Method and apparatus for performing communication in wireless power transmission system

A method of data transmission performed by a wireless power transmitter, the method comprising:

• transferring wireless power to a wireless power receiver by using magnetic coupling between the wireless power transmitter and the wireless power receiver;
• setting a target power level based on a charging condition;
• receiving, from the wireless power receiver, a received power packet (RPP) which indicates a value of the wireless power received by the wireless power receiver;
• transmitting a bit pattern to the wireless power receiver in response to the RPP, the bit pattern being used to request communication initiated by the wireless power transmitter;
• receiving, from the wireless power receiver, a response packet to allow the communication initiated by the wireless power transmitter;
• transmitting, to the wireless power receiver, information indicating the target power level in response to the response packet;
• and
• negotiating a guaranteed power level adjusted by the wireless power receiver such that the target power level is kept equal to or larger than the guaranteed power level.

A wireless power receiver comprising:

• a power pickup unit configured to receive wireless power from a wireless power transmitter by using magnetic coupling between the wireless power transmitter and the wireless power receiver;
• and
• a communication/control unit configured to control the wireless power and to perform transmission or reception of data based on communication with the wireless power transmitter,
• wherein the communication/control unit further configured to:
• transmit, to the wireless power transmitter, a received power packet (RPP) which indicates a value of the wireless power received by the wireless power receiver,
• receive a bit pattern from the wireless power transmitter in response to the RPP, the bit pattern being used for the wireless power transmitter to request communication initiated by the wireless power transmitter,
• transmit, to the wireless power transmitter, a response packet to allow the communication initiated by the wireless power transmitter,
• receive, from the wireless power transmitter, information indicating the target power level in response to the response packet,
• adjust a guaranteed power level adjusted by the wireless power receiver such that the target power level is kept equal to or larger than the guaranteed power level,
• negotiate the guaranteed power level with the wireless power transmitter.

A method of data reception performed by a wireless power receiver, the method comprising:

• receiving wireless power from a wireless power transmitter by using magnetic coupling between the wireless power transmitter and the wireless power receiver;
• transmitting, to the wireless power transmitter, a received power packet (RPP) which indicates a value of the wireless power received by the wireless power receiver;
• receiving a bit pattern from the wireless power transmitter in response to the RPP, the bit pattern being used for the wireless power transmitter to request communication initiated by the wireless power transmitter;
• transmitting, to the wireless power transmitter, a response packet to allow the communication initiated by the wireless power transmitter;
• receiving, from the wireless power transmitter, information indicating the target power level in response to the response packet;
• adjusting a guaranteed power level adjusted by the wireless power receiver such that the target power level is kept equal to or larger than the guaranteed power level;
• and
• negotiating the guaranteed power level with the wireless power transmitter.