Abstract: A medium-reservation mechanism improves transmission efficiency in a multiple-channel network that includes stations with limited-selectivity receivers. The mechanism employs a medium-request signal that conveys channel information. In this network, stations check the channel information in the medium-request signal to decide whether or not to comply with the medium-request signal. If the channel information identifies the channel that is close to the channel that the station is presently operating on, the station then complies with the medium-request signal. If the channel information identifies a channel other than the channel that the station is presently operating on, the station ignores the medium-request signal.

Abstract: A method and apparatus are disclosed for detecting a collision in a carrier sense multiple access wireless communication system. Each transmitting station includes a collision detector that evaluates one or more predefined criteria to determine when a collision has occurred. The collision detector evaluates the measured energy level and optionally payload and/or preamble detection information to determine if a collision has occurred. A collision occurred when an expected ACK message is not received, in the presence of an increased energy level and possibly preamble or payload detection information. The collision detector of the present invention can be activated, for example, at a time corresponding to the start of the 802.11 Short Inter Frame Space interval.

Abstract: In one embodiment, a Universal Serial Bus (USB) system assigns a first priority level to a first USB endpoint and a second priority level that is lower than the first priority level to a second USB endpoint. The USB system has memory that stores first USB data packets corresponding to the first priority level and second USB data packets corresponding to the second priority level. The USB system also has a controller that manages transfers of (i) the first USB data packets to the first USB endpoint and (ii) the second USB data packets to the second USB endpoint. If the memory concurrently stores first and second USB data packets, then the controller determines an order for transferring the first and second USB data packets based on the second priority level being lower than the first priority level and/or detection of a starvation condition for the second endpoint.

Abstract: A station for a communications network. In one embodiment, the station includes a decoder, a check processor, and a transmitter. The decoder is adapted to decode a received encoded data unit. The check processor is adapted to determine whether the encoded data unit has been correctly received. The transmitter is adapted to initiate, prior to the check processor completing the determination whether the encoded data unit has been correctly received, the transmission of an acknowledgment message comprising a frame having a plurality of different fields of data. The transmitter is adapted to modify the transmission of the acknowledgment message if the check processor determines that the data unit has not been correctly received.

Abstract: In one embodiment, a Universal Serial Bus (USB) system assigns a first priority level to a first USB endpoint and a second priority level that is lower than the first priority level to a second USB endpoint. The USB system has memory that stores first USB data packets corresponding to the first priority level and second USB data packets corresponding to the second priority level. The USB system also has a controller that manages transfers of (i) the first USB data packets to the first USB endpoint and (ii) the second USB data packets to the second USB endpoint. If the memory concurrently stores first and second USB data packets, then the controller determines an order for transferring the first and second USB data packets based on the second priority level being lower than the first priority level and/or detection of a starvation condition for the second endpoint.

Abstract: A station for a communications network. In one embodiment, the station includes a decoder, a check processor, and a transmitter. The decoder is adapted to decode a received encoded data unit. The check processor is adapted to determine whether the encoded data unit has been correctly received. The transmitter is adapted to initiate, prior to the check processor completing the determination whether the encoded data unit has been correctly received, the transmission of an acknowledgment message comprising a frame having a plurality of different fields of data. The transmitter is adapted to modify the transmission of the acknowledgment message if the check processor determines that the data unit has not been correctly received.

Abstract: A method for processing a received encoded data unit comprises: decoding the received encoded data unit; determining whether the encoded data unit has been correctly received; prior to completing the determination of whether the encoded data unit has been correctly received, initiating the transmission of an acknowledgment message; and modifying the transmission of the acknowledgment message if it is determined that the data unit has not been correctly received. In another embodiment, a station for a communications network comprises: a decoder adapted to decode a received encoded data unit; a check processor adapted to determine whether the encoded data unit has been correctly received; and a transmitter adapted to initiate the transmission of an acknowledgment message prior to the check processor completing the determination whether the encoded data unit has been correctly received.

Abstract: A medium-reservation mechanism improves transmission efficiency in a multiple-channel network that includes stations with limited-selectivity receivers. The mechanism employs a medium-request signal that conveys channel information. In this network, stations check the channel information in the medium-request signal to decide whether or not to comply with the medium-request signal. If the channel information identifies the channel that is close to the channel that the station is presently operating on, the station then complies with the medium-request signal. If the channel information identifies a channel other than the channel that the station is presently operating on, the station ignores the medium-request signal.

Abstract: In one embodiment, a network system has a plurality of access points, wherein each access point can be used for wireless communication with at least one station, wherein each access point can (1) receive a probe signal with either a first or second channel frequency and (2) generate and transmit, in response to the probe signal, a response signal with the first or second channel frequency. At least one access point selects at least one channel frequency for the wireless communication with the at least one station on the basis of at least one response signal received with the first channel frequency as transmitted by any of the other access points and/or at least one response signal received with the second channel frequency as transmitted by any of the other access points.

Abstract: A medium-reservation mechanism improves transmission efficiency in a multiple-channel network that includes stations with limited-selectivity receivers. The mechanism employs a medium-request signal that conveys channel information. In this network, stations check the channel information in the medium-request signal to decide whether or not to comply with the medium-request signal. If the channel information identifies the channel that is close to the channel that the station is presently operating on, the station then complies with the medium-request signal. If the channel information identifies a channel other than the channel that the station is presently operating on, the station ignores the medium-request signal.

