A method for selecting a data communication interface to be used by a mobile device having at least a wireless local area network interface connected to a wireless local area data network and a cellular network interface connected to a cellular data network, the method comprising a wireless access point device including a wireless local area network interface, a cellular network interface, and a wide area network interface, wherein the wireless access point device carries out the steps of: inspecting and routing incoming packets to and from the interfaces (9, 59, 53); determining an identifier associated with a local wireless network adaptor of the mobile device; monitoring control messages passing between the mobile device and a network core control function in the cellular data network to determine an identifier associated with the mobile device connected to the cellular data network; associating the determined and retrieved identifiers with said mobile device including storing a mapping containing: the identifier associated with the wireless network adapter of the mobile device; and the identifier associated with the cellular mobile device connected to the cellular data network; determining device presence information regarding the presence of the mobile device on the cellular data network in accordance with the monitored control information messages; determining first network operation parameters of the wireless local area data network; determining second network operation parameters of the cellular network interface of the mobile device; selecting one of the wireless local area network interface and the cellular network interface in accordance with the determined first and second network operation parameters; and causing the mobile device to use the selected network interface for any existing and new data sessions and redirecting the data sessions based on the identifiers of the mobile device, wherein in response to the processing of the wireless access point, the mobile device is operable to use the selected network interface and disconnect from the non-selected network interface. inspecting and routing incoming packets to and from the interfaces (9, 59, 53); determining an identifier associated with a local wireless network adaptor of the mobile device; monitoring control messages passing between the mobile device and a network core control function in the cellular data network to determine an identifier associated with the mobile device connected to the cellular data network; associating the determined and retrieved identifiers with said mobile device including storing a mapping containing: the identifier associated with the wireless network adapter of the mobile device; and the identifier associated with the cellular mobile device connected to the cellular data network; the identifier associated with the wireless network adapter of the mobile device; and the identifier associated with the cellular mobile device connected to the cellular data network; determining device presence information regarding the presence of the mobile device on the cellular data network in accordance with the monitored control information messages; determining first network operation parameters of the wireless local area data network; determining second network operation parameters of the cellular network interface of the mobile device; selecting one of the wireless local area network interface and the cellular network interface in accordance with the determined first and second network operation parameters; and causing the mobile device to use the selected network interface for any existing and new data sessions and redirecting the data sessions based on the identifiers of the mobile device, wherein in response to the processing of the wireless access point, the mobile device is operable to use the selected network interface and disconnect from the non-selected network interface.