Koninklijke Philips Corporation N.v.

Other

Zhun Zhong

Yingwei Chen

Amjad Ali Soomro

Tse-Hua Lan

Javier Del Prado Pavon

Shaomin Peng

Stefan Mangold

Kiran Srinivas Challapali

Sai Shankar Nandagopalan

Guido Roland Hiertz

Atul Garg

Joerg Habetha

Cornelis Van Zon

Sai Shankar

Marc Portoles

Wireless networks and their method of implementation include a first network and one or more networks. The first network assigns designated time slots to each of the one or more networks during which at least one device of at least one of the networks may communicate with at least one other device of its respective network.

Method to achieve coexistence between centralized TDMA MAC and a second MAC in wireless communication systems

In order to reduce the average wait time, information regarding regulatory domain, a component of channel availability, may be obtained through an apparatus and method for transmitting within available channels in a wireless network. This includes determining available channels in a wireless network by: receiving regulatory domain information within the wireless network; generating a frame with at least one component corresponding to the regulatory domain information; transmitting the frame unsolicited by a beacon; receiving the report at a station; and determining whether a channel is available for transmission based, at least in part, on the component corresponding to the regulatory domain information contained in the frame.

Enhanced site report by low latency roaming by passive scanning in IEEE 802.11 networks

A wireless local area network (WLAN) includes at least one hybrid coordinator (HC) and at least one Quality of Service Station (QSTA). The HC transmits a schedule frame element (SEF). The WLAN also includes a clocking mechanism that sets a substantially absolute start time of a service interval. A method of synchronizing the HC and the QSTA includes transmitting a schedule element frame (SEF), and setting a substantially absolute start-time of a service interval, and a first transmitted frame element.

Method for scheduling service periods in a wireless local area network (WLAN)

A wireless network () includes a plurality of wireless stations (QSTAs) () and an access point (QAP) (). The QAP, or one or more of the QSTAs, or both, are adapted to measure delay data, or queue data, or both, per one or more traffic type. A method of wireless communication is also described.

Measuring and monitoring QoS in service differentiated wireless networks

The present invention relates to specification of the start time for taking measurements in wireless local area networks (WLAN), in which the start time of measurements to be taken is included in a Measurement Start Time field of a Measurement Request Frame and the interpretation of the start time for a specific measured element is determined by a Mode field included in each Measurement Request Element field of the Measurement Request Frame. Optionally, the start time of a Measurement Request Frame is specified using a time synchronization function (TSF) timer value or part thereof in order to avoid ambiguities in interpretation of the start time reported.

System and method for specifying measurement request start time

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.

Beaconing protocol for ad-hoc networks

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.

Power management in an IEEE 802.11 IBSS using an end of ATIM frame and a dynamically determined ATIM period

An apparatus and method is provided for measuring medium activity patterns in wireless networks and deriving information about the radio environment from the measured medium activity/patterns. This invention is three-fold. First, it defines what to measure, including medium idle/busy patterns based on power detection, medium idle/busy pattern based on preamble detection, and medium idle/busy pattern based on virtual sensing. Second, it provides a mechanism for communicating the measurement request and report, as illustration for the case of IEE 802.11. And last, it defines the information that can be derived given these measurements as discovery of: non-802 devices, 802.11e systems, 802.11e contention-based medium access priorities, 802.11e controlled medium access usage, 802.11b/g existence, and hidden stations.

Measuring medium activity patterns in wireless networks and deriving information from the activity patterns

A plurality of methods, computer program product, and apparatus that use a lower 32 bit field of a 64-bit 802.11 TSF timer, so as to encode the reference time instant without the ambiguity as to whether there the reference time is referring to a future time or a past time. According to an aspect of the present invention, the fact that the low order 32 bits of the TSF timer wraps over in about 71 minutes is exploited to remove any ambiguity in the reference times contained in the Schedule Element frame. One method employs an algorithm base on distance between two reference points to determine whether the timer has wrapped around a time period, and another method uses a delay interval or a timeout to determine whether or not the TSF timer is wrapped or unwrapped. Another method includes determining whether an absolute value of X&#x2212;O is less than, or greater than or equal to maximum value M/2.

Methods to resolve TSF timer ambiguity of IEEE 802.11e schedule element

In a wireless local area network (WLAN), the present invention provides a system and method for identifying traffic suffering from bad link quality and dynamically adjusting channel access to restrict the effect of this bad link quality. The dynamic adjustment to channel access is accomplished by lowering or raising the limit on the number of packets that can be transmitted between an AP and the wireless station over the a link as determined by the link quality. The link quality is determined by tracking the number of successive packet transmission successes and errors.

System and method for an IEEE 802.11 access point to prevent traffic suffering bad link quality from affecting other traffic

The present invention is directed to reduced B-frame decoding. According to the present invention, the number of transform coefficients in B-frames are reduced to produce reduced B-frames. Also, inverse scanning and inverse quantization is performed on the reduced B-frames. Further, an inverse transform is performed on the reduced B-frames. In one embodiment of the present invention, the reduced B-frames are produced by identifying blocks associated with the B-frames and selecting transform coefficients included in a predetermined area of the identified blocks.

Reduced complexity video decoding by reducing the IDCT computation in B-frames

Data compressed according to a lossy DCT-based algorithm, such as the MPEG or MPEG2 algorithms, is decompressed according to a dynamically-selected set of DCT coefficients, with unused coefficients masked out. A macroblock of the data exhibiting little motion is decompressed with a small subset of DCT coefficients, while a macroblock exhibiting more motion is decompressed using a larger subset of DCT coefficients up the full set of DCT coefficients. Average computational complexity is thus kept low, enabling the use of inexpensive equipment, while degradation is minimized.

Reduced complexity IDCT decoding with graceful degradation

A system and method that reduces computational complexity of a decoder by identifying a skippable region in an overlaid area. The invention provides a system for processing encoded video data, comprising: an analysis system that determines if a current video frame having an overlaid area acts as a reference for future video frames; and a system for identifying a skippable region in the overlaid area. The invention may also include a system for identifying a portion of the overlaid area as the skippable based on analysis of motion vectors or motion vector ranges.

Method and system for skipping decoding of overlaid areas of video

A method and system of reducing the computation load of an MPEG decoder by changing the encoding algorithms in a video-processing system are provided. During an encoding mode, a stream of data blocks is received and at least one motion vector and one motion compensation prediction value for each macro-block are generated. The prediction value is transformed into a set of DCT coefficients. Prior to the quantizing step, the set of DCT coefficients are modified according to predetermined criteria. To this end, the total energy level of the DCT coefficients excluding the lowest 2&#xd7;2 DCT coefficients is computed, and last column and last row of the DCT coefficients is discarded alternatively until the total energy level of the DCT coefficients reaches a predetermined energy level. Therafter, the discarded column or row is assigned to a predetermined value. The modified DCT coefficients are then quantized and encoded, thereby generating a bit stream of encoded macro-blocks, which are subsequently decoded according to a conventional decoding process.

System and method for providing a single-layer video encoded bitstreams suitable for reduced-complexity decoding

A video processing system comprising: a decoder having a complexity reduction system; and a post-processing system for processing an output of the decoder, wherein the post-processing system includes a filter for intentionally blurring a set of frames in a group of pictures (GOP) to achieve a smooth visual transition between frames.

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Croton-on-Hudson, NY, United States of America

Zhun Zhong