Patent ID: 8452280
Filing Date: 2013-05-28
Classification: H04W,Y02D

Abstract:
1. A mobile radio terminal comprising: a first storing section which stores identification information of a plurality of radio base stations; a second storing section which stores identification information of radio base stations with which the mobile radio terminal has carried out communications, the identification information stored by the second storing section being included in the identification information stored by the first storing section; a receiving section which is adapted to receive a radio signal transmitted from a radio base station; a detecting section which detects, based on a reception result of the receiving section, whether the mobile radio terminal has failed to carry out communications with a radio base station; a searching section which, when the detection section detects that the mobile radio terminal has failed to carry out communications with a radio base station, carries out a search for a radio base station capable of carrying out communications with the mobile radio terminal, wherein the search comprises: (i) controlling the receiving section based on the identification information stored in the first storing section to conduct a first search for a radio base station capable of carrying out communications with the mobile radio terminal each time that a first search cycle elapses, and (ii) controlling the receiving section based on the identification information stored in the second storing section to conduct a second search for a radio base station capable of carrying out communications with the mobile radio terminal from among the radio base stations with which the mobile radio terminal has carried out communications, each time that a second search cycle elapses; and a search cycle varying section which gradually increases, in response to the detection section detecting that the mobile radio terminal has moved outside a service area, a length of the first search cycle as a length of the search carried out by the searching section increases, and which independently and gradually increases a length of the second search cycle as the length of the search carried out by the searching section increases, wherein the search cycle varying section sets the second search cycle to be shorter than the first search cycle so that the second search is conducted a plurality of times within the first search cycle.