Patent attributes
A communication device includes an interface connector for connecting to a computing circuit to receive a media data and an external power supply, a transmission circuit, wherein the circuit transmits the media data to a network, a battery power supply, a controller circuit powered by the battery power supply, a sensor, communicatively coupled to the controller circuit, for detecting a movement of the communication device, a switch circuit for switchably connecting the battery power supply to the transmission circuit responsive to a first switch control signal, and a test circuit, communicatively coupled to the controller circuit, for generating the first switch control signal based on an external power control signal indicating whether the interface connector is connected to the computing circuit and a motion detection signal indicating whether the sensor detects the movement of the communication device.