Description
RFID (Radio-Frequency Identification) is the older cousin of BLE for indoor identification: passive tags backscatter a reader's interrogation signal, and the reader extracts identity + RSSI / phase. UHF RFID (860-960 MHz, EPC Gen2) is the variant most commonly used for indoor localization research because passive tags are battery-free and pennies each, and the reader exposes per-tag phase that supports cm-scale localization (e.g. Tagoram-class systems). For the thesis it is a comparison baseline to BLE — same problem (indoor localization), different physical layer with different cost / range / accuracy trade-offs.
Specs / capabilities
- LF (125 kHz), HF / NFC (13.56 MHz), UHF (860-960 MHz)
- UHF passive: ~10 m range, hundreds of tags per second per reader
- Tag-side: backscatter modulation, no battery, ~$0.05 per tag
- Reader-side: per-tag RSSI, phase, RF Doppler in research-grade readers (Impinj Speedway R420)
- EPC Gen2 protocol (ISO/IEC 18000-63)
Tooling
- Impinj Octane SDK / LLRP protocol
- Open-source LLRP libraries (
llrp_proto,sllurp)
Used by (papers)
- Indoor RFID localization papers (Tagoram, RF-IDraw, etc.) — comparison vs BLE / CSI
- Crowd / inventory tracking applications