Method of transmitting and receiving radio access information in a wireless mobile communications system

Abstract

In a wireless mobile communications system, a method of transmitting and receiving radio access information that allows a faster and an efficient way of establishing a radio connection between a terminal and a target base station while performing a handover for the terminal to a cell of the target base station. The network transmits in advance, the radio access information and the like, to the terminal so that the terminal can be connected with the target cell in a faster manner which minimizes the total time for the handover process.

What is claimed is: 
     
       1. A method of performing a random access procedure in a mobile communications system, the method comprising:
 receiving, by a terminal, a handover command message from a source base station,   wherein the handover command message includes preamble information for the random access procedure,   wherein the preamble information is a specific preamble used only for a specific terminal, and   wherein the specific preamble is determined by a target base station; and   performing, by the terminal, the random access procedure with the target base station using the specific preamble.   
     
     
       2. The method of  claim 1 , wherein the handover command message is generated by the target base station. 
     
     
       3. The method of  claim 1 , wherein the handover command message is transferred by the source base station to the specific terminal. 
     
     
       4. The method of  claim 1 , further comprising: transmitting, by the terminal, a measurement report to the source base station by measuring a condition of a downlink physical channel for other cells periodically or upon an occurrence of an event. 
     
     
       5. The method of  claim 4 , wherein the measurement report is used to determine whether to perform a handover from a current cell to the other cell. 
     
     
       6. The method of  claim 1 , wherein the preamble information includes frequency information and time information. 
     
     
       7. A method of performing a random access procedure in a mobile communications system, the method comprising:
 receiving, by a source base station, a handover command message from a target base station,   wherein the handover command message includes preamble information for the random access procedure,   wherein the preamble information is a specific preamble used only for a specific terminal, and   wherein the specific preamble is determined by a target base station; and   transferring, by the source base station, the received handover command message to the specific terminal, wherein the specific preamble is used to perform the random access procedure.   
     
     
       8. The method of  claim 7 , wherein the handover command message is generated by the target base station. 
     
     
       9. The method of  claim 7 , wherein the preamble information includes frequency information and time information. 
     
     
       10. A method of performing a random access procedure in a mobile communications system, the method comprising:
 generating, by a target base station, a handover command message,   wherein the handover command message includes preamble information for the random access procedure,   wherein the preamble information is a specific preamble used only for a specific terminal; and   transmitting, by the target base station, the handover command message to a source base station,   wherein the handover command message is transferred by a source base station to the specific terminal, wherein the specific preamble is used to perform the random access procedure.   
     
     
       11. The method of  claim 10 , wherein the preamble information includes frequency information and time information. 
     
     
       12. A mobile terminal that performs a random access procedure in a mobile communications system, the mobile terminal comprising:
 a radio protocol adapted to receive the handover command message from a source base station, and to perform the random access procedure with a target base station, wherein the handover command message includes preamble information for the random access procedure, wherein the preamble information is a specific preamble used only for a specific terminal, wherein the specific preamble is determined by a target base station, wherein the specific preamble is used to perform the random access procedure.   
     
     
       13. The terminal of  claim 12 , wherein the source base station and the target base station are a source enhanced Node B (source eNB) and a target enhanced Node B (target eNB) respectively in an Evolved Universal Mobile Telecommunication System (E-UMTS). 
     
     
       14. A method to perform a random access procedure in a mobile communications system comprising:
 receiving, by a terminal, a handover command message from a source base station which has determined that a handover should occur to a target base station, wherein the handover command message includes information related to a preamble for the terminal previously defined in a handover confirm message sent from the target base station to the source base station;   in response to the handover command message, performing, by the terminal, a random access procedure with the target base station to connect with the target base station using the information related to the preamble; and   transmitting, by the terminal, a handover complete message to the target base station.   
     
     
       15. The method of claim 14, wherein the handover command message includes time and frequency information to connect the target base station and the terminal. 
     
     
       16. The method of claim 14, further comprising receiving, in the terminal, time and frequency information from the source base station for use in connecting to the target base station. 
     
     
       17. The method of claim 14, wherein performing the random access procedure with the target base station using the information related to the preamble comprises transmitting, by the terminal to the target base station, a preamble sequence in accordance with the information related to the preamble. 
     
     
       18. A mobile terminal to transmit uplink data in a wireless communication system, the mobile terminal comprising:
 a transceiver configured to transmit the uplink data;   a memory configured to store the uplink data; and   a processor cooperating with the transceiver and the memory, the processor configured to:
 receive a handover command message from a source base station which has determined that a handover should occur to a target base station; 
 wherein the handover command message includes information related to a preamble for the terminal previously defined in a handover confirm message sent from the target base station to the source base station; 
 in response to the handover command message, perform, by the terminal, a random access procedure with the target base station to connect with the target base station using the information related to the preamble; and 
 transmit a handover complete message to the target base station. 
   
     
     
       19. The mobile terminal of claim 18, wherein the handover command message includes time and frequency information to connect the target base station and the terminal. 
     
     
       20. The mobile terminal of claim 18, wherein the processor is further configured to receive, in the terminal, time and frequency information from the source base station for use in connecting to the target base station. 
     
     
       21. The mobile terminal of claim 18, wherein the processor is further configured to perform the random access procedure with the target base station using the information related to the preamble comprises transmitting, by the terminal to the target base station, a preamble sequence in accordance with the information related to the preamble.