Patent ID: 8315206

Claim:
A proxy mobile IP system comprising: a mobile terminal including a time management/notification unit; said time management/notification unit alerting a time information, managed by the mobile terminal itself, to an access gateway at the time of access authentication in proxy mobile IP (Internet Protocol) communication; said access gateway; said access gateway including a time information acquisition/management unit alerting the time information, received from said mobile terminal, to a mobility anchor, at the time of performing proxy mobile IP registration in said proxy mobile IP communication, as said time information received from said mobile terminal is carried on a registration notification message; and said mobility anchor; said mobility anchor including a time information acquisition/management unit alerting said registration notification message including said time information to a proxy mobile IP registration unit responsible for performing proxy mobile IP registration, wherein if said mobility anchor has received a registration notification message of the time information older than the time information embedded within the registration message and saved in the mobility anchor, said mobility anchor saves the time information of the registration message as the current time information and alerts an error to said access gateway to acquire the time information of said mobile terminal again.