Device: Samsung/Google Nexus S I9023 Carrier: - Country / Language: Austria /German OS / Browser / build number (if applicable): Android 2.3.4
Hello, I am using the Nexus S (Android 2.3.4) with the NFC functionality to test an NFC tag. This tag does some cryptographic operations (e.g. signing a challenge) which are quite time consuming. The ISO14443-4 standard says that an NFC reader waits a specific time for the answer of the tag before a timeout occurs. This time is called FWT (frame waiting time). To extend this waiting time a waiting time extension (WTX) can be used by the tag. So before the tag starts a time consuming operation it sends a WTX to the reader. The reader confirms the longer waiting time by sending the same WTX back to the tag and for the next answer the timeout is increased. By receiving the answer to the WTX the tag can start the time consuming operation. As we figured out it seems that the Nexus S does not handle the WTX correctly. When receiving a WTX it is correctly answered with the same WTX by the phone but the temporary FWT does not increase. So I always get an Exception (IOException: transceive failed!) when the tag performs some time consuming operation. It seems to me that the Nexus S does not increase the waiting time for the next answer of the tag after receiving a WTX! The implementation on the tag is correct as it works with all the other readers I have used! I also tried the setTimeout method but it seems not to have an influence on the waiting time! Does anybody have an idea how to solve this issue? Do developers of the phone read this forum or does anybody know some contact data where to report this problem additionally?