Conventionally, terminal apparatuses such as mobile telephones have performed a radio communication with a base station to receive and transmit information. If the terminal apparatus moves to a location that radio waves from the base station do not reach, communication of the terminal apparatus is cut off and the communication process is interrupted. Disclosed as a technique to address such a case of cutoff of communication between a terminal apparatus and a base station is a technique using ad-hoc communication to allow, for example, another terminal apparatus different from the terminal apparatus to relay communication to the base station (see, for example, Japanese Laid-Open Patent Publication Nos. 2007-89021 and 2004-27450).
Recently, various functions are continually added to terminal apparatuses and consequently, the load placed on the terminal apparatuses is increasing. Disclosed as a load distribution technique is a technique in which a single terminal apparatus has plural radio communication units and performs communication using an optimal radio communication unit. Disclosed as a load distribution technique at a based station is a technique in which a terminal apparatus receives congestion information from plural base stations and selects an optimal base station to perform communication (see, for example, Japanese Laid-Open Patent Publication Nos. 2005-295087 and 2002-159038).
In the prior art described above, however, the techniques of Japanese Laid-Open Patent Publication Nos. 2007-89021 and 2004-27450 have a problem in that a low-speed communication channel may be selected although the communication can continue despite communication between a terminal apparatus and a base station being cut off. The technique of Japanese Laid-Open Patent Publication No. 2005-295087 has a problem in that a specific terminal apparatus may remain subjected to an excessive load.
USPTO Backgrounds
USPTO Backgrounds