Radio communication system with high security level, and communication unit and portable terminal used therefor

A first communication unit used with a radio communication system including a plurality of first communication units, a second communication unit, and a portable terminal establishing radio communication with each of said first communication units, said portable terminal receiving said identification information from said first communication unit and transmitting said identification information to said second communication unit, said second communication unit receiving said identification information from said portable terminal, searching authentication information registered corresponding to identification information received from said portable terminal, from identification information and authentication information registered corresponding to each of said first communication units, and transmitting searched authentication information to said portable terminal, said portable terminal receiving said searched authentication information from said second communication unit, and transmitting information requesting connection of said portable terminal with said first communication unit to said first communication unit;

• wherein
• said first communication unit includes
• storage means for storing identification information for identifying the unit itself and authentication information corresponding to said identification information,
• transmission means connected to said storage means, for transmitting said identification information to said portable terminal,
• reception means for receiving information requesting connection from said portable terminal, and
• determination means connected to said reception means and said storage means, for determining whether or not connection of said portable terminal to said first communication unit is permitted, based on said stored authentication information.

A second communication unit used with a radio communication system including a plurality of first communication units, the second communication unit, and a portable terminal establishing radio communication with each of said first communication units, said first communication unit storing identification information for identifying the unit itself and authentication information corresponding to said identification information, and transmitting said identification information to said portable terminal, said portable terminal transmitting said identification information received from said first communication unit to said second communication unit, receiving searched authentication information from said second communication unit, and transmitting information requesting connection of said portable terminal with said first communication unit to said first communication unit, and said first communication unit receiving information requesting connection from said portable terminal to determine whether or not connection of said portable terminal to said first communication unit is permitted based on said searched authentication information and said stored authentication information;

• wherein
• said second communication unit includes
• reception means for receiving said identification information from said portable terminal,
• first registration means for registering the identification information and the authentication information corresponding to each of said first communication units,
• search means connected to said reception means and said first registration means, for searching the registered authentication information based on the identification information received from said portable terminal, and
• transmission means connected to said search means, for transmitting searched authentication information to said portable terminal.

A portable terminal used with a radio communication system including a plurality of first communication units, a second communication unit, and the portable terminal establishing radio communication with each of said first communication units, said first communication unit storing identification information for identifying the unit itself and authentication information corresponding to said identification information, and transmitting said identification information to said portable terminal, said second communication unit receiving said identification information from said portable terminal, registering identification information and authentication information corresponding to each of said first communication units, searching registered authentication information based on the identification information received from said portable terminal, and transmitting searched authentication information to said portable terminal, said first communication unit receiving information requesting connection from said portable terminal, and determining whether or not connection of said portable terminal to said first communication unit is permitted based on said stored authentication information;

• wherein
• said portable terminal includes
• first reception means for receiving said identification information from said first communication unit,
• first transmission means for transmitting said identification information to said second communication unit,
• second reception means for receiving said searched authentication information from said second communication unit, and
• second transmission means for transmitting information requesting connection of said portable terminal with said first communication unit to said first communication unit.