Patent ID: 8224351

Claim:
A computer-implemented method for identifying proximity of a mobile computing device to another mobile computing device, the method comprising: determining, by a computing system, that a set of mobile computing devices are geographically proximate to a first mobile computing device based at least in part on identifying that each of the mobile computing devices in the set received a first type of signal from an emitting device for which the first mobile computing device also received the first type of signal, wherein: the first type of signal is an electromagnetic signal, determining that the set of mobile computing devices are geographically proximate to the first mobile computing device includes identifying, for each particular mobile computing device in the set, that a proportion of a first quantity of emitting devices to a second quantity of emitting devices exceeds a threshold proportion value, the first quantity of emitting devices represents a quantity of emitting devices from which both a particular mobile computing device from the set and the first mobile computing device received signals, and the second quantity of emitting devices represents (i) a quantity of emitting devices from which the particular mobile computing device received signals, (ii) a quantity of emitting devices from which the first mobile computing device received signals, or (iii) a quantity of emitting devices from which the particular mobile computing device received signals together with a quantity of emitting devices from which the first mobile computing device received signals; and determining, by the computing system, a subset of the mobile computing devices in the set that share a physical space with the first mobile computing device based at least in part on identifying that each of the mobile computing devices in the subset emitted a second type of signal that was detected by the first mobile computing device, or detected the second type of signal that was emitted by the first mobile computing device.