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 of performing a handover from a terminal to a base station in a wireless communication system, the method comprising:
 transmitting, by the terminal, measurement information to a source base station;   receiving, by the terminal, and after the source base station has determined that a handover should occur to a target base station, a handover command message from the source base station, wherein the handover command message includes access information, and the access information includes preamble information as identified by the target base station for use by the terminal during a random access procedure with the target base station, wherein the preamble information is a dedicated preamble used only for a specific terminal;   establishing, by the terminal, and in response to the handover command message, a radio connection with the target base station, wherein the terminal connects with the target base station during the random access procedure using the preamble information identified by the target base station; and   transmitting, by the terminal, a handover complete message to the target base station.   
     
     
       15. The method of claim 14, wherein the measurement information is a measurement report including channel conditions. 
     
     
       16. The method of claim 14, wherein the target base station is a base station located in a cell with improved channel conditions. 
     
     
       17. The method of claim 14, wherein the handover command message includes a handover command with a terminal identification, and wherein the target base station determines the terminal identification using the preamble information. 
     
     
       18. The method of claim 14, wherein the handover command message includes time and frequency information for use in connecting the target base station and the terminal. 
     
     
       19. The method of claim 14, wherein the preamble information is a dedicated preamble used only for the terminal during a random access channel transmission by the terminal. 
     
     
       20. The method of claim 14, wherein the handover command message further includes system information used for connecting the target base station to the terminal before the terminal establishes the radio connection with the target base station using a random access channel. 
     
     
       21. The method of claim 20, wherein the terminal establishes the radio connection without reading the system information of the target base station. 
     
     
       22. The method of claim 20, wherein the radio connection between the target base station and the terminal further includes the target base station receiving the dedicated preamble and identifying the terminal based in part on the dedicated preamble. 
     
     
       23. A wireless terminal device adapted to communicate data to and receive data from a source base station and a target base station in a network with a plurality of terminals including the wireless terminal device, comprising:
 a memory;   a transceiver; and   a processor in communication with the transceiver and the memory, the processor configured to:   transmit measurement information to the source base station;   receive a handover command message from the source base station as a result of the source base station having determined that a handover should occur to the target base station, wherein the handover command message includes access information, and the access information includes preamble information having been identified by the target base station for use by the wireless terminal device during a random access channel transmission with the target base station, wherein the preamble information is a dedicated preamble used only for a specific terminal;   establish, in response to the handover command message, a radio connection with the target base station, wherein the wireless terminal device connects with the target base station during the random access channel transmission using the signature and preamble information identified by the target base station; and   transmitting, by the wireless terminal device, a handover complete message to the target base station.   
     
     
       24. The wireless terminal device of claim 23, wherein the handover command message includes a handover command with a terminal identification. 
     
     
       25. The wireless terminal device of claim 24, wherein the dedicated preamble is used only for the wireless terminal device during the random access channel transmission by the wireless terminal device. 
     
     
       26. The wireless terminal device of claim 23, wherein the handover command message further includes system information used for connecting the target base station to the wireless terminal device before the wireless terminal device establishes the radio connection with the target base station using a random access channel. 
     
     
       27. A method of receiving a channel transfer in a wireless communication system, the method comprising:
 receiving, by a target base station, and after a source base station has determined that a handover should occur to the target base station, a handover request message from the source base station;   transmitting, by the target base station, a handover confirm message to the source base station; and   receiving, by the target base station, and in response to a handover command message, a radio connection to a terminal, wherein the radio connection includes access information, and the access information includes preamble information as identified by the target base station for use by the terminal during a random access channel transmission, and wherein the terminal connects with the target base station during the random access channel transmission using the access information and preamble information identified by the target base station.   
     
     
       28. The method of claim 27, wherein the handover request message includes a handover request with a terminal identification. 
     
     
       29. The method of claim 28, wherein the target base station determines the terminal identification using the preamble information. 
     
     
       30. The method of claim 29, wherein the dedicated preamble is used only for the terminal during the random access channel transmission by the terminal. 
     
     
       31. The method of claim 30, wherein the handover request message further includes system information used for connecting the target base station to the terminal before the terminal establishes the radio connection with the target base station using a random access channel. 
     
     
       32. 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 that has determined that a handover should occur to a target base station;   wherein the handover command message includes preamble information for the terminal previously defined in a handover confirm message sent from the target base station to the source base station, the preamble information used to avoid a collision with other terminals;   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 a preamble transmission based on the preamble information; and   transmitting, by the terminal, a handover complete message to the target base station.   
     
     
       33. The method of claim 32, wherein a handover decision is based upon measurement information that includes channel conditions. 
     
     
       34. The method of claim 32, wherein the target base station is a base station located in a cell with improved channel conditions. 
     
     
       35. The method of claim 32, wherein the handover command message includes a handover command with a terminal identification, and wherein the target base station determines the terminal identification using the preamble information. 
     
     
       36. The method of claim 32, wherein the handover command message includes time and frequency information for use in connecting the target base station and the terminal. 
     
     
       37. The method of claim 32, wherein the preamble information is used only for the terminal during a random access channel transmission by the terminal. 
     
     
       38. The method of claim 32, wherein the handover command message further includes system information used for connecting the target base station to the terminal before the terminal establishes the radio connection with the target base station using a random access channel. 
     
     
       39. The method of claim 38, wherein the terminal establishes the radio connection without reading the system information of the target base station. 
     
     
       40. The method of claim 38, wherein the radio connection between the target base station and the terminal further includes the target base station receiving the preamble and identifying the terminal based in part on the preamble.