Device for transmitting and receiving
A device for transmitting and receiving is disclosed that includes: a) an antenna, b) a transmitting/receiving unit for transmitting and receiving data according to a communications standard, which has a transmitting unit, connected to the antenna, for transmitting first data frames to a second transmitting/receiving device and a receiving unit, connected to the antenna, for receiving second data frames from the second transmitting/receiving device, and c) a control unit, connected to the transmitting/receiving unit for controlling the transmitting/receiving unit, whereby the control unit is designed (c 1 ) to instruct the transmitting/receiving unit to transmit a first data frame and (c 2 ) to receive the second data frame from the transmitting/receiving unit. According to the invention, the transmitting/receiving unit has a controller, which is connected to the receiving unit and the control unit and is designed d) to evaluate a second data frame, received by the receiving unit within a predefined time interval after the transmission of the first data frame, and to determine whether the second data frame contains an acknowledgment message for the successful receipt of the first data frame by the second transmitting/receiving device, and e) not to relay the second data frame to the control unit, if it is determined that it contains the acknowledgment message.
1. A device for transmitting and receiving, the device comprising:
an antenna;
a transmitting/receiving unit for transmitting and receiving data according to a communication standard, the transmitting/receiving unit including a transmission unit connected to the antenna for transmitting first data frames to a second transmitting/receiving device, the transmitting/receiving unit including a receiving unit connected to the antenna for receiving second data frames from the second transmitting/receiving device; and
a control unit connected to the transmitting/receiving unit for controlling the transmitting/receiving unit, the control unit being configured to instruct the transmitting/receiving unit to transmit a first data frame and to receive a second data frame from the transmitting/receiving unit;
wherein the transmitting/receiving unit has a controller, which is connected to the receiving unit and the control unit, and evaluates a second data frame received by the receiving unit within a predefined time interval after transmission of the first data frame and determines whether the second data frame contains an acknowledgment message for a successful receipt of the first data frame by the second transmitting/receiving device and to relay the second data frame to the control unit only if it is determined that it does not contain the acknowledgment message in order to reduce power requirements of said control unit when said second data frame contains an acknowledgement message.
2. The device according to claim 1 , wherein the control unit has at least two operating modes with a different high power consumption and shifts to a power-saving mode with a low power consumption when the control unit instructs the transmitting/receiving unit to transmit the first data frame.
3. The device according to claim 2 , wherein the control unit exits the power-saving mode when it receives an interrupt from the controller.
4. The device according to claim 1 , wherein the controller, before the transmission of the first data frame, instructs the receiving unit to check whether the transmission channel specified for the transmission of the first data frame is busy and instructs the transmission unit to transmit the first data frame only when the check has shown that the specified transmission channel is not busy.
5. The device according to claim 1 , wherein the controller informs the control unit, via an interrupt, if no second data frame is received within a predefined time interval or that the second data frame does not contain the acknowledgment message.
6. The device according to claim 1 , wherein the controller is connected to the transmission unit and includes a memory, wherein the controller stores the first data frame in the memory, and without instruction by the control unit prompts the transmission unit to retransmit the first data frame to the second transmitting/receiving device if no second data frame is received within the predefined time interval or that the second data frame does not contain the acknowledgment message.
7. The device according to claim 6 , wherein the controller informs the control unit, via an interrupt, only when, after a predefined number of prompts, not given by the control unit to retransmit the first data frame to the second transmitting/receiving device, no second data frame, which contains the acknowledgment message, was received within the predefined time after the specific retransmission.
8. The device according to claim 1 , wherein the controller evaluates the first data frame and determines whether, in the case of a successful receipt by the second transmitting/receiving device, the acknowledgment message is expected, wherein, if the acknowledgment message is expected, the controller evaluate the second data frame to determine whether it contains the acknowledgment message, and wherein the controller does not relay the second data frame to the control unit if the acknowledgment message is expected and if it is determined that the second data frame contains the acknowledgment message.
9. The device according to claim 8 , wherein the controller informs the control unit, via an interrupt, if the acknowledgment message is expected and if no second data frame is received within the predefined time interval or if it is determined that the second data frame does not contain the acknowledgment message.
10. The device according to claim 8 , wherein the controller is connected to the transmitting unit and has a memory, wherein the controller stores the first data frame in the memory and, without instruction by the control unit, prompts the transmission unit to retransmit the first data frame to the second transmitting/receiving device if the acknowledgment message is expected, and if no second data frame is received within a predefined time interval or if it is determined that the second data frame does not contain the acknowledgment message.
11. The device according to claim 10 , wherein the controller informs the control unit, via an interrupt, only when the acknowledgment message is expected and when, after a predefined number of prompts not given by the control unit, to retransmit the first data frame to the second transmitting/receiving device when no second data frame, which contains the acknowledgment message, was received within the predefined time after the specific retransmission.
12. The device according to claim 7 , wherein the predefined number of prompts to retransmit the first data frame to the second transmitting/receiving device has a value in a range of one to five.
13. The device according to claim 6 , wherein the controller, before the retransmission of the first data frame, instructs the receiving unit to check whether the transmission channel specified for the retransmission of the first data frame is busy, and instructs the transmission unit to retransmit the first data frame only when the check has shown that the specified transmission channel is not busy.
14. The device according to claim 4 , wherein, if the check has shown that the specified transmission channel is busy, the controller instructs the receiving unit at a later time to check whether the specified transmission channel is busy, wherein the controller instructs the transmission unit to transmit the first data frame only when the repeated check has shown that the specified transmission channel is not busy, and wherein the controller informs the control unit, via an interrupt, only when a predefined number of checks each have shown that the specified transmission channel is busy.
15. The device according to claim 14 , wherein the predefined number of checks has a value in the range of three to seven.
16. The device according to claim 1 , wherein the predefined time interval has a duration between 150 μs and 500 μs or between 300 μs and 400 μs.
17. The device according to claim 1 , wherein the transmitting/receiving unit performs the functionalities of a physical layer and a portion first functionalities of a MAC layer of the communication standard and wherein the control unit performs only the remaining second functionalities of the MAC layer and optionally the functionalities of higher layers.
18. The device according to claim 1 , wherein the transmitting/receiving unit is an ASIC or ASSP and/or the control unit is a microcontroller.
19. The device according to claim 1 , wherein the transmitting/receiving unit and the control unit are a single integrated circuit.
20. The device according to claim 1 , wherein the device transmits and receives according to IEEE Standard 802.15.4.