Proximity determination based on distance ratios

An apparatus for determining proximity of a mobile device to a target location, the apparatus comprising:

• means for identifying a signal sent by the mobile device and received by respective ones of a set of receivers including at least a first receiver and a second receiver, wherein the first receiver and the second receiver are positioned collinearly to the target location;
• means for determining a first signal-quality metric observed at the first receiver and a second signal-quality metric observed at the second receiver with respect to the signal;
• means for computing a ratio associated with distances from the mobile device to the first receiver and the second receiver, respectively, based on the first signal-quality metric and the second signal-quality metric;
• and means for determining whether the mobile device is within a proximity region defined with respect to the target location based on a comparison of the ratio with a ratio constant which is a ratio of a first distance between each point of a set of points of the proximity region surrounding the target location and the first receiver, and a second distance between the each point of the set of points and the second receiver.

A computer program product residing on a non-transitory processor-executable computer storage medium, the computer program product comprising processor-executable instructions configured to cause a processor to:

• identify a signal sent by a mobile device and received by respective ones of a set of receivers including at least a first receiver and a second receiver, wherein the first receiver and the second receiver are positioned collinearly to a target location;
• determine a first signal-quality metric observed at the first receiver and a second signal-quality metric observed at the second receiver with respect to the signal;
• compute a ratio associated with distances from the mobile device to the first receiver and the second receiver, respectively, based on the first signal-quality metric and the second signal-quality metric;
• and determine whether the mobile device is within a proximity region defined with respect to the target location based on a comparison of the ratio with a ratio constant which is a ratio of a first distance between each point of a set of points of the proximity region surrounding the target location and the first receiver, and a second distance between the each point of the set of points and the second receiver.