Method and device for searching for alternative link in wireless communication system

A method of supporting a user equipment to search for an alternative link by a serving link base station in a wireless communication system, the method comprising:

• receiving a radio resource control (RRC) connection request message from the user equipment;
• transmitting, to the user equipment, service information containing a target quality value of a service to be provided to the user equipment if the RRC connection request message indicates that the user equipment supports predetermined services;
• determining a scheduling reference quality value to be used for scheduling the user equipment at a future time according to a result of estimating a buffer status at the future time;
• and
• transmitting an indicator indicating the determined scheduling reference quality value and the future time to the user equipment,
• wherein the search of the alternative link of the user equipment is triggered based on the target quality value and the scheduling reference quality value.

A user equipment searching for an alternative link in a wireless communication system, comprising:

• a receiver configured to receive service information including a target quality value of a service to be provided to the user equipment from a serving link base station;
• and
• a processor, operatively coupled to the receiver, configured to determine whether to search for a first alternative link based on a scheduling reference quality value to be used for scheduling the user equipment by the serving link base station at a future time and the target quality value, to search for candidate base stations to configure the first alternative link upon determining to search for the first alternative link, and to establish the first alternative link with a first candidate base station among the searched candidate base stations in a mode in which unicast data transmission/reception is deactivated,
• wherein the processor is further configured to:
• compare a log value of the target quality value with a log sum of a quality value obtained from the candidate base stations and the scheduling reference quality value, and
• report to the serving link base station, a result of the comparison and a list of candidate base stations of which the log sum is equal to or less than the log value of the target quality value,
• wherein the first candidate base station is selected from the list of the candidate base stations.