Abstract: According to one aspect, a device identification system is provided for automatically identifying mobile devices and providing data which may be used to optimise content or services to be provided to the mobile device. According to some embodiments, a system is provided for implementing a method for device identification wherein a mobile content server requests device identification from a local device identifying station, which attempts to find matching identification data in a locally stored repository. According to one embodiment, in the event that matching data is found, the local station transmits matching identification data to the content server; in the event that matching data is not found, the local station transmits the received data to a central identifying station, receives device identifying data from the central identifying station and transmits the received device identification data to the server.