Patent attributes
Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for computing distance between devices. In one aspect, a method includes the actions of determining an approximate distance between a merchant computer and a customer device based on a strength of a wireless signal associated with data transmitted and received between the merchant device and customer device. The actions further include validating the approximate distance based on signals from a plurality of motion sensors of the customer device to generate a validated distance. The actions further include generating a list with the one or more customers ranked in the list based on the validated distance. The actions further include presenting, on the merchant device, the list of the one or more customers.