Method and apparatus for identifying supported transmission channel configurations

1. A method for identifying supported transmission channel configurations in a mobile communications apparatus, the method comprising:

pre-calculating the required power value for each transmission channel configuration using a value of the mobile communications apparatus maximum transmit power and a gain relationship, the gain relationship being a ratio of a gain for the transmission channel configuration data channel with gain for the transmission channel configuration control channel; and

performing a sequential comparison of:

an indication of an available measured power value calculated from a measurement of transmit power of a particular preceding transmission interval and using a gain relationship of the transmission channel configuration used during the particular preceding transmission interval, and

an indication of the required power for each transmission channel configuration; and

identifying a particular transmission channel configuration as supported if the required power for the particular transmission channel configuration is less than the available power value;

wherein:

the transmission channel configurations are arranged in descending order of the indication of required power;

the sequential comparison is performed in descending order of magnitude of value of the indication of the required power; and

the method further comprising stopping said comparison when a supported transmission channel configuration is identified.

2. The method as claimed in claim 1 , wherein the gain relationship is derived from a signaled gain factor or a computed gain factor.

3. The method as claimed claim 1 , wherein the sequential comparison is performed in order of the transmission channel configuration having the greatest power requirement first.

4. The method as claimed in claim 1 , wherein the transmission channel configurations are transport format combinations.

5. The method as claimed in claim 1 , wherein the mobile communications apparatus is a user equipment in a universal mode telecommunications system network.

6. The method as claimed in claim 1 , wherein the step of pre-calculating comprises calculating and storing.

7. The method as claimed in claim 1 , wherein the step of pre-calculating is performed at reconfiguration of the mobile communications apparatus.

8. A mobile communications apparatus arranged to perform the method of claim 1 .

9. A computer program product comprising code means stored on a non-transitory computer readable medium for performing the steps of the method of claim 1 .

10. A computer operating under the instructions of a computer program product comprising code means stored on a non-transitory computer readable medium for performing the steps of the method of claim 1 .

11. A mobile communications apparatus arranged to perform the method of claim 1 .

12. A computer program product comprising code means stored on a non-transitory computer readable medium for performing the steps of the method of claim 1 .

13. A computer operating under the instructions of a computer program product comprising code means stored on a non-transitory computer readable medium for performing the steps of the method of claim 1 .