A system and method thereby each of a plurality of agent servers keeps and
manages history of movement. Each of the agent servers temporarily stores
requests for updates of location information of a mobile agent associated
to accumulated number of movement of the mobile agent and periodically
sends it to a registration server so that no congestion will occur in
accessing the registration server. The registration server renews
location information of a mobile server only with the request for update
of a higher accumulated number of movements so as not to overwrite newer
information with older information.