Method and apparatus for performing neighbor tracking in a wireless local area network

1. A method comprising the steps of:

at a subscriber unit:

obtaining a set of access point identifiers and measurement opportunity information for each access point identifier;

performing a first measurement on a first access point identified from the set of access point identifiers;

determining a current timer value after completing the step of performing;

selecting a second access point identified from the set of access point identifiers in which to perform a second measurement, wherein the step of selecting is based on at least the measurement opportunity information for the second access point in relation to the current timer value; and

obtaining a measurement opportunity interval value for each access point identifier, and wherein the measurement opportunity information is a timing offset which is calculated by taking a difference between a timing synchronization function time of the subscriber unit and a timing synchronization function time of an access point, and then taking a modulo of the difference and the measurement opportunity interval value.

2. The method of claim 1 wherein the steps of claim 1 are performed by a wireless local area network module residing in the subscriber unit.

3. The method of claim 1 wherein the set of access point identifiers and the measurement opportunity information for each access point identifier is obtained by a wireless local area network module from a host processor in the subscriber unit.

4. A method comprising the steps of:

at a subscriber unit:

obtaining a set of access point identifiers and measurement opportunity information for each access point identifier;

performing a first measurement on a first access point identified from the set of access point identifiers;

determining a current timer value after completing the step of performing;

selecting a second access point identified from the set of access point identifiers in which to perform a second measurement, wherein the step of selecting is based on at least the measurement opportunity information for the second access point in relation to the current timer value;

selecting a power transition profile based on at least a time difference between the current timer value and an estimated transmission time of a next measurement opportunity for the second access point, wherein the estimated transmission time is derived from the measurement opportunity information for the second access point identifier;

wherein a difference between the current timer value and the estimated transmission time of the next measurement opportunity for the second access point is calculated by subtracting from a measurement opportunity interval value for the second access point a time that has passed since a transmission time of a last measurement opportunity for the second access point; and wherein the time that has passed since the last measurement opportunity is calculated by taking a sum of a timing synchronization function time of the subscriber unit and a timing offset, and then taking a modulo of the sum and the measurement opportunity interval value.

5. A method comprising the steps of:

at a subscriber unit:

obtaining a set of access point identifiers and measurement opportunity information for each access point identifier;

performing a first measurement on a first access point identified from the set of access point identifiers;

determining a current timer value after completing the step of performing;

selecting a second access point identified from the set of access point identifiers in which to perform a second measurement, wherein the step of selecting is based on at least the measurement opportunity information for the second access point in relation to the current timer value; and

wherein the time that has passed since the last measurement opportunity is calculated by taking a difference between a timing synchronization function time of the subscriber unit and a timing synchronization function time of the subscriber unit when a measurement opportunity is transmitted by the second access point, and then taking a modulo of the sum and the measurement opportunity interval value.

6. The method of claim 1 wherein the steps of claim 1 are implemented by a state machine.

7. The method of claim 1 wherein the first and second measurements are taken from a broadcast measurement frame transmitted by the first and second access points, respectively.