Patent ID: 7389052

Claim:
A method for providing a common coordinate basis between two optical wireless units wherein information is transmitted between the optical wireless units via light beams, the method comprising: at the first optical wireless unit: moving the light beam in a first prespecified pattern; receiving detector range data from the second optical wireless unit; and moving the light beam in a second prespecified pattern; at the second optical wireless unit: determining detector range; transmitting the detector range; determining reference positions; generating a table of detector readings; and wherein the first prespecified pattern is a spiral pattern with a specified number of revolutions, first determining step comprising: calculating a signal strength metric for each revolution; maintaining a maximum signal strength; comparing the signal strength metric with a threshold; setting a radius of dynamic range of a search pattern about remote detectors at the second optical wireless unit if the signal strength metric is less than the threshold; and transmitting the radius to the first optical wireless unit.