Too bad that neither the lawyers nor the judges understood that bit rate and signal strength are parameters that are directly affected by proximity. In other words, if you drift too far from the access point, your bit rate and signal strength will drop. Therefore, you can use bit rate and signal strength to determine approximate distance (the patent refers to range because you cannot correlate a specific signal strength value to an exact distance). For WiFi, bit rate and signal strength values go to near zero when the device is over 100 meters from the access point.
It is also a shame that the Calypso lawyers did not point out that T-Mobile phones, when out of range of the access point, say something to the effect of "your call has dropped because you have traveled outside the range of the access point" indicating the correlation between signal strength and distance.
