Channel assignment method for a base station in a mobile communication system

Abstract

There is disclosed a method for performing channel assignment in a base station for a mobile communication system. Upon receipt of a request for assigning a channel to a mobile station, a base station transceiver system (BTS) generates a connect message including channel information, which indicates a Walsh code, out of 256 Walsh codes, to be used for a channel to be assigned to the mobile station, and a quasi-orthogonal function (QOF) index. The BTS transmits the generated connect message to a base station controller (BSC). The BSC generates a connect ACK message for acknowledging the channel assignment-related information included in the connect message and transmits the generated connect ACK message to the BTS. Upon receipt of the connect ACK message, in the BTS assigns the channel that was acknowledged by the BSC to the mobile station.

1. A method for performing channel assignment in a base station for a mobile communication system, comprising the steps of:
 generating, in a base station transceiver system (BTS), a connect message upon receipt of a request for assigning a channel to a mobile station, said connect message including channel information indicating a Walsh code, out of 256 Walsh codes, to be used for a channel to be assigned to the mobile station, and a quasi-orthogonal function (QOF) index;  
 transmitting the generated connect message to a base station controller (BSC);  
 generating, in the BSC, a connect ACK (acknowledge) message for acknowledging channel assignment-related information included in the connect message;  
 transmitting the generated connect ACK message to the BTS; and  
 assigning, in the BTS, a channel to the mobile station, said channel having been acknowledged by the BSC, upon receipt of the connect ACK message.  
 
     
     
       2. The method as claimed in  claim 1 , wherein four quasi-orthogonal functions are provided. 
     
     
       3. The method as claimed in  claim 1 , wherein the channel information is comprised of 8 or 11 bits. 
     
     
       4. The method as claimed in  claim 1 , wherein the step of generating the connect message comprises the steps of:
 designating a frame selector (or channel type) in the connect message to indicate a supplemental code channel (SCCH) and designating a Walsh code with 6-bit channel information, if the channel to be assigned to the mobile station is a supplemental code channel (SCCH); and  
 ignoring overlapped information elements due to establishment of a fundamental channel in the connect message and filling in the remaining information fields in the connect message.  
 
     
     
       5. The method as claimed in  claim 1 , wherein the step of generating the connect message comprises the steps of:
 determining whether to perform QOF masking on the channel to be assigned to the mobile station;  
 designating, if it is determined that QOF masking should be performed, the channel information indicating a Walsh code, out of 256 Walsh codes, to be used for a channel to be assigned to the mobile station, and designating the QOF index indicating a quasi-orthogonal function to be used for QOF masking;  
 filling in the remaining information fields of the connect message; and transmitting the connect message to the BSC.  
 
     
     
       6. The method as claimed in  claim 1 , wherein the step of generating the connect message comprises the steps of:
 determining whether to perform QOF masking on the channel to be assigned to the mobile station;  
 designating, if it is determined that QOF masking should not be performed, the channel information indicating the Walsh code, out of 256 Walsh codes, to be used for a channel to be assigned to the mobile station, and setting the QOF index to ‘00’;  
 filling in the remaining information fields of the connect message; and  
 transmitting the connect message to the BSC.  
 
     
     
       7. The method as claimed in  claim 1 , wherein the connect message is an A 3  interface message transmitted when a target base station initiates or adds one or more A 3  interface user traffic connections to a SDU (Selection/Distribution Unit) of the source base station. 
     
     
       8. A method for performing channel assignment in a base station for a mobile communication system, comprising the steps of:
   transmitting, from a base station transceiver system  ( BTS )  to a base station controller  ( BSC ),  a connect message upon receipt of a request for assigning a channel to a mobile station, said connect message including channel information indicating a Walsh code, out of  256  Walsh codes, to be used for a channel to be assigned to the mobile station, and a quasi - orthogonal function  ( QOF )  index;        transmitting, from the BSC to the BTS, a connect ACK  ( acknowledge )  message for acknowledging channel assignment - related information included in the connect message; and        assigning, in the BTS, a channel to the mobile station, said channel having been acknowledged by the BSC, upon receipt of the connect ACK message.     
     
     
       9. The method as claimed in  claim 8 , wherein four quasi- orthogonal functions are provided.   
     
     
       10. The method as claimed in  claim 8 , wherein the channel information is comprised of  8  or  11  bits. 
     
     
       11. The method as claimed in  claim 8 , wherein the connect message is an A 3  interface message transmitted when a target base station initiates or adds one or more A 3  interface user traffic connections to a SDU ( Selection/Distribution Unit )  of the source base station.   
     
     
       12. The method as claimed in  claim 8 , further comprising the steps of:
   designating a frame selector  ( or channel type )  in the connect message to indicate a supplemental code channel  ( SCCH )  and designating a Walsh code with  6   - bit channel information, if the channel to be assigned to the mobile station is a supplemental code channel  ( SCCH );  and        ignoring overlapped information elements due to establishment of a fundamental channel in the connect message and filling in the remaining information fields in the connect message.     
     
     
       13. The method as claimed in  claim 8 , further comprising the steps of:
   determining whether to perform QOF masking on the channel to be assigned to the mobile station;        designating, if it is determined that QOF masking should be performed, the channel information indicating a Walsh code, out of  256  Walsh codes, to be used for a channel to be assigned to the mobile station, and designating the QOF index indicating a quasi - orthogonal function to be used for QOF masking;        filling in the remaining information fields of the connect message; and transmitting the connect message to the BSC.     
     
     
       14. The method as claimed in  claim 8 , further comprising the steps of:
   determining whether to perform QOF masking on the channel to be assigned to the mobile station;        designating, if it is determined that QOF masking should not be performed, the channel information indicating the Walsh code, out of  256  Walsh codes, to be used for a channel to be assigned to the mobile station, and setting the QOF index to ‘ 00 ’;        filling in the remaining information fields of the connect message; and        transmitting the connect message to the BSC.     
     
     
       15. A apparatus for performing channel assignment in a base station for a mobile communication system, comprising:
   a base station transceiver system  ( BTS )  for transmitting a connect message upon receipt of a request for assigning a channel to a mobile station, said connect message including channel information indicating a Walsh code, out of  256  Walsh codes, to be used for a channel to be assigned to the mobile station, and a quasi - orthogonal function  ( QOF )  index;        a base station controller  ( BSC )  for receiving the connect message and transmitting to a connect ACK  ( acknowledge )  message for acknowledging channel assignment - related information included in the connect message to the BTS;        wherein the BTS assigns the channel to the mobile station, said channel having been acknowledged by the BSC, upon receipt of the connect ACK message.     
     
     
       16. The apparatus as claim in  claim 15 , wherein four quasi- orthogonal functions are provided.   
     
     
       17. The apparatus as claim in  claim 15 , wherein the channel information is comprised of  8  or  11  bits. 
     
     
       18. The apparatus as claimed in  claim 15 , wherein the connect message is an A 3  interface message transmitted when a target base station initiates or adds one or more A 3  interface user traffic connections to a SDU ( Selection/Distribution Unit )  of the source base station.