Method and apparatus for indicating two-step random access procedure in wireless communication system

Abstract

The disclosure relates to a communication technique for convergence of a fifth-generation (5G) or pre-5G communication system for supporting a higher data transmission rate beyond a fourth-generation (4G) communication system, such as Long-Term Evolution (LTE), with an IoT technology, and a system therefor. The disclosure may be applied to an intelligent service (for example, smart home, smart building, smart city, smart car or connected car, health care, digital education, retail business, security and safety-related service, etc.) on the basis of a 5G communication technology and an IoT-related technology. A method and an apparatus is provided for applying two-step random access when 3rd generation partnership project (3GPP) 5G new radio (NR) technology is used in an unlicensed band.

What is claimed is: 
     
         1 . A method performed by a user equipment (UE) in a wireless communication system, the method comprising:
 receiving, from a first base station, a handover indication message including preamble indication information on the UE and random access (RA) resource information; and   transmitting, to a second base station, a message A (Msg A) for a handover, based on the preamble indication information on the UE and the RA resource information included in the handover indication message.   
     
     
         2 . The method of  claim 1 , wherein the transmitting of the message A comprises:
 transmitting a random access preamble corresponding to the preamble indication information at a first time; and   transmitting an uplink signal, based on the RA resource information, at a second time.   
     
     
         3 . The method of  claim 2 , wherein the uplink signal includes an RRCReconfigurationComplete message. 
     
     
         4 . The method of  claim 1 , wherein the handover indication message includes reconfigurationWithSync. 
     
     
         5 . The method of  claim 2 , wherein a gap with a random length is present between the first time and the second time. 
     
     
         6 . A method performed by a first base station in a wireless communication system, the method comprising:
 generating a handover indication message including preamble indication information and random access (RA) resource information for a handover of a user equipment (UE); and   transmitting the generated handover indication message to the UE, the preamble indication information on the UE and the RA resource information included in the handover indication message being for transmitting a message A (Msg A) for the handover of the UE to a second base station.   
     
     
         7 . The method of  claim 6 , wherein message A transmits a random access preamble corresponding to the preamble indication information at a first time and transmits an uplink signal, based on the RA resource information, at a second time. 
     
     
         8 . The method of  claim 7 , wherein the uplink signal includes an RRCReconfigurationComplete message. 
     
     
         9 . The method of  claim 6 , wherein the handover indication message includes reconfigurationWithSync. 
     
     
         10 . The method of  claim 7 , wherein a gap with a random length is present between the first time and the second time. 
     
     
         11 . A user equipment (UE) in a wireless communication system, the UE comprising:
 a transceiver; and   a processor configured to:
 receive, from a first base station via the transceiver, a handover indication message comprising preamble indication information on the UE and random access (RA) resource information, and 
 transmit, to a second base station via the transceiver, a message A (Msg A) for a handover, based on the preamble indication information on the UE and the RA resource information included in the handover indication message. 
   
     
     
         12 . The UE of  claim 11 , wherein the processor is further configured to:
 transmit the message A including a random access preamble corresponding to the preamble indication information at a first time, and   transmit an uplink signal, based on the RA resource information, at a second time.   
     
     
         13 . The UE of  claim 12 , wherein the uplink signal includes an RRCReconfigurationComplete message. 
     
     
         14 . The UE of  claim 11 , wherein the handover indication message includes reconfigurationWithSync. 
     
     
         15 . The UE of  claim 12 , wherein a gap with a random length is present between the first time and the second time. 
     
     
         16 . A first base station in a wireless communication system, the first base station comprising:
 a transceiver; and   a processor configured to:
 generate a handover indication message comprising preamble indication information and RA resource information for a handover, 
 transmit, to a user equipment (UE) via the transceiver, the generated handover indication message, and 
   wherein the preamble indication information on the UE and the RA resource information included in the handover indication message is for transmitting a message A (Msg A) for the handover of the UE to a second base station.   
     
     
         17 . The first base station of  claim 16 , wherein message A transmits a random access preamble corresponding to the preamble indication information at a first time and transmits an uplink signal, based on the RA resource information, at a second time. 
     
     
         18 . The first base station of  claim 17 , wherein the uplink signal includes an RRCReconfigurationComplete message. 
     
     
         19 . The first base station of  claim 16 , wherein the handover indication message includes reconfigurationWithSync. 
     
     
         20 . The first base station of  claim 17 , wherein a gap with a random length is present between the first time and the second time.