Method for relaying messages in low power wide area network and apparatus therefor

An operation method of a relay in a communication system, the operation method comprising:

• performing a monitoring operation on a channel;
• performing a decoding operation on a message received in the channel when the message is IQ-inverted;
• and
• retransmitting the message when the decoded message is valid,
• wherein the retransmitted message is a message that is IQ-inverted.

A terminal in a communication system, the terminal comprising:

• a processor;
• a transmitter performing a transmission operation according to control of the processor;
• a receiver performing a reception operation according to control of the processor;
• and
• a memory storing at least one instruction executable by the processor,
• wherein the at least one instruction configures the processor to:
• transmit a first join request message to a base station without IQ inversion;
• when a number of failed transmissions of the first join request message is greater than or equal to a preconfigured threshold, transmit an IQ-inverted second join request message to a relay;
• and
• receive a join response message from the relay that is a response to the second join request message,
• wherein the second join request message is transmitted to the base station through the relay, and the join response message is generated by the base station.