Abstract: A context controller for managing multitasking in a processor and a method of operating the same. In one embodiment, the context controller includes: (1) an event recorder that records occurrences of predetermined events and (2) an event acknowledger, associated with the event recorder, that acknowledges ones of the events based on an identity of a currently-active context.

Abstract: The present invention provides a system and method, operable in a multi-context processor, for allowing a current context to change an event sensitivity of a future context. In one embodiment, the system includes a context control register, accessible to the current context, for receiving event mask data defining the event sensitivity of the future context. The system further includes a context controller, associated with the context control register and invokable from within the current context, that causes the event mask data to be employed in defining a content of an event mask register of the future context.

Abstract: In one embodiment, a method of transmitting data from a transmitter in a wireless local area network (WLAN), where the transmitter has a timer and a modem. The transmitter periodically transmits a transmission signal that includes a timestamp field that includes a timestamp for synchronizing a receiver timer in a receiver of the WLAN. The timestamp, which represents a value within the count sequence of the transmitter timer, accounts for delays in the modem.

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: A context controller for managing multitasking in a processor and a method of operating the same. In one embodiment, the context controller includes: (1) a time slice instruction counter that counts a number of instructions executed with respect to a given background task and (2) a background task controller that cyclicly executes a context corresponding to another background task when the number of instructions executed equals a dynamically-programmable time slice value.

Abstract: The present invention provides a system and method, operable in a multi-context processor, for allowing a current context to change an event sensitivity of a future context. In one embodiment, the system includes a context control register, accessible to the current context, for receiving event mask data defining the event sensitivity of the future context. The system further includes a context controller, associated with the context control register and invokable from within the current context, that causes the event mask data to be employed in defining a content of an event mask register of the future context.

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: 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 system includes a plurality of base stations connected in a wired local area network. A mobile wireless station can roam through communication cells defined by the base stations. The base stations transmit beacon messages at regular intervals. The mobile station determines the communications quality of the beacon message for the cell in which the mobile station is currently located and if this quality becomes unacceptable, switches to a search mode wherein beacon messages from any base station are received and their communications quality is determined. The mobile station switches to communicate with a base station providing a beacon message with an acceptable communications quality.

Abstract: A context controller for managing multitasking in a processor and a method of operating the same. In one embodiment, the context controller includes: (1) foreground and background task controllers that allocate processor resources to active contexts corresponding to foreground and background tasks, respectively, and (2) mode switching circuitry, coupled to the foreground and background task controllers, that places the processor in an idle state and a power saving mode when all of the contexts are inactive.

Abstract: A context controller for managing multitasking in a processor and a method of operating the same. In one embodiment, the context controller includes: (1) memory that contains contexts corresponding to background tasks to be executed in the processor, the contexts having status indicators associated therewith and (2) a background task controller that reads the status indicators associated with the contexts and cyclicly activates the contexts based on the status indicators.

Abstract: A context controller for managing multitasking in a processor and a method of operating the same. In one embodiment, the context controller includes: (1) an event recorder that records occurrences of events and (2) an encoder, associated with the event recorder, that, in response to a software instruction, priority encodes bits corresponding to at least some of the events to generate therefrom an event-dependent vector to allow the processor to branch as a function thereof. Vectoring is per-instance of the vector decode software instruction, not per-event or per-context.

Abstract: A wireless data communication system is operable in a power saving mode wherein stations are synchronized to be in an awake state to receive synchronizing messages (TIM, PSYNC) and traffic indicator information and are changed to a doze state if they are not to receive data messages. In one embodiment all stations (20) communicate via a base station access point (16), which broadcasts synchronizing messages (TIM) at regular intervals identifying stations (20) that are to receive data messages. In another embodiment all stations (220) communicate directly with one another, one station assumes the role of a master station and broadcasts synchronizing messages (PSYNC), and stations (220) desiring to transmit data messages transmit traffic indicator messages (PTIM) to the appropriate destination stations (220), in a synchronized awake period just before the next synchronizing message (PSYNC) is expected to arrive.

Abstract: For use with a wireless computer network having a plurality of access points, a mobile station adapted for communicating with the network via a current access point and having a scanning circuit for locating a new access point, the scanning circuit requiring a scanning period of time to locate the new access point, a method of operation of the mobile station and a wireless computer network infrastructure. The mobile station comprises: (1) a detection circuit that generates a ready-to-scan signal indicating that the mobile station is about to activate the scanning circuit and (2) a suspension circuit, coupled to the detection circuit, that receives the ready-to-scan signal and generates, in response thereto, a data suspend signal for transmission to the current access point, the data suspend signal causing the current access point to suspend transmission of data to the mobile station, thereby preventing loss of the data during the scanning period.

Abstract: A wireless local area network (10) including a plurality of stations (12) utilizes dynamic transmit power level control such that only the power level needed for reliable transmission to a particular station (12) is utilized. Each transmitted information packet (80) contains a byte (92) representing the power level at which the packet (80) was transmitted. The power level at which the packet (80) is received is measured and a path attenuation value is calculated, averaged over a plurality of packets and utilized, together with a measured interference level also transmitted in the packet (80), to determined a transmit power level for that path. Also determined is an associated defer threshold level. The transmit power levels and associated defer threshold levels are stored in a table (270).

Abstract: A wireless communication system includes a plurality of stations each having a plurality of antennas. A first packet, containing a training signal portion is transmitted from a transmitting station using a first selected antenna and received at a receiving station using a second selected antenna which is selected as the antenna giving the best received signal quality, determined during the training signal period. Following transmission of the first packet, a control signal (ACKCNTL) is generated in both the transmitting station and the receiving station to condition these stations for the transmission from the receiving station of a response packet via the same antenna pair used for the information packet transmission. Thus, the response packet need have only a relatively short training signal portion.

Abstract: A station which broadcasts a frame of information over a wireless local area network, waits a predetermined time calculated to allow other stations to gain access to the network, and thereafter broadcasts another frame of information. A method is provided which improves access fairness while reducing the collision probability, thereby increasing data throughput in the network.

Abstract: A wireless data communication system is operable in a power saving mode wherein stations are synchronized to be in an awake state to receive synchronizing messages (TIM, PSYNC) and traffic indicator information and are changed to a doze state if they are not to receive data messages. In one embodiment all stations (20) communicate via a base station access point (16), which broadcasts synchronizing messages (TIM) at regular intervals identifying stations (20) that are to receive data messages. In another embodiment all stations (220) communicate directly with one another, one station assumes the role of a master station and broadcasts synchronizing messages (PSYNC), and stations (220) desiring to transmit data messages transmit traffic indicator messages (PTIM) to the appropriate destination stations (220), in a synchronized awake period just before the next synchronizing message (PSYNC) is expected to arrive.