Communication device and communication system
According to an embodiment, a communication device includes a wake-up signal reception unit configured to receive a wake-up signal to request a change of a state from a second state to a first state, the second state requiring less power consumption than the first state; and a state control unit configured to change the state from the second state to the first state and inform a control unit of the change of the state when the wake-up signal is received, the control unit being configured to process a frame received during the first state.
1. A communication device comprising:
a wake-up signal reception unit configured to receive a wake-up signal to request a change of a state from a second state to a first state, the second state requiring less power consumption than the first state;
a state control unit configured to initiate a change of the state from the second state to the first state and inform a control unit of the change of the state in response to reception of the wake-up signal, the control unit being configured to process a frame received during the first state; and
a response signal transmission unit configured to transmit, in response to reception of the wake-up signal, a response signal containing communication device identification information that identifies the communication device and wake-up identification information that is varied in response to the control unit being re-started.
2. The communication device according to claim 1 , wherein
the control unit is a central processing unit, and
the communication device further comprises a direct memory access (DMA) control unit configured to transfer the frame by means of direct memory access to a memory accessible by the central processing unit.
3. The communication device according to claim 1 , wherein
the state control unit is further configured to change the state from the second state to the first state in response to the state control unit being informed by the control unit of a frame transmission event indicative of a start of a transmission of a frame during the second state, and
the communication device further comprises a wake-up signal transmission unit configured to transmit a wake-up signal in response to a determination that the state has changed from the second state to the first state.
4. The communication device according to claim 1 , wherein the response signal is a first response signal, and the communication device further comprises a response signal reception unit configured to receive a second response signal, wherein
in response to a determination that at least one of first communication device identification information or first wake-up identification information contained in a previously received response signal is different from at least one of second communication device identification information or second wake-up identification information contained in the second response signal received subsequent to the previously received response signal, the response signal reception unit determines that a failure has occurred.
5. The communication device according to claim 4 , wherein, in response to a determination that the failure has occurred, the state control unit informs the control unit of occurrence of the failure.
6. The communication device according to claim 4 , wherein the response signal reception unit is further configured to determine a parameter using a bit pattern contained in the second response signal.
7. The communication device according to claim 1 , further comprising a frame reception unit configured to receive a frame and determine a parameter using a bit pattern contained in the frame.
8. The communication device according to claim 1 , wherein the wake-up signal contains information regarding a communication scheme.
9. A communication system comprising:
a transmission node and a reception node, wherein
the transmission node comprises
a wake-up signal transmission unit configured to transmit a wake-up signal to request a change of a state from a second state to a first state, the second state requiring less power consumption than the first state, and the reception node comprises
a wake-up signal reception unit configured to receive the wake-up signal;
a state control unit configured to initiate a change of the state from the second state to the first state and inform a control unit of the change of the state in response to reception of the wake-up signal, wherein the control unit is configured to process a frame received during the first state; and
a response signal transmission unit configured to transmit, in response to reception of the wake-up signal, a response signal containing communication device identification information that identifies the communication device and wake-up identification information that varies in response to the control unit being re-started.