Abstract: The present invention relates to a method for performing fast channel switching in a wireless local area network (WLAN). The method generally includes the steps of: determining that the wireless medium has been idle during a PCF interframe space (PIFS) period, transmitting a first management frame during a slot time following the PIFS period; wherein the transmission at said slot time substantially guarantees priority access said wireless medium; and performing fast channel switching in the network in accordance with directives contained within the management frame. Fast channel switching as defined herein includes one of quieting the current channel and/or switching from a current channel of operation to a new channel of operation. The method overcomes the latencies associated with contention based services, such as the DCF service.

Abstract: The present invention relates to a display device with a birefringent lens system having cylindrical lenses, extending in a main direction. The polarization of light modulated by a LC layer is twisted by a rotator layer (25?) in order to be perpendicular or parallel with this main direction. A birefringent compensation layer (26) is used to remove any ellipticity introduced by the rotator layer (25?). This provides improved contrast when the display device is used e.g. in a switchable 2D/3D display.

Abstract: A wireless system (100) and method (401-403) includes a medium access control (MAC) layer adapted to request and receive measurement reports from wireless devices (102) operating in restricted channels.

Abstract: A distributed MAC protocol that includes a super-frame having a slotted Beaconing Period and a data transfer period. The super-frame includes a plurality of medium access slots which are assigned to the slotted Beaconing Period. The Beaconing Period length may be fixed or variable. The Beaconing protocol defines initializing an ad hoc network by means of starting a Beaconing Period, joining an existing Beaconing Period of ad hoc network and resolving collisions during the Beaconing Period.

Abstract: A system and method for a simplified Maximum Likelihood (ML) decoding (203) for MIMO systems is provided. The full ML decoding gives the lower bound of the decoding for CC coded MIMO systems. However, the computation cost is too high to be implemented in real system. Many alternative methods have been proposed for the decoding. Among them, weighted Zero Forcing (WZF) is one that can give affordable performance with reasonable computation complexity but there are several dB of performance gap for the WZF decoding and ML decoding. This present invention discloses a decoding system and method having improved performance over WZF decoding with affordable implementation complexity.

Abstract: An optical system or front end for adding an optical depth information to a two-dimensional image (1), wherein the optical system includes an array of optical lenses (2) arranged in front of the two-dimensional image (1). The optical lenses have adjustable focal length (strength) in response to the optical depth information (D). An optical barrier (3) is arranged in front of the array of optical lenses (2) with optical apertures aligned with the optical lenses of the array of optical lenses (2). Such optical front end can be used for 3D displays based on known 2D displays including LCD, LCOS, Plasma, and CRT type displays. Such a 3D display does not suffer from a resolution loss depending on a number of viewing angles. In embodiments adapted for pixelized 2D displays, the array of optical lenses preferably has one lens per pixel. The barrier (3) may be fixed or adjustable to allow adjustment of the characteristics of the added optical depth.

Abstract: An improved moving particle display device having a plurality of pixels (12, 14; 21, 22, 23, 24) is disclosed. The pixels are formed between first (1) and second (2) substrates that are spaced apart by a plurality of partition walls (10; 20). Each pixel comprises charged particles (115) that are movable under the influence of primary electric field lines of force (16) to set the optical appearance of the pixel. The pixels further comprise blocking material (210) for physically blocking the charged particles from entering predetermined regions (200) of the pixels that are likely to have secondary electric field lines of force (18) that extend through the partition walls. Hence, the charged particles are blocked from entering regions of the pixels having secondary electric field lines of force that could attract the particles to move into any gaps (9) that exist between the partition walls and the substrates.

Abstract: A display apparatus comprising a display device (104, 200, 301, 401) configured to display an image is disclosed. The display device comprises a plurality of picture elements, and one or more lenticular means (203). The lenticular means comprises one or more refracting layers (303, 403) configured to direct light emanating from said picture elements in a plurality of directions such that said image of a picture element is divided in two or more essentially identical images.

Abstract: An optical system that can add an optical depth information to a two-dimensional image (72) represented by substantially collimated light, e.g. by using a collimated light source in front of a LCD display. The optical system includes a first array of optical lenses (70) arranged at a first distance in front of the two-dimensional image (72), and a second array of optical lenses (71) arranged at a second distance in front of the two-dimensional image (72), the second distance being larger than the first distance. Optical properties, e.g. focal length, can be adjusted for the optical lenses of the first and second array of optical lenses (70, 71) in response to the optical depth information. The optical system can serve as an optical front for 3D multiview displays. Depending on embodiment, both horizontal and vertical angular resolution can be obtained, and the front end exhibits only a small brightness loss.

Abstract: A SIMD processor architecture (2) for processing a stream of data vectors is provided, the architecture comprising a processor array (4) comprising a plurality of processors (PE(0), . . . , (PE(N)), each processor ((PE(0), . . . PE(N)) being adapted to process a data element in each vector, the operation of the processor array (4) being controlled by a local clock signal having a first frequency; a control processor (16) adapted to control the operation of the SIMD processor architecture (2) and generate signals to synchronize the operation of the processor array (4) with the stream of data vectors, the operation of the control processor (16) being controlled by a local clock signal having a second frequency; and power management means (30) for adjusting the frequencies of the local clock signals in response to the synchronization signals generated by the control processor (16), thereby minimizing the power consumption of the SIMD processor architecture (2).

