Communication system, communication apparatus and communication method
First Claim
1. A communication device for receiving and sending data by modulating and demodulating an electromagnetic wave, comprising:
- circuitry configured togenerate the electromagnetic wave to generate a radio frequency (RF) field,modulate the electromagnetic wave to send data at any of a plurality of transfer rates,detect an electromagnetic wave from another communication device, anddemodulate the electromagnetic wave from the other communication device to obtain data sent by the other communication device at any of a plurality of transfer rates,wherein, in an active mode, the circuitry is configured to start to send the data after generation of the electromagnetic wave starts and when the electromagnetic wave from the other communication device is not detected at a level of a first threshold or more.
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Abstract
A method for a communication device includes determining whether a first radio frequency (RF) signal at a level of at least a first predetermined field threshold is detected. The method also includes generating a second RF signal at a level of at least a second predetermined field threshold greater than the first predetermined field threshold, when the communication device receives an instruction to generate the second RF signal and the determining determines that the first RF signal at the level of at least the first predetermined field threshold is not detected. The method further includes receiving a load modulated RF signal in response to the second RF signal.
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Citations
8 Claims
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1. A communication device for receiving and sending data by modulating and demodulating an electromagnetic wave, comprising:
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circuitry configured to generate the electromagnetic wave to generate a radio frequency (RF) field, modulate the electromagnetic wave to send data at any of a plurality of transfer rates, detect an electromagnetic wave from another communication device, and demodulate the electromagnetic wave from the other communication device to obtain data sent by the other communication device at any of a plurality of transfer rates, wherein, in an active mode, the circuitry is configured to start to send the data after generation of the electromagnetic wave starts and when the electromagnetic wave from the other communication device is not detected at a level of a first threshold or more. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method to cause a communication device to receive and send data by modulating and demodulating an electromagnetic wave, comprising:
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generating, with circuitry, the electromagnetic wave to generate a radio frequency (RF) field; modulating, with the circuitry, the electromagnetic wave to send data at any of a plurality of transfer rates; detecting, with the circuitry, an electromagnetic wave from another communication device; and demodulating, with the circuitry, the electromagnetic wave from the other communication device to obtain data sent by the other communication device at any of a plurality of transfer rates, wherein, in an active mode, sending the data is started after generation of the electromagnetic wave starts and when the electromagnetic wave from the other communication device is not detected at a level of a first threshold or more.
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Specification