To provide a communication system and method, a storage medium, imaging device and its method and medium for realizing power economy for the imaging device and the communication system, when image data are transferred between an imaging device and the communication system.

In the communication system 300, an inter-system communication, such as communication, based on Bluetooth specifications between the communication system 300 and the imaging device 100 is started periodically, when the operation mode set by a user is in a full-power mode. When the operation mode set by the user is in a power economy mode, however, the communication between the systems is stopped for power economy of the communication system 300.