Abstract: The system and method of the present invention provide a protocol for a device (400) to announce that a previously reserved time-period or time-slot is not (completely) used and becomes available, so that other devices can transmit during the unused time. The system and method are especially intended for systems with distributed medium reservation by the devices, i.e., those systems adhering to a distributed reservation protocol (DRP).

Abstract: A method and system for efficiently utilizing frequency spectrum resources is disclosed. The method comprises the steps of determining at least one spectrum opportunity (510), wherein the opportunity is identified by a frequency range and a time duration, determining a set of altered transmission characteristics (515, 517) to allow transmission of a desired signal in the identified frequency range, wherein the altered transmission characteristics avoid interference with signals expected in the frequency range, and transmitting said desired signal using the altered transmission characteristics when the transmission occurs during said time duration. In one aspect of the system, the step of determining at least one opportunity comprises the steps of receiving signals in known frequency ranges, and determining the characteristics of the received signals.

Abstract: A wireless activation system, such as a keyless car entry system, uses repeated code sequences for communication between a transmitter device and a receiver device. By varying the sequence duration in a synchronism at the transmitter device and receiver device, either by varying the number of symbols or chips in the sequence, or by varying the symbol or chip rate, it is made more difficult for an unauthorised party to detect the code sequences and relay the code sequences to achieve unauthorised activation at the receive device.

Abstract: A plurality of methods, apparatus and computer program for providing warning to a station (STA) associated with an Access Point (AP) in a WLAN that a disassociation the AP is imminent. The steps include (a) selecting a station (STA) for disassociation from a particular Access Point (AP) of a WLAN; (b) by updating a newly created reason code field of a message to indicate to the selected STA that it has become a candidate for disassociation; and (c) transmitting the message to the selected STA. Upon receipt by the STA of a message indicating that the selected STA has become a candidate for disassociation, the selected station scans other Access Points from a list to find another Access Point to associate with before being cut off by the current Access Point.

Abstract: Disclosed is a method and system based on MAC frames for enabling a QAP to seamlessly operate between granting polls for upstream and sidestream traffic while sending downstream frames. The inventive scheduling method uses a minimum set of mandatory TSPEC parameters to generate a schedule, which provides minimum performance requirement in wireless local area networks (WLANs).

Abstract: A consumer apparatus is made an intuitive component of a user-interface to a topical server. A specific user-interaction with the apparatus or its proxy on the home network causes a request to be sent to a specific server on the Internet based on a predefined URL. The home network receives a particular web page from the server with content information dedicated to the context of use of the apparatus.

Abstract: A channel quieting/measurement request element is provided for use in a wireless local area network. The unified element of the invention integrates a dual capability for performing channel quieting and for making measurement requests of one or more stations in the network. According to another aspect of the invention, a conventional channel quieting element is modified to include provisions for defining an offset time and an offset duration interval for performing channel quieting.

Abstract: Watermark detectors have a buffer in which a number of image tiles are folded and accumulated prior to computing the correlation between buffer contents and the watermark pattern being looked for. The intention of the folding and accumulation process is to average out the video content while accumulating the embedded watermark energy. This no longer appears to hold for strongly compressed video, such as DIVX, which exhibits a lot of artificial noise and undesired similarity (block patterns). As a result thereof, correlation peaks are often below the threshold. In a similar manner, the compression affects scale detection. According to this invention, only frames (or parts thereof) that are not so heavily compressed and therefore have a high probability of carrying enough watermark energy are folded and accumulated. To this end, a quality metric is calculated, the quality metric being indicative of the degree of compression of the data.

Abstract: An apparatus and method is provided for power management in an Independent Basic Service Set (IBSS) Wireless Local Area Network (WLAN) that replaces the Ad-hoc Traffic Indication Message (ATIM) and its associated control logic, with a protocol comprising a variable length Data Alert frame transmission period or Data Alert window that accommodates the traffic in the IBSS and is followed by a data frame transmission period, a special End of Alert frame, a special LIFS for the End of Alert frame and new control logic. The End of Alert frame has a lower priority in a contention for a medium with a Data Alert frame, i.e., the Data Alert frame has the equivalent of a higher priority, thereby maximizing the number of Data Alerts sent during any Data Alert window. This approach to power management achieves optimal allocation of time used to send Data Alert frame and data frame thus minimizes power consumption by all wireless stations of the IBSS.

Abstract: The invention relates to light emitting devices (2) with variable output color. More specifically, the inventions provides a color conversion cell (10) which can be positioned in front of a light source (4) in order to generate other color or color temperatures. Typically the light source is a light emitting diode (LED) which is power efficient but emits in a narrow and fixed spectra. The new colors are generated by photoluminescence in fluorescent dyes contained in the cell. The color converting of the cell is electrically controllable, preferably by controlling the orientation, density or distribution of the fluorescent dyes, or by controlling a pathlength of the light in the cell.