A transmitting device, a receiving device, a wireless communication system and a method for controlling the wireless communication system are used for creating a secure wireless communication network of a limited area. The transmitting device comprises: one or more transmitters configured to transmit wireless signals, and create the limited area by a coverage scope of the wireless signals; a cryptography key generating unit configured to generate a cryptography key for the wireless signals; a cryptography key encoding unit configured to encode the cryptography key to a cryptography key frame; and a cryptography key scheduling unit configured to schedule the cryptography key frame so as to control the transmitter to transmit the wireless signals including the cryptography key frame.