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 communicationmethodfor Random Access (RA) in a communication system, the method comprising:
 receivingRA, at a base station, Random Access (RA) preambles from a plurality of terminals; and 
 generating, at the base station, an RA response message; and  
 transmittingan, at the base station, the RA response messageto the plurality of terminals, 
 wherein the RA response message includes:
 common information for the plurality of terminals, wherein the common information comprises overload condition informationwith respect to the RA of the plurality of terminals; 
 a plurality of RA preamble indicatorsrespectively indicating each RA preamble from each terminal; and 
 a plurality of RA responsesrespectively corresponding to each terminal, 
 
 wherein the common information including 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 further includes an information discrimination field indicating that the overload condition information is included;, 
 and wherein the overload condition information includes comprises a back off time informationfor the plurality of the terminals. 
 
     
     
       2. The method of  claim 1 , wherein each of the plurality of RA response responses comprises uplink timing information, and 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 communication methodfor Random Access (RA) of a first terminal in a communication system, the method comprising:
 transmittingan RA, 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 terminalsattempting RA to the base station, wherein the common information comprises overload condition informationwith 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 indicatorsrespectively corresponding to the second terminals; 
 first RA response corresponding to the first terminal; 
 and a plurality of RA responsesrespectively corresponding to the second terminals, 
 
 wherein the common information including 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 further includes an information discrimination field indicating that the overload condition information is included;, 
 and wherein the overload condition information includes comprises a back off time informationfor the first terminal and the second terminals. 
 
     
     
       8. The method of  claim 7 , wherein each of the first plurality of RA response responses comprises uplink timing information, and 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 apparatus, 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 communication apparatus to receive Random Access (RA) preambles from a plurality of terminals; 
 generate an RA response message; and 
 transmit the RA response message, 
 wherein the RA response message includes:
 common information for the plurality of 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 further includes an information discrimination field indicating that the overload condition information is included, 
 and wherein the overload condition information comprises a back off time information. 
 
   
     
     
       11. The communication apparatus of claim 10, wherein each of the plurality of RA responses comprises uplink timing information and uplink allocation information. 
     
     
       12. The communication apparatus 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. 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 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 further includes an information discrimination field indicating that the overload condition information is included,   and wherein the overload condition information comprises a back off time information.   
     
     
       14. The terminal of claim 13, wherein each of the plurality of RA responses comprises uplink timing information and uplink allocation information. 
     
     
       15. The terminal of claim 14, 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. 
     
     
       16. A communication device for 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 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 further includes an information discrimination field indicating that the overload condition information is included,   and wherein the overload condition information comprises a back off time information.   
     
     
       17. The communication device of claim 16, wherein each of the plurality of RA responses comprises uplink timing information and uplink allocation information. 
     
     
       18. The communication device 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.