METHOD OF TRANSMITTING AND RECEIVING RADIO ACCESS INFORMATION IN A WIRELESS MOBILE COMMUNICATIONS SYSTEM

• US 20070047493A1
• Filed: 10/27/2006
• Published: 03/01/2007
• Est. Priority Date: 10/31/2005
• Status: Active Grant

• Current Assignee: Evolved Wireless LLC
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Park, Sung Jun, Lee, Young, Jung, Myung, Chun, Sung
• Granted Patent: US 7,809,373 B2
• Time in Patent Office: Days
• US Class Current: 370/331
• CPC Class Codes: H04L 17/00 Apparatus or local circuits for transmitting or receiving codes wherein each character is represented by the same number of equal-length code elements, e.g. Baudot code
• CPC Class Codes: H04L 7/00 Arrangements for synchronising receiver with transmitter synchronisation of generators of electric oscillations or pulses H03L7/00
• CPC Class Codes: H04W 36/0055 Transmission or use of information for re-establishing the radio link
• CPC Class Codes: H04W 36/0058 Transmission of hand-off measurement information, e.g. measurement reports
• CPC Class Codes: H04W 74/002 Transmission of channel access control information
• CPC Class Codes: H04W 74/006 in the downlink, i.e. towards the terminal

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.

Claims

1. A method of transmitting access information in a mobile communications system, the method comprising:

deciding to perform a handover for a terminal to a cell of a target base station;

transmitting, to the target base station, a handover request for performing a handover from a source base station to the target base station; and

receiving access information from the target base station that received the handover request, wherein the access information is then transmitted to the terminal to access the target base station.

2. The method of claim 1, further comprising:

receiving a measurement report from the terminal.

3. The method of claim 2, wherein the measurement report includes a downlink physical channel condition for multiple cells including the cell of the target base station.

4. The method of claim 3, further comprising:

determining whether to perform a handover based upon the received measurement report.

5. The method of claim 1, wherein the handover request includes at least one of terminal identification (ID) information and/or buffer state information of the terminal.

6. The method of claim 1, wherein the access information is random access information.

7. The method of claim 11 wherein the access information is for a random access channel (RACH).

8. The method of claim 1, wherein the access information includes at least one of signature information and/or preamble information.

9. The method of claim 8, wherein the signature information is determined by the target base station based upon terminal identification information.

10. The method of claim 8, wherein the preamble information includes frequency information and time information.

11. The method of claim 1, further comprising:

transmitting a handover command that contains the access information to the terminal upon receiving the response by the source base station.

12. The method of claim 11, wherein the handover command includes access information which contains at least one of signature information and/or preamble information to allow the terminal to access the target base station.

13. A method of transmitting access information in a mobile communications system, the method comprising:

receiving, from a source base station, a handover request for performing a handover from the source base station to a target base station; and

transmitting access information to the source base station upon receiving the handover request, wherein the access information is used to allow a terminal to access the target base station.

14. The method of claim 13, further comprising:

allocating a radio resource for an uplink and transmitting radio resource allocation information to the terminal.

15. The method of claim 14, wherein the radio resource allocation information is transmitted to the terminal through at least one of a downlink shared channel (SCH) and a downlink shared control channel (SCCH).

16. The method of claim 15, wherein an ACK/NACK signal includes the allocated resource information.

17. The method of claim 13, further comprising:

receiving, from the terminal, preamble information of the terminal.

18. The method of claim 17, wherein the preamble information is used to identify the terminal.

19. The method of claim 13, further comprising:

receiving a handover complete message from the terminal.

20. The method of claim 19, wherein the handover complete message includes at least one of buffer state information of the terminal and uplink traffic data.

21. The method of claim 19, wherein the handover complete message includes uplink traffic data if the radio resource allocation for the uplink is sufficient to transmit the uplink traffic data.

22. A method of receiving access information in mobile communications system, the method comprising:

receiving access information from a source base station after a handover is accepted by a target base station; and

performing a random access procedure with the target base station using the received access information.

23. The method of claim 22, further comprising:

transmitting a measurement report to the source base station by measuring a condition of a downlink physical channel for other cells, the measuring performed periodically or upon an occurrence of an event.

24. The method of claim 23, wherein the measurement report is used to determine whether to perform a handover from a current cell to an other cell.

25. The method of claim 22, wherein the access information is random access information for a random access channel (RACH) which includes preamble information within signature information.

26. The method of claim 25, further comprising:

transmitting the preamble information to the target base station for performing a radio access procedure with the target cell.

27. The method of claim 25, wherein the access information includes a transmission characteristic of the preamble information, the transmission characteristic relates to frequency and time used in transmitting the preamble information.

28. The method of claim 22, wherein the access information includes system information transmitted from the target base station.

29. The method of claim 22, further comprising:

receiving, from a network, radio resource information through a downlink shared channel (SCCH).

30. The method of claim 22, further comprising:

receiving, from a network, radio resource information within an ACK/NACK signaling.

31. The method of claim 22, further comprising:

transmitting a handover complete message to the target base station.

32. The method of claim 31, wherein the handover complete message includes at least one of buffer state information of the terminal and uplink traffic data.

33. A mobile terminal for establishing a radio connection to a target base station in a mobile communications system, the mobile terminal comprising:

a radio protocol adapted to receive access information from a source base station after a handover is accepted by the target base station and to perform a random access procedure with the target base station using the received access information.

34. The terminal of claim 33, wherein the source base station is a source enhanced Node B (source eNB) and the target base station is a target enhanced Node B (target eNB) respectively in an Evolved Universal Mobile Telecommunication System (E-UMTS).