Abstract: Medium access control device (301) for a mobile network station (3, 4, 5) or an access point (AP1) in a wireless local area network (1), having controlling means (302), processing means (303) and transmitting and receiving means (304); the controlling means (302) being arranged to control transmission and reception of radio frequency data signals containing data symbols; the transmitting and receiving means (304) being arranged for transmission and reception of electromagnetic data signals; the processing means (303) being arranged for detecting a first signal portion and a second signal portion in the received data signal, the second signal portion following the first signal portion and having a signal coding differing from a signal coding of the first signal portion.

Abstract: A method and system for servicing data traffic in wireless local area networks (such as IEEE 802.11 networks) in multiple queues having different levels of priority. These queues include at least a low priority queue for ‘best effort’ traffic, a medium priority queue for streaming data such as video pictures, and a high priority queue for voice traffic, and are serviced in order of decreasing priority. To prevent the ‘best effort’ traffic in the low priority queue from being ‘starved’, a bit is set to indicate when such a condition is likely to occur, and the low priority queue is served first when that bit has been set. Alternatively, low and medium priority traffic is handled on a weighted round-robin basis, and high priority traffic is given strict priority over both. Transmit and receive queues are handled on a rotating priority basis.

Abstract: A wireless local area network apparatus includes a transmitter and a receiver in which operation of the receiver is accurately synchronized with periodic signals from the transmitter. The periodic signals contain timing data indicating the state of a timer in the transmitter at the time the signal containing that data was transmitted and this timing data is retrieved from the signal when received by the receiver and loaded in a timer for controlling operation of the receiver.

Abstract: A wireless local area network apparatus includes a transmitter and a receiver in which operation of the receiver is accurately synchronized with periodic signals from the transmitter. The periodic signals contain timing data indicating the state of a timer in the transmitter at the time the signal containing that data was transmitted and this timing data is retrieved from the signal when received by the receiver and loaded in a timer for controlling operation of the receiver.

Abstract: Quality of Service (QoS) mechanisms and facilities are introduced into USB-based wireless Local Area Networking (LAN) communication systems. Techniques are provided for managing multiple priority queues in USB-based wireless communications systems, and for ensuring that lower priority traffic is not precluded from accessing the medium during sustained periods of use by high(er) priority traffic. A method is provided to resolve Quality of Service issues in emerging high-speed USB-based communications systems by offering support for multiple queue management within the system. A further embodiment provides an escalation mechanism for the purposes of mitigating low priority class data starvation in these communications systems, when it becomes an issue.

Abstract: A method for processing a received encoded data unit comprises: decoding the received encoded data unit; determining whether the encoded data unit has been correctly received; prior to completing the determination of whether the encoded data unit has been correctly received, initiating the transmission of an acknowledgment message; and modifying the transmission of the acknowledgment message if it is determined that the data unit has not been correctly received. In another embodiment, a station for a communications network comprises: a decoder adapted to decode a received encoded data unit; a check processor adapted to determine whether the encoded data unit has been correctly received; and a transmitter adapted to initiate the transmission of an acknowledgment message prior to the check processor completing the determination whether the encoded data unit has been correctly received.

Abstract: A medium-reservation mechanism improves transmission efficiency in a multiple-channel network that includes stations with limited-selectivity receivers. The mechanism employs a medium-request signal that conveys channel information. In this network, stations check the channel information in the medium-request signal to decide whether or not to comply with the medium-request signal. If the channel information identifies the channel that is close to the channel that the station is presently operating on, the station then complies with the medium-request signal. If the channel information identifies a channel other than the channel that the station is presently operating on, the station ignores the medium-request signal.

Abstract: A wireless local area network apparatus includes a transmitter and a receiver in which operation of the receiver is accurately synchronized with periodic signals from the transmitter. The periodic signals contain timing data indicating the state of a timer in the transmitter at the time the signal containing that data was transmitted and this timing data is retrieved from the signal when received by the receiver and loaded in a timer for controlling operation of the receiver.

Abstract: Method and device for communicating at least one packet of data with a predetermined packet size over a communication channel from a transmitter to a receiver, the transmitter having a memory for storing a common set of data rates, the method including the steps of fragmenting the at least one packet into a number of frames with a predetermined frame size by the transmitter, automatically selecting a combination of frame size and one of the common set of data rates by the transmitter such that the transmission time of each of the frames is limited to a predefined value, and transmitting each frame over the communication channel by the transmitter.

Abstract: A method and apparatus are disclosed for detecting a collision in a carrier sense multiple access wireless communication system. Each transmitting station includes a collision detector that evaluates one or more predefined criteria to determine when a collision has occurred. The collision detector evaluates the measured energy level and optionally payload and/or preamble detection information to determine if a collision has occurred. A collision occurred when an expected ACK message is not received, in the presence of an increased energy level and possibly preamble or payload detection information. The collision detector of the present invention can be activated, for example, at a time corresponding to the start of the 802.11 Short Inter Frame Space interval.