Method for signaling back-off information in random 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.

What is claimed is: 
     
       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) Medium Access Control (MAC) header and zero or more not having any MAC Random Access Responses (MAC RARs) Response (MAC RAR); 
 determining if that 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 based on determining that 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 MAC RAR corresponding MAC RAR to the MAC sub-header that has the backoff parameter in the random access response message when the field in the MAC sub-header indicates the backoff parameter exists in the, and 
 wherein there is only one MAC sub-header that has the backoff parameter in the MAC 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 station. 
     
     
       4. The method of  claim 1 , wherein the field in the MAC sub-header is followed by the backoff parameter. 
     
     
       5. The method of  claim 4 , wherein the field in the MAC sub-header 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) Medium Access Control (MAC) header and zero or more not having any MAC Random Access Responses (MAC RARs) Response (MAC RAR), wherein a MAC sub-header of 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 that 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 based on determining that the field in the MAC sub-header indicates the backoff parameter exists in the MAC sub-header; and 
 performing, by the mobile terminal, the backoff using the backoff parameter obtained from the MAC sub-header, 
 wherein there is no MAC RAR corresponding MAC RAR to the MAC sub-header that has the backoff parameter in the random access response message when the field in the MAC sub-header indicates the backoff parameter exists in the, and 
 wherein there is only one MAC sub-header that has the backoff parameter in the MAC 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, the mobile terminal 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) Medium Access Control (MAC) header and zero or more not having any MAC Random Access Responses (MAC RARs) Response (MAC RAR); 
 determine if that 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 based on determining that the field in the MAC sub-header indicates the backoff parameter exists in the MAC sub-header; and 
 perform backoff using the backoff information parameter obtained from the MAC sub-header, 
 wherein there is no MAC RAR corresponding MAC RAR to the MAC sub-header that has the backoff parameter in the random access response message when the field in the, and 
 wherein there is only one MAC sub-header indicates that has the backoff parameter exists in the in the MAC sub-header 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  13, wherein the field in the MAC sub-header indicating the backoff parameter is directly followed by the backoff parameter. 
     
     
       17. The mobile terminal of  claim 16 , wherein the field in the MAC sub-header indicating the backoff parameter is directly 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 node configured to perform a random access procedure in a wireless communication system, the network node comprising:
 a processor configured to cause the network node 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) Medium Access Control (MAC) header and zero or more not having any MAC Random Access Responses (MAC RARs) Response (MAC RAR), 
 wherein a MAC sub-header of 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 MAC RAR corresponding MAC RAR to the MAC sub-header that has the backoff parameter in the random access response message when the field in the MAC sub-header indicates the backoff parameter exists in the, and 
 wherein there is only one MAC sub-header that has the backoff parameter in the MAC header. 
 
     
     
       20. The network node 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 node of  claim 19 , wherein the backoff information parameter is a common backoff parameter or an exclusive backoff parameter to be used exclusively by the mobile terminal. 
     
     
       22. The network node of  claim 19 , wherein the field in the MAC sub-header indicates the backoff parameter exists in the MAC sub-header, and the field is followed by the backoff parameter. 
     
     
       23. The network node of  claim 22 , wherein the field in the MAC sub-header indicates the backoff parameter exists in the MAC sub-header, and the field is directly followed by the back-off backoff parameter. 
     
     
       24. The method network node 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 node.