A portable memory module, which comprises an interface allowing the module to be connected to and disconnected from an electronic device by a user of the module such that the electronic device is in close physical proximity to the module when connected thereto; memory storing an identifier of the module; an emitter; and a processing entity configured to encode the identifier of the module into a signal that is transmitted via the emitter as a wireless beacon. The memory contains information that allows the module to be identified by an entity connected to the electronic device. The wireless beacon is configured to enable a location of the module to be determined by a detection sub-system. When the module is connected to the electronic device and the identity of the module is transmitted to a network entity via the electronic device, the location of the module can be used by the network entity to establish the location of the electronic device.