| 摘要 |
A radio terminal includes: a communication judgment unit (131) which judges whether a direct communication with a radio base station can be continued; a message processing unit (132) which transmits a search instruction asking whether a direct communication with the radio base station is possible to a lower-node radio terminal in a tree-structure network when it is judged that the direct communication with the radio base station cannot be continued; and a master management unit (133) which registers the lower-node radio terminal as an upper-node radio terminal in the tree-structure network upon reception of a response message indicating that the direct communication with the radio base station is possible from the lower-node radio terminal. |
