Abstract: A method of identifying mobile devices (1,1?) capable of communicating (C) with each other comprises the steps of deriving, for each mobile device, movement information from movements (M) made by the mobile device within a respective time period, and communicating the movement information. The method comprises the further steps of comparing the movement information of the mobile device (1) with the movement information of at least one other mobile device (T), and identifying mobile devices having matching movement information. The step of deriving movement information is carried out using sensors mounted in the mobile device, such as acceleration sensors and/or optical sensors. The step of comparing the movement information may be carried in a mobile device (1) or in a central unit.

Abstract: A method of identifying mobile devices (1, 1?) capable of communicating (C) with each other comprises the steps of deriving, for each mobile device, movement information from movements (M) made by the mobile device within a respective time period, and communicating the movement information. The method comprises the further steps of comparing the movement information of the mobile device (1) with the movement information of at least one other mobile device (T), and identifying mobile devices having matching movement information. The step of deriving movement information is carried out using sensors mounted in the mobile device, such as acceleration sensors and/or optical sensors. The step of comparing the movement information may be carried in a mobile device (1) or in a central unit.