Negotiating communication parameters between near field communications (NFC) capable devices
An apparatus and method is disclosed to negotiate communications parameters between near field communications (NFC) capable devices. In some embodiments, the NFC capable devices operate in a negotiation phase to negotiate one or more communications parameters prior to transferring information. In other embodiments, the NFC capable devices simultaneously negotiate the one or more communications parameters with the transferring of the information.
1. A method for negotiating a communication parameter between near field communications (NFC) capable communication devices, comprising:
maintaining, by a first NFC capable communication device, an unmodulated data communication at a first power for a first duration in accordance with the communication parameter;
receiving, by the first NFC capable communication device, a request communication from a second NFC capable communication device during the first duration indicating that the first communication parameter is insufficient;
adjusting, by the first NFC capable communication device, the communication parameter in accordance with the request communication during the first duration to provide a second communication parameter; and
providing, by the first NFC capable communication device, a second unmodulated data communication at a second power during a second duration in accordance with the second communication parameter, the second power being different from the first power.
2. The method of claim 1 , further comprising:
modulating, by the first NFC capable communication device, a first data communication onto a carrier wave to provide a modulated data communication to the second NFC capable communication device, the first data communication including the communication parameter and information that is to be transferred to the second NFC capable communication device.
3. The method of claim 2 , wherein the modulating comprises:
encapsulating the communication parameter into a header portion of a data frame and the information into a data portion of the data frame;
modulating the data frame with the carrier wave to provide a modulated data frame; and
generating a magnetic field using the modulated data frame in accordance with the communication parameter to provide the modulated data communication.
4. The method of claim 2 , further comprising:
receiving, by the first NFC capable communication device, a response to the modulated data communication from the second NFC capable communication device.
5. The method of claim 1 , wherein the communication parameter relates to a power of the unmodulated data communication.
6. The method of claim 4 , wherein the communication parameter comprises:
a transmission power level;
an antenna configuration; or
a modulation scheme.
7. The method of claim 1 , wherein the communication parameter comprises:
a first parameter, which when used by the first NFC capable communication device, affects a duration of the unmodulated data communication;
a second parameter, which when used by the first NFC capable communication device, affects a duration of a modulated data communication;
a third parameter, which when used by the first NFC capable communication device, affects a power of the unmodulated data communication; or
a fourth parameter, which when used by the first NFC capable communication device, affects a power of the modulated data communication.
8. The method of claim 1 , wherein the providing comprises:
maintaining the second unmodulated data communication at the second power during the second duration in accordance with the second communication parameter.
9. The method of claim 1 , wherein the second NFC capable communication device cannot recover, process, or provide a response to information when the unmodulated data communication is at the first power during the first duration.
10. A near field communications (NFC) capable apparatus for negotiating a communication parameter between NFC capable communication devices, comprising:
a modulator module; and
a controller module configured to:
cause the modulator module to maintain an unmodulated data communication at a first power during a first duration in accordance with the communication parameter;
receive a request from a NFC capable communication device during the first duration indicating that the first communication parameter is insufficient,
adjust the communication parameter in accordance with the request during the first duration to provide a second communication parameter, and
cause the modulator module to provide a second unmodulated data communication at a second power during a second duration in accordance with the second communication parameter, the second power being different from the first power.
11. The NFC capable apparatus of claim 10 , wherein the modulator module is configured to modulate a first data communication onto a carrier wave to provide a modulated data communication to the NFC capable communication device, the first data communication including the communication parameter and information that is to be transferred to the NFC capable communication device.
12. The NFC capable apparatus of claim 11 , wherein the modulator module is further configured to:
encapsulate the communication parameter into a header portion of a data frame and the information into a data portion of the data frame, and
modulate the data frame with the carrier wave to provide a modulated data frame, wherein the modulator module further comprises:
an antenna module configured to generate a magnetic field using the modulated data frame in accordance with the communication parameter to provide the modulated data communication.
13. The NFC capable apparatus of claim 11 , wherein the controller module is further configured to receive a response to the modulated data communication from the NFC capable communication device.
14. The NFC capable apparatus of claim 10 , wherein the communication parameter relates to a power of the unmodulated data communication.
15. The NFC capable apparatus of claim 10 , further comprising:
a demodulator configured to demodulate a request communication from the NFC capable communication device to provide the request.
16. The NFC capable apparatus of claim 10 , wherein the communication parameter comprises:
a first parameter, which when used by the NFC capable apparatus, affects a duration of the unmodulated data communication;
a second parameter, which when used by the NFC capable apparatus, affects a duration of a modulated data communication;
a third parameter, which when used by the NFC capable apparatus, affects a power of the unmodulated data communication; or
a fourth parameter, which when used by the NFC capable apparatus, affects a power of the modulated data communication.
17. The NFC capable apparatus of claim 10 , wherein the modulator module is configured to maintain the second unmodulated data communication at the second power during the second duration in accordance with the second communication parameter.
18. The NFC capable apparatus of claim 10 , wherein the NFC capable communication device cannot recover, process, or provide a response to information when the unmodulated data communication is at the first power during the first duration.