USAGE ADVISABILITY CONTROL SYSTEM OF PORTABLE TELEPHONE, PORTABLE TELEPHONE SET, INTERROGATOR, RESPONDER AND USAGE ADVISABILITY CONTROL METHOD OF PORTABLE TELEPHONE

摘要

PROBLEM TO BE SOLVED: To overcome the problem wherein usage advisability of a portable telephone set 101 cannot be controlled surely, since a signal from simple base station equipment 100 is propagated to a region of a certain wide area which exceeds an area in the vicinity of an entrance, when a propagation area of radio wave of specified small power is not adjusted precisely, possibility exists that a power-on signal 109 is received erroneously in the step that the portable telephone set 101, in which power of a radio communication part which communicates with public base station equipment 102 is tuned off enters a building 105, and distinction of entering and exiting persons is difficult. SOLUTION: This system controls usage advisability of a portable telephone set which enters or leaves a specified communication restricted region. The system is provided with an interrogating means which is arranged at an entrance or an exit in the communication restricted region and outputs a signal for identifying itself by using a magnetic field as communication medium, and a responding means which is arranged in the portable telephone set and turns a power source of the portable telephone set on or off by receiving a signal from the interrogating means.