US Patent 9413453 Wireless communication method and wireless communication system

In a wireless communication system based on a time division multiple access method such as cordless telephone systems including a door camera, voice communication is performed in a bi-directional communication by using a paired time slots, and image communication is performed in a uni-directional communication by using both of paired time slots. One of the paired time slots may be used for transmitting a control signal such as an image data resend control signal.