Method and apparatus for transmitting and receiving data using bluetooth technology

A client device transmitting and receiving data to and from a server by using Bluetooth, the device comprising:

• a communication unit for communicating with an external entity in a wireless and wired manner;
• a memory for storing data;
• and
• a processor functionally connected to the communication unit, wherein the processor is configured to:
• establish a Bluetooth Low Energy (LE) connection to a server;
• transmit, to the server, a first readout request message requesting reading of a first characteristic including first association status information, wherein
• the first association status information is part of specific association status information representing association status between the server and at least one device;
• receive, from the server, a first readout response message including the first association status information;
• and
• when the association status is changed, receive, from the server, an indication message including changed association status information included in a second characteristic, wherein
• the changed association status information represents changed association status between the server and the at least one device.