Patent ID: 8422462

Claim:
A mobile communication apparatus that has a plurality of types of radio communication interfaces and receives, from a mobile communication network, a vertical handover execution request that requests to switch a radio communication interface in use to another radio communication interface, to execute vertical handover, the mobile communication apparatus comprising: a measurement processing section that measures connection quality of each of the plurality of types of radio communication interfaces; a handover execution prediction section that predicts whether or not to execute the vertical handover, based on the connection quality; a transmission control protocol control section that sets a window size in use to a smaller window size than the window size in use when the handover execution prediction section predicts that the vertical handover is executed; a window control timer that counts time; and a window control timer management section that, when the handover execution prediction section predicts that the vertical handover is executed, determines a predicted handover execution period during which data is transmitted and received in the smaller window size and manages the window control timer to count the predicted handover execution period, wherein, when the window control timer is stopped according to reception of the vertical handover execution request or the predicted handover execution period has expired, the transmission control protocol control section performs transmission control protocol window setting for optimizing the window size.