Connection server to configure the security level according to the distance between devices, a client device, a communication system, the server control integrated circuit, the client control integrated circuit, server program, the client program to the client device to the server device communication system connection method and connection method,

摘要

Server apparatus capable without the need for high-performance terminal implementations, to vary the strength of security depending on the distance between devices, and provides a client device. Server device for providing a service to the client device (200) to (100), and a (120), service providing unit (110), the optical signal transmission unit information management unit (130). Information management unit (110) to manage and stored in association with the importance and connection information of a plurality of different types of severity needed to connect to the service. First by modulating the optical signal taken smaller change in the intensity of light as the connection information stored in association with a higher importance level connection information of a plurality of kinds of stored optical signal transmitter (120) to be transmitted by the communication function. If the connection request with the connection information of a predetermined type by the communication function of the second is made from (200), using the connection information, providing service to (200) the client device The client device (130) service providing unit to.