Can an NFC phone act as an RFID Tag, which can be read at distances higher than 4 inches?
android, nfc, rfid
Solution
NFC is especially limited to the 4 inch distance. Because the Near Field Communication is seen as a "approved communication" between the two partners it is not designed to be used as a tracing device like RFID is used in stores for example.
Thus you can use NFC as a RFID device the distance would still be limited to the 4 inches by the hardware in the phones.
// edit
you could instead use the new Bluetooth 4.0 Protocol. The Setup-Time between Communication Partners is as fast as NFC (<0.1s) (in contrast to Bluetooth 2.1 with almost up to 6s)
Problem
To be more specific, I'm trying to implement an Android application, which forces the phone to operate as an RFID tag. This tag is read by scanners placed around doors (thus the > 4 inches constraint) identifying the person and his whereabouts. The phone will act as a smart tag, thus providing further use cases. Thank you.