Separate buffering of handover related data packets and application related data packets in handover

Disclosed is a method of performing a media independent handover (MIH) of a mobile device from a first wireless network to a second wireless network, the mobile device being connected, via a tunnel, to a Server of a Mobile IP system, and to an information server coupled to the first and second wireless networks, wherein the information server is arranged to provide handover related messages to the mobile device to assist the mobile device in performing a handover from the first wireless network to the second wireless network, comprising the steps of : determining that a handover is imminent or in progress and buffering data packets transmitted from the mobile device, wherein data packets containing handover related messages are stored in a separate buffer 320 and are transmitted in preference to data packets containing application data, 340 The buffer sizes (320, 340) may be dynamically varied and the relative priority of packets containing handover data and packets containing application data may be dynamically altered.