EPC Gen2

Standards & Protocols

Second-generation EPC protocol for UHF RFID defining the air interface, standardized internationally as ISO/IEC 18000-63.

EPC Gen2

epc-gen2/" class="glossary-term-link" data-term="EPC Gen2" data-definition="UHF RFID air interface standard." data-category="Standards & Protocols">EPC Gen2 (formally GS1." data-category="Standards & Protocols">EPCglobal UHF Class 1 Generation 2, standardised internationally as ISO 18000-63) is the dominant air interface protocol for UHF RFID operating in the 860-960 MHz band. It defines how readers and passive tags communicate, covering everything from physical-layer signalling to application-level commands.

Protocol Layers

Layer Specification Content
Physical Modulation, encoding, timing Reader: DSB-ASK/SSB-ASK/PR-ASK; Tag: FM0/Miller
Tag identification Singulation and anti-collision Q-algorithm with adjustable slot counts
Tag access Memory read/write, lock, kill Four memory banks, access password, kill password
Security (v2) Authentication, privacy Crypto suite, untraceable, tag auth

Inventory Process

A Gen2 inventory round proceeds as follows:

  1. Select -- the reader issues Select commands to filter the tag population (e.g., only tags in a specific EPC range).
  2. Query -- the reader begins an inventory round, specifying a session flag (S0-S3) and the Q parameter (2^Q time slots).
  3. Singulation -- each tag picks a random slot; if only one tag responds in a slot, the reader reads its data. Collisions trigger the tag to repick.
  4. ACK -- the reader acknowledges a successfully singulated tag, which then transmits its full EPC.

Gen2v2 Enhancements

The 2015 revision (Gen2v2) added cryptographic security features: mutual authentication using AES-128, the untraceable command for consumer privacy, and secure tag authentication to combat cloning. These features are marketed by RAIN RFID as enabling brand protection and anti-counterfeiting.

Why Gen2 Matters

EPC Gen2 is the lingua franca of UHF RFID. Any reader from Impinj, Zebra, Alien, or ThingMagic can communicate with any Gen2-compliant tag from any manufacturer. This interoperability has driven tag prices below $0.05 at billion-unit volumes and enabled global-scale deployments.

See also: RAIN RFID | ISO 18000-63 | Standards

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Perguntas frequentes

The RFID glossary is a comprehensive reference of technical terms, acronyms, and concepts used in Radio-Frequency Identification technology. It is designed for engineers, system integrators, and project managers who work with RFID and need clear definitions of terms like EPC, backscatter, anti-collision, and ISO 18000.

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