Positioning system for determining the location of a device

A wireless device comprising: a wireless interface for communicating with a network of reference nodes, and a location module configured to obtain a measurement of a respective signal communicated between the wireless interface and each of a plurality of said reference nodes. The location module is also supplied with a respective set of transformed coordinates for each of said plurality of reference nodes, transformed relative to their actual physical coordinates. Using said signal measurements and the transformed coordinates of said plurality of reference nodes, the wireless device then submits information indicative of a transformed location of the wireless device to an interpretation function. Based on the interpretation function, the wireless device is thereby able to access functionality relating to the physical location of the mobile terminal.