Freescale Semiconductor,inc.

Motorola Corporation

Eric Perraud

Michel Burri

Marc Osajda

Christophe Comps

Bruno Baylac

A method of optimising the operation of a WLAN device which is used in the transmission and reception of a service over a medium includes determining a the value of a collision avoidance metric of the chip set at a specific time; predicting the available bandwidth of the WLAN from the value of the metric; determining the current data rate of the WLAN based on predicted available bandwidth and the type of service; and selecting a power amplifier bias voltage that is the minimum permitted for the determined current data rate to reduce the power consumption of the WLAN device.

Method and apparatus for enhanced data rate adaptation and lower power control in a WLAN semiconductor chip

A method of and apparatus for communication of conversational data signals, especially voice signals, between transceiver terminals over a radio link, especially a Bluetooth link, capable of full-duplex transmission of conversational data packets in alternate directions within a pair of time slots. Local conversational activity is detected at each of the terminals and conversational activity signals indicative of the detected local conversational activity are sent to the other terminal. Reception at either terminal is disabled if conversational activity signalling indicates absence of remote conversational activity, and transmission by either terminal is disabled in the absence of local conversational activity, saving power. Audible comfort noise may be generated at the terminal from a locally generated comfort noise signal if reception is disabled in response to the conversational activity signalling indicating absence of remote conversational activity.

Communicating conversational data between signals between terminals

A communication device comprising an internal power source, first and second receiver elements for receiving signals transmitted from the base station, and a processor selectively responsive to a modulation of the received signal to generate a data signal for transmission to the base station. The first receiver element has lower power consumption than the second receiver element does when energised. At least during a standby state of the device, the first receiver element is activated to detect the presence of a received signal, the second receiver element and the processing means being de-energised. The first receiver element is responsive to detection of a received signal to trigger an active state in which the second receiver element is activated to respond selectively to the frequency of the signal received to actuate the processor. The invention is applicable to vehicle access control systems, and tire pressure monitoring systems.

Passive communication device and passive access control system

A method of passive response communication, especially for an access control system, in which a first transponder () transmits an interrogation signal to a remote second transponder (), which responds by transmitting data back to the first transponder (), the two transponders each comprising a transmitter and a receiver, and a communication signal exchanged between said transponders () in at least one direction including a plurality of anti-relay-attack pulses (). At least one distinguishing pulse () selected among the anti-relay-attack pulses has a distinctive shape and the receiver of said communication signal is selectively responsive to the shapes of said plurality of pulses (). Interception of the transmitted signal in a relay attack using digital transceivers will not relay the distinctive shape and the response of the second transponder is inhibited.

Passive response communication system

A security system for actuating a security mechanism of a vehicle includes a transceiver coupled to the security mechanism and having one transmission channel for transmitting a first signal and a number of reception channels. A remote radio-frequency transponder key has a number of transmission channels and one reception channel matched to the respective reception and transmission channels of the transceiver. The transponder key is arranged to transmit an unlock signal to the transceiver upon reception of the first signal. The unlock signal is verified by the transceiver as valid before actuating the security mechanism. The transceiver is further arranged to select a channel for reception of the unlock signal and to embed the identity of the selected channel in the first signal, such that the transponder key transmits the unlock signal using the selected channel.

Security system and method

A sensor device (,) comprises a sensor package (,) having a cavity (,) formed therein, a sensor die (,) mounted on a bottom surface (,) of the cavity (,) and a protective coating (,) formed over the sensor die in the cavity. The protective coating (,) is formed from a material, preferably a polymer material, which is arranged to have a graduated cross-linking density such that the material at the top of the cavity (,) has a high density of cross-linking and the material at the bottom of the cavity (,), which material is in contact with the sensor die, has a low density of cross-linking.

Growing community of inventors

Tournefeuille, France

Eric Perraud