METHOD OF TRANSMITTING AND RECEIVING DATA IN WIRELESS COMMUNICATION SYSTEM AND APPARATUS THEREFOR (As Amended)

An user equipment (UE) for transmitting and receiving data in a wireless communication system, comprising:

• a communication unit for transmitting and receiving a radio signal with exterior;
• and
• a processor functionally connected to the communication unit,
• wherein the processor is configured to:
• receive, from a first base station (BS), a first message for informing that a radio link quality value of the first BS for a specific Mission Critical Service (MCS) is changed;
• receive, from at least one second BS, a second message including second radio link quality information associated with a radio link quality value of a second BS;
• and
• maintain the first BS or switching to one of the at least one second BS based on the received first radio link quality information and the second radio link quality information,
• wherein the first message includes first radio link quality information, and
• wherein the second radio link quality information includes at least one of a supportable radio link quality value for the MCS or a radio link quality value guaranteeing time indicating a time when the supportable radio link quality value is guaranteed.