Communication system, communication apparatus, and communication method

1 . A communication system comprising:

a first communication device, including one or more processors, configured to transmit a startup instruction signal; and

a second communication device, including one or more processors, configured to restart supply of power that has been stopped in a sleep state when receiving the startup instruction signal from the first communication device, and comprises a signal processing unit that includes transmission data in a start completion signal when generating the start completion signal that is a response signal to the startup instruction signal, wherein:

the second communication device includes a power supply control unit configured to control power supply;

the first communication device is configured to transmit the startup instruction signal including power supply interval information indicating an interval of power supply performed during the sleep state by the power supply control unit;

the second communication device further includes a reception unit configured to receive a signal transmitted by the first communication device;

the signal processing unit of the second communication device includes a lower signal processing unit configured to determine whether or not the signal received by the reception unit is the startup instruction signal;

the power supply control unit supplies power to the reception unit and the lower signal processing unit during the sleep state according to an interval indicated by the power supply interval information; and

the first communication device is configured to transmit the startup instruction signal according to the interval indicated by the power supply interval information.

2 . The communication system according to claim 1 , wherein:

the second communication device includes a radio communication unit configured to receive data by radio,

and a storage unit configured to store the data received by the radio communication unit as the transmission data;

and the power supply control unit is configured to supply power to the radio communication unit and the storage unit, during the sleep state according to the interval indicated by the power supply interval information.

3 . The communication system according to claim 1 , wherein:

the second communication device includes the radio communication unit that receives data by radio, the storage unit that stores the data received by the radio communication unit as the transmission data, and the power supply control unit that controls power supply; and

the power supply control unit is configured to supply power to the radio communication unit and the storage unit, during the sleep state according to an interval indicated by a period of a clock signal supplied from the outside.

4 . The communication system according to claim 1 , wherein:

the second communication device includes the reception unit that receives a signal transmitted by the first communication device, a transmission unit configured to transmit a signal to the first communication device, and the power supply control unit that controls power supply;

the signal processing unit of the second communication device includes the lower signal processing unit that causes the transmission unit to transmit the start completion signal and to output a startup instruction reception notification signal when the signal received by the reception unit is the startup instruction signal;

and an upper signal processing unit that causes the lower signal processing unit to generate the start completion signal including the transmission data when the supply of power is resumed,

and the power supply control unit is configured to supply power to the reception unit and the lower signal processing unit during the sleep state, stops power supply to the transmission unit and the upper signal processing unit during the sleep state, and when the lower signal processing unit outputs the startup instruction reception notification signal, restarts supply of the power that has been stopped in the sleep state to the transmission unit and the upper signal processing unit.

5 . A communication device, including one or more processors, configured to restart supply of power that has been stopped in a sleep state upon reception of a startup instruction signal,

wherein the communication device includes a signal processing unit that includes transmission data in a start completion signal, when generating the start completion signal that is a response signal to the startup instruction signal;

wherein the communication device further includes a power supply control unit configured to control power supply;

wherein the startup instruction signal includes power supply interval information indicating an interval of power supply performed during the sleep state by the power supply control unit;

wherein the communication device further includes a reception unit configured to receive a signal transmitted by an external communication device;

wherein the signal processing unit includes a lower signal processing unit configured to determine whether or not the signal received by the reception unit is the startup instruction signal;

wherein the power supply control unit is configured to supply power to the reception unit and the lower signal processing unit during the sleep state according to an interval indicated by the power supply interval information; and

wherein the external communication device is configured to transmit the startup instruction signal according to the interval indicated by the power supply interval information.

6 . A communication method, comprising:

transmitting, by a first communication device, a startup instruction signal; restarting, by a second communication device, supply of power stopped in a sleep state when receiving the startup instruction signal from the first communication device, and including transmission data in the start completion signal, when generating a start completion signal that is a response signal to the startup instruction signal, wherein the startup instruction signal includes power supply interval information indicating an interval of power supply performed during the sleep state by the second communication device;

controlling power supply by the second communication device;

receiving, by the second communication device, a signal transmitted by the first communication device;

determining, by the second communication device, whether or not the signal received by the second communication device is the startup instruction signal;

supplying, by the second communication device, power to a reception unit and a lower signal processing unit during the sleep state according to an interval indicated by the power supply interval information.