To maintain communication even if a radio communication terminal is out of the communication range.

In the situation where radio communication terminals MN1, MN2 perform communication via a base station AP1 within a communication range 50 of the base station AP1, the radio communication terminal MN1 measures a receiving radio wave intensity RRSI from the base station AP1 to detect trial of moving outside the communication range of the base station AP1, and the radio communication terminal MN1 starts handover operation. Ordinarily, another peripheral communicable base station is found out to perform handover but if other base stations are not present at all, a relief signal requesting relay of data to the base station AP1 is transmitted to the radio communication terminal MN2 with which the own terminal MN1 communicates and which is located within the communication area 50 of the base station AP1. When the radio communication terminal MN2 receives this relief signal, the radio communication terminal MN2 serves as a repeater station between the radio communication terminal MN1 and the base station AP1.