and sends the force values to the local microprocessor, which directly provides the force values to actuators to apply forces to the user object. In a “reflex” embodiment, the host computer sends high level supervisory commands to the local microprocessor, and the microprocessor independently implements a local process based on the high level command for reading sensor data and providing force values to the actuators using sensor data and other parameters.

A television system for presenting interactive television services to a user. The system comprises a local memory in which one or more data parameters are stored. The system is operable to determine the availability of data from a data source, and capture a first portion of the available data and store it in a first area of the local memory. The system uses the parameters stored in the local memory to determine whether the first data portion references a second portion of the available data. In the event that it does, the second portion of the data is captured and also stored in the first area of local memory. The first and second portions of data are processed according to their identities. The processed data is written to a second area of the local memory, so that it can be used to present interactive television services to the user.

Content resources are managed. A request is received from a user for access to a source of content resources. It is determined that the user is authorized for access to the source. A portal Web page is generated based on a set of content element data applicable to the subscriber. The portal Web page is returned to the user. A system for use in managing content resources has a switch for receiving requests from Web browsers, a content resource management engine in communication with the switch, and a billing system in communication with the content resource management engine.

An ophthalmic instrument (for obtaining high resolution, wide field of area multi-spectral retinal images) including a fundus retinal imager, (which includes optics for illuminating and imaging the retina of the eye); apparatus for generating a reference beam coupled to the fundus optics to form a reference area on the retina; a wavefront sensor optically coupled to the fundus optics for measuring the wavefront produced by optical aberrations within the eye and the imager optics; wavefront compensation optics coupled to the fundus optics for correcting large, low order aberrations in the wavefront; a high resolution detector optically coupled to the imager optics and the wavefront compensation optics; and a computer (which is connected to the wavefront sensor, the wavefront compensation optics, and the high resolution camera) including an algorithm for correcting, small, high order aberrations on the wavefront and residual low order aberrations.

A method and apparatus for controlling and providing force feedback using an interface device manipulated by a user. A microprocessor is provided local to the interface device and reads sensor data from sensors that describes the position and / or other information about a user object moved by the user, such as a joystick. The microprocessor controls actuators to provide forces on the user object and provides the sensor data to a host computer that is coupled to the interface device. The host computer sends high level host commands to the local microprocessor, and the microprocessor independently implements a local reflex process based on the high level command to provide force values to the actuators using sensor data and other parameters. A provided host command protocol includes a variety of different types of host commands and associated command parameters. By providing a relatively small set of high level host commands and parameters which are translated into a panoply of forces, the protocol further shifts the computational burden from the host computer to the local microprocessor and allows a software developer to easily create force feedback applications.