Method for signaling back-off information in random access

• US 8,040,913 B2
• Filed: 05/29/2009
• Issued: 10/18/2011
• Est. Priority Date: 01/31/2008
• Status: Expired

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Chun, Sung Duck, Park, Sung Jun, Lee, Young Dae, Yi, Seung June
• Primary Examiner(s): Ngo; Ricky
• Assistant Examiner(s): KAO, WEI PO ERIC
• Application Number:
  US12/475,107
• Publication Number:
  US 20090232058A1
• Time in Patent Office: 872 Days
• Field of Search: 370/328, 370/445, 370/447, 370/448, 370/462
• US Class Current: 370/445
• CPC Class Codes: H04W 74/002 Transmission of channel access control information
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

A method for performing random access in a wireless communication system is provided. The method includes transmitting a preamble for random access in uplink, receiving a random access response message including back-off information as a response to the preamble, and performing back-off using the back-off information when the random access has failed.

Claims

1. A method for performing a random access procedure in a wireless communication system, the method comprising:

transmitting a first preamble for random access from a mobile station to a network;

receiving by the mobile station a random access response message from the network as a response to the first preamble, the random access response message having a MAC (Medium Access Control) header and zero or more MAC Random Access Responses (MAC RARs);

determining if a field in a MAC sub-header of the MAC header indicates a backoff parameter exists in the MAC sub-header;

obtaining the backoff parameter from the MAC sub-header when the field in the MAC sub-header indicates the backoff parameter exists in the MAC sub-header; and

performing backoff using the backoff parameter obtained from the MAC sub-header,

wherein there is no corresponding MAC RAR in the random access response message when the field in the MAC sub-header indicates the backoff parameter exists in the MAC sub-header.

2. The method of claim 1, wherein the field indicates whether or not the MAC sub-header has a random access preamble identifier or the backoff parameter.

3. The method of claim 1, wherein the backoff parameter is a common backoff parameter or an exclusive backoff parameter to be used exclusively by the mobile terminal.

4. The method of claim 1, wherein the field is followed by the backoff parameter.

5. The method of claim 4, wherein the field is directly followed by the backoff parameter.

6. The method of claim 1, wherein the backoff parameter is related with a transmission of a second preamble for random access.

7. A method for performing a random access procedure in a wireless communication system, the method comprising:

receiving at a network a first preamble for random access from a mobile terminal;

transmitting by the network a random access response message to the mobile terminal as a response to the first preamble, the random access response message having a MAC (Medium Access Control) header and zero or more MAC Random Access Responses (MAC RARs), wherein the MAC header comprises a MAC sub-header including a field indicating whether or not the MAC sub-header has a backoff parameter configured to enable the mobile terminal to perform backoff;

determining, by the mobile terminal, if the field in the MAC sub-header indicates the backoff parameter exists in the MAC sub-header;

obtaining, by the mobile terminal, the backoff parameter from the MAC sub-header when the field in the MAC sub-header indicates the backoff parameter exists in the MAC sub-header; and

performing, by the mobile terminal, backoff using the backoff parameter obtained from the MAC sub-header,

wherein there is no corresponding MAC RAR in the random access response message when the field in the MAC sub-header indicates the backoff parameter exists in the MAC sub-header.

8. The method of claim 7, wherein the field indicates whether or not the MAC sub-header has a random access preamble identifier or the backoff parameter.

9. The method of claim 7, wherein the backoff parameter is common back-off parameter or an exclusive backoff parameter to be used exclusively by the mobile terminal.

10. The method of claim 7, wherein the field is followed by the backoff parameter.

11. The method of claim 10, wherein the field is directly followed by the backoff parameter.

12. The method of claim 7, wherein the backoff parameter is related with a transmission of a second preamble for random access that is to be received by the network.

13. A mobile terminal configured to perform a random access procedure in a wireless communication system, comprising:

a processor configured to cause the mobile terminal to

transmit a first preamble for random access to a network;

process a random access response message received from the network as a response to the first preamble, the random access response message having a MAC (Medium Access Control) header and zero or more MAC Random Access Responses (MAC RARs);

determine if a field in a MAC sub-header of the MAC header indicates a backoff parameter exists in the MAC sub-header;

obtain the backoff parameter from the MAC sub-header when the field in the MAC sub-header indicates the backoff parameter exists in the MAC sub-header; and

perform backoff using the backoff information obtained from the MAC sub-header,

wherein there is no corresponding MAC RAR in the random access response message when the field in the MAC sub-header indicates the backoff parameter exists in the MAC sub-header.

14. The mobile terminal of claim 13, wherein the field indicates whether or not the MAC sub-header has a random access preamble identifier or the backoff parameter.

15. The mobile terminal of claim 13, wherein the backoff parameter is a common backoff parameter or an exclusive backoff parameter to be used exclusively by the mobile terminal.

16. The mobile terminal of claim 15, wherein the field is directly followed by the backoff parameter.

17. The mobile terminal of claim 16, wherein the field is followed by the backoff parameter.

18. The mobile terminal of claim 13, wherein the backoff parameter is related with a transmission of a second preamble for random access.

19. A network configured to perform a random access procedure in a wireless communication system, comprising:

a processor configured to cause the network to process a first preamble for random access received from a mobile terminal; and

to transmit a random access response message to the mobile terminal as a response to the first preamble, the random access response message having a MAC (Medium Access Control) header and zero or more MAC Random Access Responses (MAC RARs),

wherein the MAC header includes a MAC sub-header including a field indicating whether or not the MAC sub-header includes a backoff parameter, and

wherein there is no corresponding MAC RAR in the random access response message when the field in the MAC sub-header indicates the backoff parameter exists in the MAC sub-header.

20. The network of claim 19, wherein the field indicates whether or not the MAC sub-header has a random access preamble identifier or the backoff parameter.

21. The network of claim 19, wherein the backoff information is a common backoff parameter or an exclusive backoff parameter to be used exclusively by the mobile terminal.

22. The network of claim 19, wherein the field is followed by the backoff parameter.

23. The network of claim 22, wherein the field is directly followed by the back-off parameter.

24. The method of claim 19, wherein the backoff parameter is related with a transmission of a second preamble for random access that is to be received by the network.