4 RFID is Old, what’s NewNew standards at UHF (900 MHz) vs HF (13.56MHz)UHF - 10X range of HF RFIDFaster data rates – up to 640kbpsBut, 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
5 Example data exchange: RFID SystemsNetwork layerAir InterfaceRFID ReaderTagTagIPNetworkRFID ReaderTagTagRFID ReaderExample data exchange:ForwardReturnLink parametersTag inventoryLink rates and encoding formatsSingulation parameters, tag identification
6 What do I do? Tag Identification Suppose…you are all tags You are all blindfoldedYou are nearly deafYou talk by whisperingYou can’t hear each otherSuppose…I’m a readerI’m blindfoldedI don’t know who is in the roomI need to yell so you can hear meIf two of you talk at once, I can’t understand youI’m not allowed to say your nameI may hear many others like me screaming in the same roomI need to identify everybody in the roomWhat do I do?
7 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 environmentA single reader operating in the environmentMultiple-reader environment# of simultaneously active readers < # of available channelsExample: 10 readers operating in 50 channelsDense-reader environment# of simultaneously active readers # of available channelsExample: 50 readers operating in 50 channelsReaders 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
8 Air Interface Control Gen2 features Purpose S/W Control Tag selection and identificationSingulation control and options for faster inventoriesQ-algorithm, Boolean selection, truncated repliesDense reader modeAllows for a large number of closely spaced readers with minimal interference and optimized data rate for high noise or high speed commForward link options – DSB-ASK, SSB-ASK, PR-ASK Return link options – Baseband or subcarrier backscatterSessionsMultiple readers talk within same tag populatione.g. dock door reader + handheldChoice of four sessionsVariable data ratesLink closure in varied environmentsConfigure forward link (Tari, pulsewidth) and reverse link (preamble type, data rate, encoding - FMO or Miller)Kill and access passwordSecurityPassword validation and management