System, method, and apparatus for establishing headroom for a mobile station

1. A method for establishing headroom to provide margin in determining available transmit power value for a mobile station operating in a wireless communication system comprising the steps of:

determining, by the mobile station, a communication channel variance condition, wherein the communication channel variance condition is at least one of a primary pilot power variance, fading period and fade depth estimate, or a peak-to-average estimate within an adaptive measurement interval; and

establishing, by the mobile station, a headroom value based on the communication channel variance condition.

2. A method according to claim 1 wherein the mobile station determines a maximum data rate based on the headroom value and sends the maximum data rate to a base station.

3. A method according to claim 1 wherein the mobile station determines a maximum data rate based on the headroom value and sends a rate adjustment request to a base station.

4. A method according to claim 1 further comprising the steps of:

detecting a battery condition of the mobile station; and

modifying the headroom value based on the battery condition.

5. A method according to claim 4 wherein the step of modifying the headroom value based on the battery condition comprises:

determining if the battery condition relates to a low battery level; and

if the battery condition relates to a low battery level, increasing the headroom value.

6. A method according to claim 1 wherein the step of determining a communication channel variance condition includes measuring a variance in a primary pilot power.

7. A mobile station comprising:

means for determining, by the mobile station, a communication channel variance condition, wherein the communication channel variance condition is at least one of a primary pilot power variance, fading period and fade depth estimate, or a peak-to-average estimate within an adaptive measurement interval; and

means for establishing, by the mobile station, a headroom value based on the communication channel variance condition.

8. A mobile station according to claim 7 further comprising:

means for determining a maximum data rate based on the headroom value; and

means for sending the maximum data rate to a base station.

9. A mobile station according to claim 7 further comprising:

means for determining a maximum data rate based on the headroom value; and

means for sending a rate adjustment request to a base station.

10. A mobile station according to claim 7 further comprising:

means for detecting a battery condition of the mobile station; and

means for modifying the headroom value based on the battery condition.

11. A wireless communication system comprising:

a base station;

at least one mobile station;

means for determining, by the at least one mobile station, a communication channel variance condition, wherein the communication channel variance condition is at least one of a primary pilot power variance, fading period and fade depth estimate, or a peak-to-average estimate within an adaptive measurement interval; and

means for establishing, by the at least one mobile station, a headroom value based on the communication channel variance condition.

12. A wireless communication system according to claim 11 further comprising:

means for determining a data rate based on the headroom value.

13. A wireless communication system according to claim 12 further comprising:

means for sending the data rate between the base station and said at least one mobile station.

14. A wireless communication system according to claim 11 further comprising:

means for determining a battery condition of said at least one mobile station; and

means for modifying the headroom value based on the battery condition.

15. A wireless communication system according to claim 14 further comprising:

means for determining a data rate based on the headroom value; and

means for sending the data rate between said at least one mobile station and the base station.