Working Mode Negotiating Method, Device, and System

A working mode negotiating method, wherein the method comprises:

• sending, by a second device, a negotiation message to a first device after detecting the first device, wherein the negotiation message is used to trigger the first device to activate a peer to peer (P2P) mode when the first device determines that information about a commodity for which a prepayment has been made successfully needs to be acquired from the second device, or to activate a card emulation mode when the first device determines that information about a commodity for which a prepayment has been made successfully does not need to be acquired from the second device;
• receiving, by the second device, an activated working mode sent by the first device, and activating a working mode that is the same as the activated working mode, wherein the activated working mode comprises the P2P mode or the card emulation mode;
• and
• performing communication according to the activated working mode when the second device and the first device perform communication using near field communication (NFC) technology.

A first device for working mode negotiation, wherein the first device comprises:

• a first receiver configured to receive a negotiation message that a second device sends after detecting the first device;
• a first processor configured to activate a peer to peer (P2P) mode when it is determined that information about a commodity for which a prepayment has been made successfully needs to be acquired from the second device, or to activate a card emulation mode when it is determined that information about a commodity for which a prepayment has been made successfully does not need to be acquired from the second device;
• a first transmitter configured to send an activated working mode to the second device, so that the second device activates a working mode that is the same as the activated working mode, wherein the activated working mode comprises the P2P mode or the card emulation mode;
• and
• a first near field communication (NFC) transceiver configured to perform communication according to the activated working mode when the first device and the second device perform communication using NFC technology.