RFID has its own vocabulary, and vendors rarely stop to define it. This glossary explains the terms you will meet while scoping, buying or running an RFID project — in plain English, grouped so you can find them fast. New to the technology? Start with RFID basics, then use this as a reference.
Core concepts
- RFID (Radio-Frequency Identification). Identifying and tracking items using radio waves between a tag and a reader — no line of sight required.
- Tag / transponder. The device attached to an item, holding a chip and an antenna. See types of RFID tags.
- Reader / interrogator. The device that powers tags and reads/writes their data. Fixed, handheld and gate readers exist.
- Antenna. Radiates the reader’s signal and receives tag replies; its gain and polarisation shape the read zone.
- IC / chip. The integrated circuit on the tag that stores data and handles the radio protocol.
- Inlay. The chip-plus-antenna assembly on a thin substrate, before it becomes a finished label or tag.
Power and range
- Passive tag. No battery; powered by the reader’s signal. Cheap, long-lived, range up to ~10–15 m on UHF.
- Active tag. Battery-powered; broadcasts on its own. Range up to ~100 m; enables real-time location.
- Semi-passive / BAP (battery-assisted passive). Battery powers the chip, but the tag still replies using the reader’s energy.
- Read range. The distance at which a tag reliably reads — set by frequency, tag, reader power and antenna. See how to improve read range.
- Sensitivity. How little power a tag or reader needs to operate; higher sensitivity means longer range.
Frequencies and standards
- LF (Low Frequency, 125–134 kHz). Short range, robust near liquid/metal; animal ID, access.
- HF (High Frequency, 13.56 MHz). Short range with good memory/security; cards, access, payments.
- NFC (Near-Field Communication). A subset of HF for tap interactions with phones and readers.
- UHF (Ultra-High Frequency, 865–867 MHz in India). Long range, bulk reading; inventory, assets, logistics. See RFID frequencies.
- EPC (Electronic Product Code). A standard identifier scheme for items, stored on the tag.
- EPC Gen2 / ISO 18000-6C. The dominant UHF air-interface standard defining how UHF tags and readers talk.
- RAIN RFID. The industry alliance and marketing term for UHF (EPC Gen2 / ISO 18000-6C) RFID.
- Gen2v2 / Gen2v3. Successive revisions of the EPC Gen2 UHF standard by GS1. Gen2v2 added security features such as tag authentication and untraceable/privacy modes; Gen2v3 is the later revision that, as reported, extends and clarifies these capabilities. Most tags in the field remain plain Gen2 compatible.
- Gen2X. A set of extensions to the Gen2 protocol promoted by Impinj (and, as of 2026, reported to be licensed to other chipmakers) aimed at faster and more reliable reads in dense-tag and moving-item environments. It works alongside standard Gen2 rather than replacing it, and needs Gen2X-capable readers and chips to deliver its benefits.
- ISO/IEC 18000-63. The current ISO designation for the UHF EPC Gen2 air interface (previously referenced as 18000-6C); you will see either name in tender specs.
- ISO 14443 / 15693. Common HF standards for proximity and vicinity cards.
- WPC / 865–867 MHz. India’s Wireless Planning & Coordination allocation for licence-exempt UHF RFID. See the BIS & WPC compliance guide.
Tag memory and data
- EPC memory. The bank holding the item’s identifier.
- TID (Tag Identifier). A unique, factory-locked serial for the chip itself — useful for anti-cloning.
- User memory. Optional rewritable space for extra data on the tag.
- Encoding. Writing data (such as a serial or EPC) to a tag.
- Serialization. Giving every unit a unique identity, enabling item-level tracking.
Reading behaviour
- Anti-collision. The protocol that lets a reader single out and read many tags in the field without them jamming each other.
- Bulk / simultaneous read. Reading hundreds of tags in one pass — RFID’s defining advantage over barcode.
- Dwell time. How long a tag stays in the read zone; too short and reads are missed.
- Read rate / accuracy. The share of present tags actually read; the number that decides inventory quality.
- Phantom / stray read. An unwanted read of a tag outside the intended zone.
- Orientation sensitivity. How much tag angle relative to the antenna affects reads (mitigated by circular-polarised antennas).
Hardware and deployment
- Fixed reader. A mounted reader with external antennas for a portal, conveyor or shelf.
- Handheld reader. A portable (often Android) reader for audits and field reads.
- Integrated reader. Reader and antenna in one enclosure for long-range points.
- Gate / portal reader. A doorway setup that reads everything passing through — goods-in/out, access.
- Polarisation (linear vs circular). Antenna field shape; circular tolerates varied tag orientation, linear gives more range in a fixed orientation.
- dBi / dBm. Antenna gain (dBi) and radiated power (dBm) — higher generally means longer range, within legal limits.
- On-metal tag. A tag engineered to read when mounted on metal, which detunes ordinary tags.
- RTLS (Real-Time Location System). Continuous live positioning of tagged assets/people using active or BLE tags.
- Middleware / SDK. The software layer between readers and your application; a good SDK speeds integration.
Compliance and quality
- BIS (Bureau of Indian Standards). Product safety/conformity certification; required for many electronics sold in India.
- WPC approval. Confirmation that radio equipment conforms to India’s spectrum rules for the band.
- IP rating. Ingress protection against dust and water for rugged tags and readers.
Missing a term? Ask us — we will define it and point you to the right hardware for what you are trying to build.