EPCglobal Class-1 Generation 2 UHF RFID Todd Humes, CTO Impinj, Inc. 501 N 34th Street, Suite 100 Seattle, WA 98103 todd.humes@impinj.com

An RFID Chip More transistors than the processor in a 1985 IBM PC-AT Lower power consumption than a honeybee’s brain

RFID Hardware Overview Wafers Tags Reader

RFID is Old, what’s New New standards at UHF (900 MHz) vs HF (13.56MHz) UHF - 10X range of HF RFID Faster data rates – up to 640kbps But, presents many new challenges: How to identify and read/write single tags from hundreds within a reader field... Tag and reader RF interference... Security.... Tag data processing... Solution - EPCglobal Gen2 standard

Example data exchange: RFID Systems Network layer Air Interface RFID Reader Tag Tag IP Network RFID Reader Tag Tag RFID Reader Example data exchange: Forward Return Link parameters Tag inventory Link rates and encoding formats Singulation parameters, tag identification

What do I do? Tag Identification Suppose…you are all tags You are all blindfolded You are nearly deaf You talk by whispering You can’t hear each other Suppose…I’m a reader I’m blindfolded I don’t know who is in the room I need to yell so you can hear me If two of you talk at once, I can’t understand you I’m not allowed to say your name I may hear many others like me screaming in the same room I need to identify everybody in the room What do I do?

Reader Environments Operating Environment Single-reader environment A region within which a reader’s RF transmissions are attenuated by less than 90dB (roughly a sphere with a 1km radius) Single-reader environment A single reader operating in the environment Multiple-reader environment # of simultaneously active readers < # of available channels Example: 10 readers operating in 50 channels Dense-reader environment # of simultaneously active readers  # of available channels Example: 50 readers operating in 50 channels Readers require knowledge of operational deployment and the ability to adjust their RF parameters for a given environment -ie. One non-dense reader in a dense reader deployment will spoil the whole frequency plan

Air Interface Control Gen2 features Purpose S/W Control Tag selection and identification Singulation control and options for faster inventories Q-algorithm, Boolean selection, truncated replies Dense reader mode Allows for a large number of closely spaced readers with minimal interference and optimized data rate for high noise or high speed comm Forward link options – DSB-ASK, SSB-ASK, PR-ASK Return link options – Baseband or subcarrier backscatter Sessions Multiple readers talk within same tag population e.g. dock door reader + handheld Choice of four sessions Variable data rates Link closure in varied environments Configure forward link (Tari, pulsewidth) and reverse link (preamble type, data rate, encoding - FMO or Miller) Kill and access password Security Password validation and management