Fast detection/mitigation and recovery for severe EMI conditions in automotive area networks
View Patent ↗A vehicle communication network device includes a transceiver configured to communicatively couple with a remote transceiver of another vehicle communication network device via a wired media and processing circuitry coupled to the transceiver. The device detects interference on the wired media that exceeds an interference threshold level. Upon the detection, the device enters a quiet mode during which no data is transmitted on the wired media. After exiting the quiet mode, the device enters an idle mode during which known data is transmitted on the wired media and during which the device receives known data from the remote transceiver. The device retrains its transceiver based upon the known data and after retraining the transceiver, exchanges data with the remote transceiver. The device may also buffer data for transmission, upon the detection, determine buffered data that was likely corrupted by the interference, and after retraining, retransmit the determined buffered data.
1. A vehicle communication network device comprising:
a transceiver configured to communicatively couple with a remote transceiver of another vehicle communication network device via a wired media; and
processing circuitry coupled to the transceiver, wherein the processing circuitry and transceiver are configured to:
detect interference on the wired media that exceeds an interference threshold level by determining that a number of soft decisions that fall in a sliding soft decision error window exceeds an error threshold;
upon the detection, enter a quiet mode during which no data is transmitted on the wired media;
after exiting the quiet mode, enter an idle mode during which known data is transmitted on the wired media;
receive known data from the remote transceiver;
retrain the transceiver based upon the known data; and
after retraining the transceiver, exchange data with the remote transceiver.
2. The vehicle communication network device of claim 1 , wherein the processing circuitry and transceiver are further configured to:
buffer data for transmission;
upon the detection, determine buffered data that was likely corrupted by the interference; and
after retraining, retransmit the determined buffered data.
3. The vehicle communication network device of claim 1 , wherein the wired media comprises an unshielded twisted pair wire.
4. The vehicle communication network device of claim 3 , wherein the transceiver further provides power to the remote transceiver via the unshielded twisted pair wire.
5. The vehicle communication network device of claim 1 , wherein the transceiver supports wired local area network communications.
6. The vehicle communication network device of claim 1 , wherein in detecting that the interference on the wired media exceeds the interference threshold level, the processing circuitry and transceiver are further configured to detect that a signal quality available on the wired media is less than at least one of a Signal to Interference Ratio (SNR) threshold level, a Bit Error Rate (BER) threshold level, or a Block Error Rate (BLER) threshold level.
7. The vehicle communication network device of claim 1 :
further comprising a Decision Feedback Equalizer (DFE) configured to equalize incoming data; and
wherein retraining the transceiver using the known data comprises retraining the DFE using the known data.
8. A method of operating a vehicle communication network device comprising:
communicating with a remote transceiver of another vehicle communication network device via a transceiver and wired media;
detecting interference on the wired media that exceeds an interference threshold level by determining that a number of soft decisions that fall into a sliding soft decision error window exceeds an error threshold;
upon the detection, entering a quiet mode during which no data is transmitted on the wired media;
after exiting the quiet mode, entering an idle mode during which known data is transmitted on the wired media;
receiving known data from the remote transceiver;
retraining the transceiver based upon the known data; and
after retraining the transceiver, exchanging data with the remote transceiver.
9. The method of claim 8 , further comprising:
buffering data for transmission;
upon the detection, determining buffered data that was likely corrupted by the interference; and
after retraining, retransmitting the determined buffered data.
10. The method of claim 8 , wherein the wired media comprises an unshielded twisted pair wire.
11. The method of claim 10 , further comprising providing power to the remote transceiver via the unshielded twisted pair wire.
12. The method of claim 8 , further comprising the transceiver supporting wired local area network communications.
13. The method of claim 8 , wherein in detecting that the interference on the wired media exceeds the interference threshold level, the method further comprises detecting that a signal quality available on the wired media falls is less than at least one of a Signal to Interference Ratio (SNR) threshold level, a Bit Error Rate (BER) threshold level, or a Block Error Rate (BLER) threshold level.
14. The method of claim 8 :
further comprising equalizing incoming data using a Decision Feedback Equalizer (DFE); and
wherein retraining the transceiver using the known data comprises retraining the DFE using the known data.
15. A method of operating a vehicle communication network device comprising:
buffering data for transmission to a remote transceiver of another vehicle communication network device via a transceiver and wired media;
detecting interference on the wired media that exceeds an interference threshold level by determining that a number of soft decisions that fall into a sliding soft decision error window exceeds an error threshold;
upon the detection, entering a quiet mode during which no data is transmitted on the wired media and determining buffered data that was likely corrupted by the interference;
after exiting the quiet mode, entering an idle mode during which known data is transmitted on the wired media;
receiving known data from the remote transceiver;
retraining the transceiver based upon the known data; and
after retraining the transceiver, exchanging data with the remote transceiver including retransmitting the determined buffered data.
16. The method of claim 15 , wherein the wired media comprises an unshielded twisted pair wire.
17. The method of claim 16 , further comprising providing power to the remote transceiver via the unshielded twisted pair wire.
18. The method of claim 15 , further comprising the transceiver supporting wired local area network communications.
19. The method of claim 15 , wherein in detecting that the interference on the wired media exceeds the interference threshold level, the method further comprises detecting that a signal quality available on the wired media falls is less than at least one of a Signal to Interference Ratio (SNR) threshold level, a Bit Error Rate (BER) threshold level, or a Block Error Rate (BLER) threshold level.
20. The method of claim 15 :
further comprising equalizing incoming data using a Decision Feedback Equalizer (DFE); and
wherein retraining the transceiver using the known data comprises retraining the DFE using the known data.