Apparatus and method for random access in cellular system

Abstract

Disclosed is a method and apparatus for RA in a cellular system. The RA in the cellular system includes receiving an RA preamble from a terminal for RA, transmitting, to the terminal, an RA response message including a sequence of the received RA preamble and uplink resource information of the terminal and overload state information with respect to the RA, receiving control information generated based on the RA response message from the terminal through the uplink resource information, and transmitting control response information with respect to the received control information.

The invention claimed is: 
     
         1 . A method for Random Access (RA) in a communication system, the method comprising:
 receiving RA preambles from a plurality of terminals; and transmitting an RA response message to the plurality of terminals, wherein the RA response message includes:   common information for the plurality of terminals wherein the common information comprises overload condition information with respect to the RA of the plurality of terminals;   a plurality of RA preamble indicators respectively indicating each RA preamble from each terminal; and   a plurality of RA responses respectively corresponding to each terminal, wherein the common information including the overload condition information in the RA response message is distinct from the plurality of RA preamble indicators and the plurality of RA responses, and the RA response message further includes an information discrimination field indicating that the overload condition information is included;   wherein the overload condition information includes a back off time information for the plurality of the terminals.   
     
     
         2 . The method of  claim 1 , wherein each RA response comprises uplink timing information, uplink allocation information, and temporary terminal identifier. 
     
     
         3 . The method of  claim 2 , wherein the uplink allocation information indicates uplink resource to be used on the uplink transmission and further indicates modulation and coding scheme for the uplink resource. 
     
     
         4 . The method of  claim 1 , wherein the RA response message includes:
 the common information comprising the overload condition information;   first RA preamble indicator corresponding to a first terminal among the terminals;   second RA preamble indicator corresponding to a second terminal among the terminals;   first RA response corresponding to the first terminal; and   second RA response corresponding to the second terminal.   
     
     
         5 . The method of  claim 4 , wherein the first RA response comprises first uplink timing information, first uplink allocation information, and first temporary terminal identifier corresponding to the first terminal and the second RA response comprises second uplink timing information, second uplink allocation information, and second temporary terminal identifier corresponding to the second terminal. 
     
     
         6 . The method of  claim 1 , wherein the RA response message further includes preamble existence field indicating if additional RA preamble indicator exists or not. 
     
     
         7 . A method for Random Access (RA) of a first terminal in a communication system, the method comprising:
 transmitting an RA preamble to a base station; and   receiving an RA response message from the base station, wherein the RA response message includes: common information for the first terminal and second terminals attempting RA to the base station wherein the common information comprises overload condition information with respect to the RA of the first terminal and the second terminals;   first RA preamble indicator corresponding to the first terminal; a plurality of RA preamble indicators respectively corresponding to the second terminals;   first RA response corresponding to the first terminal; and a plurality of RA responses respectively corresponding to the second terminals, wherein the common information including the overload condition information in the RA response message is distinct from the plurality of RA preamble indicators and the plurality of RA responses, and the RA response message further includes an information discrimination field indicating that the overload condition information is included;   wherein the overload condition information includes a back off time information for the first terminal and the second terminals.   
     
     
         8 . The method of  claim 7 , wherein the first RA response comprises uplink timing information, uplink allocation information, and temporary terminal identifier for the first terminal. 
     
     
         9 . The method of  claim 8 , wherein the uplink allocation information indicates uplink resource to be used on the uplink transmission and further indicates modulation and coding scheme for the uplink resource. 
     
     
       10. A communication method, the method comprising:
 transmitting, at a first terminal, a Random Access (RA) preamble to a base station; and   receiving, at the first terminal, an RA response message from the base station,   wherein the RA response message includes:   common information for the first terminal and second terminals, wherein the common information comprises overload condition information;   a plurality of RA preamble indicators;   and a plurality of RA responses,   wherein the common information comprising the overload condition information in the RA response message is distinct from the plurality of RA preamble indicators and the plurality of RA responses, and the RA response message includes a first field indicating that the overload condition information is included, and   wherein the overload condition information comprises back off time information.   
     
     
       11. The method of  claim 10 , wherein each of the plurality of RA responses comprises uplink timing information and uplink allocation information. 
     
     
       12. The method of  claim 11 , wherein the uplink allocation information indicates uplink resource to be used on uplink transmission and further indicates modulation and coding scheme for the uplink resource. 
     
     
       13. The method of  claim 10 , wherein each of the plurality of RA responses identifies one of the first terminal and the second terminals. 
     
     
       14. The method of  claim 10 , wherein one of the plurality of RA responses comprises a temporary terminal identifier of the first terminal. 
     
     
       15. The method of  claim 10 , wherein each of the plurality of RA responses comprises a temporary terminal identifier of one of the first terminal and the second terminals. 
     
     
       16. A terminal, comprising:
 a memory; and   a processor, operably coupled to the memory,   wherein the processor, when executing program instructions stored in the memory, is configured to:
 cause the terminal to transmit a Random Access (RA) preamble to a base station; and 
 cause the terminal to receive an RA response message from the base station, wherein the RA response message includes: 
   common information for the terminal and other terminals, wherein the common information comprises overload condition information;   a plurality of RA preamble indicators;   and a plurality of RA responses,   wherein the common information comprising the overload condition information in the RA response message is distinct from the plurality of RA preamble indicators and the plurality of RA responses, and the RA response message includes a first field indicating that the overload condition information is included, and   wherein the overload condition information comprises back off time information.   
     
     
       17. The terminal of  claim 16 , wherein each of the plurality of RA responses comprises uplink timing information and uplink allocation information. 
     
     
       18. The terminal of  claim 17 , wherein the uplink allocation information indicates uplink resource to be used on uplink transmission and further indicates modulation and coding scheme for the uplink resource. 
     
     
       19. The terminal of  claim 16 , wherein each of the plurality of RA responses identifies one of the terminal and the other terminals. 
     
     
       20. The terminal of  claim 16 , wherein one of the plurality of RA responses comprises a temporary terminal identifier of the terminal. 
     
     
       21. The terminal of  claim 16 , wherein each of the plurality of RA responses comprises a temporary terminal identifier of one of the terminal and the other terminals. 
     
     
       22. A communication device for a terminal, the communication device comprising:
 a memory; and   a processor, operably coupled to the memory,   wherein the processor, when executing program instructions stored in the memory, is configured to:
 cause the terminal to transmit a Random Access (RA) preamble to a base station; and 
 cause the terminal to receive an RA response message from the base station, wherein the RA response message includes: 
   common information for the terminal and other terminals, wherein the common information comprises overload condition information;   a plurality of RA preamble indicators;   and a plurality of RA responses,   wherein the common information comprising the overload condition information in the RA response message is distinct from the plurality of RA preamble indicators and the plurality of RA responses, and the RA response message includes a first field indicating that the overload condition information is included, and   wherein the overload condition information comprises back off time information.   
     
     
       23. The communication device of  claim 22 , wherein each of the plurality of RA responses comprises uplink timing information and uplink allocation information. 
     
     
       24. The communication device of  claim 23 , wherein the uplink allocation information indicates uplink resource to be used on uplink transmission and further indicates modulation and coding scheme for the uplink resource. 
     
     
       25. The communication device of  claim 22 , wherein each of the plurality of RA responses identifies one of the terminal and the other terminals. 
     
     
       26. The communication device of  claim 22 , wherein one of the plurality of RA responses comprises a temporary terminal identifier of the terminal. 
     
     
       27. The communication device of  claim 22 , wherein each of the plurality of RA responses comprises a temporary terminal identifier of one of the terminal and the other terminals.