摘要:
A communication unit (10) can have at least a first receiver (11) and a second receiver (12). The latter typically consumes more power than the former during ordinary operation. Pursuant to one embodiment a communication unit can use the lower-power receiver to detect energy on a monitored channel while the second receiver is retained in a reduced power mode of operation. Upon detecting an absence of channel activity the second receiver can be restored to normal operability to effect such activities as are then presently required.
摘要:
The invention provides an enhanced passive scanning method for a wireless local area network, including the steps of receiving (405) at least one of a beacon signal (342, 348) or a gratuitous probe response (344), updating (435) a site timing table entry in a site timing table based on the received beacon signal (342, 348) or gratuitous probe response (344), setting (445) a scan start time based on entries in the updated site timing table, and determining (450) a power mode for a wireless communication device based on the scan start time. An enhanced passive scanning system (200, 500, 600) and computer usable medium for enhanced passive scanning is also disclosed.
摘要:
An access point utilizes information (11) as provided by various subscriber units to provide a message (12) (as included with, for example, a beacon transmission) that reflects near term likely utilization of a shared communication resource. A subscriber unit (20) can then utilize that information to schedule its own monitoring activity. This, in turn, permits the subscriber unit to similarly schedule power saving activities to accommodate this reception schedule.
摘要:
A system controller (106) is for transferring a low bit rate digital voice message. The system controller generates from an analog voice signal representing the voice message a set of speech model parameters, and generates a first derived set of speech model parameters from a first subset of the set of speech model parameters, the first derived set encoding the voice signal at a second voice quality and second vocoder rate that are less, respectively, than a first voice quality and vocoder rate. The system controller transmits (3610) the low bit rate-digital voice message comprising the first derived set of speech model parameters to a communication receiver (114). The communication receiver requests (3640) an incremental message when the quality of the voice message is unsatisfactory. The system controller generates and transmits (3555, 3650) an incremental message-and the communication receiver uses (3660) the incremental message to generate a higher quality voice message.
摘要:
A system controller (106) includes a speech encoder (107) that dynamically segments frames of a low bit rate digital voice message. Speech model parameters have been generated in a sequence of frames. The speech model parameters include quantized speech spectral parameter vectors. The speech encoder selects (1820) a first quantized speech spectral parameter vector as a current anchor vector, selects (1820, 1830) a second quantized speech spectral parameter vector located a predetermined number of frames (LMAX) from the current anchor vector as a target speech parameter vector, and perturbs (1840) the target speech parameter vector to derive a plurality (K) of perturbed speech parameter vectors.
摘要:
A method and apparatus is provided for a low bit rate speech transmission. Speech spectral parameter vectors are generated from a voice message and stored in a sequence of speech spectral parameter vectors within a speech spectral parameter matrix. A first index identifying a first speech parameter template corresponding to a first speech spectral parameter vector of the sequence of speech spectral parameter vectors is transmitted. A subsequent speech spectral parameter vector of the sequence is selected and a subsequent speech parameter template is determined having a subsequent index. One or more intervening interpolated speech parameter templates are interpolated between the first speech parameter template and the subsequent speech parameter template. The one or more intervening speech spectral parameter vectors are compared to the corresponding one or more intervening interpolated speech parameter templates to derive a distance. The subsequent index is transmitted when the distance derived is less than or equal to a predetermined distance.
摘要:
The invention concerns a method (200) and system for improving transmission or receipt of channel descriptors. The method can include the steps of—in a wireless communication system (100) that periodically broadcasts regular channel descriptors (310) at a set interval (312)—changing (212) a modulation scheme and transmitting (216) one or more supplementary channel descriptors (314) during the set interval between regular channel descriptors. The method can also include the step of periodically transmitting (214) a channel descriptor count (412) that provides an indication of the changed modulation scheme.
摘要:
A wireless local area network (WLAN) includes an access point (102) and a mobile station (106). The mobile station can operate in a low power mode by shutting down a WLAN subsystem (204) of the mobile station. While the mobile station is in a low power mode, the access point buffers data received at the access point destined for the mobile station (706). The mobile station wakes up to initiate a service period by transmitting a trigger frame to the access point, and identifies a traffic stream to be serviced in the presently initiated service period. The access point begins transmitting response frames to the mobile station, identifying the traffic stream requested by the mobile station, and in at least one response frame, the access point may indicate the buffer status of another traffic stream associated with the mobile station to allow the mobile station to make decisions regarding data retrieval and power save state.
摘要:
A mobile station (106) establishes a real time communication link via an access point (102) for carrying voice or other time-sensitive data. A WLAN subsystem (204) of the mobile station is normally kept in a low power state. Upon initiating a communication link the mobile station signals to the access point that unscheduled power save delivery mode will be used (614), and the access point reserves resources to assure the necessary quality of service. The mobile station initiates a frame transaction by first powering up the WLAN subsystem (712), acquiring the WLAN channel (407), and transmitting a polling frame. Upon successful receipt of the polling frame the access point prepares to reply with an aggregate response. The aggregate response commences by transmitting all data in an aggregate buffer, including both reserved and unreserved data buffers. Upon successful receipt of the aggregate response, the mobile station places the WLAN subsystem back into a low power state.
摘要:
A mobile station establishes a schedule by which data is exchanged with an access point. The schedule allows the mobile station to use a low power mode at times outside of the scheduled service periods. However, the mobile station may occasionally need to retrieve additional data from the access point, or transmit additional data to the access point, and so initiates an unscheduled service period to do so.