Mobile host, paging agent, packet communication system and movement detection method

摘要

A mobile host 2 as an embodiment of the invention comprises a data link layer connection establishment notification unit 202 for notifying the network layer that a connection to a link layer in the data link has been established during a Dormant state; a router information requesting unit 203 for transmitting, in response to the notification by the data link layer connection establishment notification unit 202, a router request signal which requests for transmission of router advertisement information to the access router 3 existing on the access link 4 to which the mobile host is connected; and a network layer movement detection unit 204 for detecting a default router, based on the router advertisement information returned from the access router 3 in response to the router request signal.