Method and apparatus for updating software in radio terminal device

A radio terminal device comprising:

• a radio communication unit capable of transmitting and receiving digital signals;
• a main memory storing control-software presently involved in operations including a radio communication control of said radio terminal device and update-software for updating said control-software presently involved;
• a buffer memory;
• and
• a processing unit that operates in accordance with said control-software in said main memory,
• wherein said processing unit causing update-used software downloaded through a radio communication channel under a control of said control-software presently involved to be temporarily stored in said buffer memory and updates, under a control of said update-software, parts of said control-software presently involved with said update-used software, so that the processing unit can operate in accordance with updated control-software.

A software-supply device comprising:

• a communication interface unit capable of transmitting and receiving digital signals connected to network;
• a memory storing every version of control-software involved in operations of a radio terminal device and version information on said control-software;
• and
• a communication control unit updating and managing contents of said memory, said communication control unit being capable of communication with any radio terminal device through a communication interface unit.