CONNECTION METHOD AND APPARATUS FOR OUT-OF-BAND COMMUNICATION IN WIRELESS POWER TRANSMISSION SYSTEM

The present disclosure provides a wireless power transmission method performed by a wireless power transmitter in a wireless power transmission system, and an apparatus using same, the method comprising: in a setup phase, receiving a setup packet from a wireless power receiver, wherein the setup packet related to the wireless power receiver includes information about whether a function for out-of-band communication is supported; in a negotiation phase, transmitting a capability packet to the wireless power receiver, wherein the capability packet related to the wireless power transmitter includes information about whether a function for the out-of-band communication is supported; and in the negotiation phase, receiving a first specific request (SRQ) packet related to an end of the negotiation phase from the wireless power receiver, and transmitting ACK for the first SRQ packet to the wireless power receiver, wherein the wireless power transmitter starts a connection to the out-of-band communication on the basis of transmission of the ACK for the first SRQ packet.