RFID Technology & Application

Auto-ID Technologies

Outline RFID Overview RFID Technology Internals RFID Applications RFID Issues RFID Case study

RFID Overview

What is RFID? RFID = Radio Frequency IDentification – Uses radio-frequency waves to transfer data between a reader and a movable item to identify, categorize, track.. – Does not require physical sight or contact between reader/scanner and the tagged item. – Attempts to provide unique identification and backend integration that allows for wide range of applications.

RFID System Components Tag – Chip – Antenna Reader – RF Module (Transmitter and Receiver) – Control Unit – Antenna – Several Interfaces (RS 232, USB, etc.) Host Computer – Middleware

RFID System Components

RFID Tag Structure(General) Antenna Power Supply Tx Modulator Rx Demodulator Control Logic (Finite State machine) Memory Cells Tag Integrated Circuit (IC)

RFID Tags – Smart Lables … and a chip attached to it … on a substrate e.g. a plastic foil... An antenna, printed, etched or stamped... A paper label with RFID inside

RFID Tags – More Examples

RFID Tag Types Passive Tags – Operational power from reader radiated power Active Tags – Operational power provided by battery(built into tag)

RFID Tag Comparison PassiveActive Power Source Powered by reader Battery powered Read Range Shorter (4 inches to 15 feet) Longer (300 feet) Data Rate Lower data rateHigher data rate Storage Lower (few bits to 1 KB) Higher (512 KB) NoiseSubject to noiseBetter noise Immunity CostsAround 25 cents to few dollars Around 50 to 250 dollars

RFID Readers Functions: – Remotely power tags – Establish a bidirectional data link – Communicate with networked server(s) – Can read tags per second Readers can be at a fixed point such as – Entrance/exit – Point of sale Readers can also be mobile/hand-held

RFID Reader Structure

RFID Readers - Anatomy 915MHz Radio Network Processor Digital Signal Processor (DSP) 13.56MHz Radio Power Supply

RFID Readers - Examples

RFID Tech Internals

Information Acquiring Methods Inductive Coupling – For getting data from proximity card – passive tags Propagation Coupling – For reading tags working in a larger distance

Inductive Coupling Based on the stored data, the micro chip of the tag controls the switching on and off of a load resistance which will influence the voltage in the reader’s antenna. Then the reader can detect the voltage changes in its own antenna.

Inductive Coupling The electro-magnetic field from the reader penetrates the coil of the tag in a shorter distance. By induction, a voltage is generated in the tag’s antenna coil. This voltage is rectified and servers as the power of the tag.

Inductive Coupling Inductive Coupling - shorter distance Transceiver Tag Reader antenna RFID Tag IC or microprocessor antenna

Propagation Coupling Basic Principle: – The electromagnetic waves are reflected by objects with dimensions greater than around half the wavelength of the wave.

Propagation Coupling A small portion of the electromagnetic power of the reader reaches the tag. This power can be also used as the power supply for the tag (passive tag). Based on the stored data, the micro chip alters the load connected to the tag’s antenna and then changes the reflection characteristics of the antenna. Then the reflected RF energy arrives at the reader’s antenna.

Propagation Coupling Propagation Coupling – longer distance Transceiver Tag Reader antenna RFID Tag IC or microprocessor antenna

Data Transfer Amplitude Shift Keying (ASK) – Changing the amplitude of the radio wave based on the digital (binary ) data Frequency Shift Keying (FSK) – Switching between two different frequencies based on the digital (binary) data Phase Shift Keying (PSK) – Changing the phase on the transition between a 0 to 1 or 1 to 0

RFID Communications Tags Reader Power from RF field Reader Antenna Commands from reader Tag->Reader Responses RFID Communication Channel

RFID Frequencies BandRangeData speedPower SourceRemarks KHz (LF)< 10 cmLow Generally passive tags Animal identification, factory data collection MHz (HF)< 1 mLow to moderate Generally passive tagsSmart cards 433 MHz (UHF)1-100 mModerate Active tags or passive tags Defence applications, with active tags MHz (Europe) MHz (North America) UHF 1-2 m Moderate to high Active tags or passive tags Various standards 2450 MHz 5800 MHz (microwave) 1-2 mHigh Active tags or passive tags WLAN, Bluetooth standards 3.1 Ghz-10 GHz (microwave) to 200 mHighActive tagsRequires active tags

RFID Frequency Trade-Offs Frequency Lifespan Range Power Cost Bandwidth Line of Sight

RFID Applications

RFID Application Manufacturing and Processing – Inventory and production process monitoring – Warehouse order fulfillment Supply Chain Management – Inventory tracking systems – Logistics management Retail – Inventory control and customer insight – Auto checkout with reverse logistics

RFID Application Security – Access control – Counterfeiting and Theft control/prevention Location Tracking – Traffic movement control and parking management – Wildlife/Livestock monitoring and tracking

RFID Application – Smart Groceries Add an RFID tag to all items in the grocery As the cart leaves the store, it passes through an RFID transceiver. The cart is rung up in seconds.

RFID Application – Smart Cabinet 1.Tagged item is removed from or placed in “Smart Cabinet” 3.Server/Database is updated to reflect item’s disposition 4.Designated individuals are notified regarding items that need attention (cabinet and shelf location, action required) 2.“Smart Cabinet” periodically interrogates to assess inventory Passive read/write tags affixed to caps of containers Reader antennas placed under each shelf

RFID Application – Smart Fridge Recognizes what’s been put in it Recognizes when things are removed Creates automatic shopping lists Notifies you when things are past their expiration Shows you the recipes that most closely match what is available

More Smart Applications “Smart” products – Clothing, appliances, CDs, etc. tagged for store returns “Smart” paper – Airline tickets that indicate your location in the airport “Smart” currency – Anti-counterfeiting and tracking. “Smart” people? “Smart” planet? …

RFID Issues

Reader Collisions It occurs when the coverage area of one reader overlaps with that of another reader. The RF fields of two or more readers may overlap and interfere. Tag Reader 1 Reader 2

Reader Collisions TDMA based solutions: – Program the reader to read at fractionally different times – Assign different time slots to nearby readers Other solutions?

Tag Collisions It occurs when multiple tags are in range of the reader. All the tags will be activated and respond at the same time. – Signal interference may occur. – It is difficult to distinguish between the tags. Tag2 Reader Tag4 Tag3 Tag1

Security Issues - Eavesdrop ReaderTagEavesdropper Forward Channel Range Backward Channel Range

Other Security Issues Forge valid tags Attack the RFID infrastructure Wiping out inventory data Interrupting the normal reading

RFID – The complete picture

RFID Case Study

TRF7960A EVM ISO/IEC Demo

TRF7960A EVM TRF7960A Evaluation Module – Texas Instrument – Multiple protocol RFID reader – For RFID study and research – Build RFID applications – $101

TRF7960A EVM Features – Support ISO 15683, A&B, Tag-it protocol – Has an on-board PCB antenna – Has an interface for testing – Provides a Windows based host UI – Provides a USB interface – Provides source codes & detailed docs

TRF7960A EVM

RF Test Interface – Use SMA connector – For reader testing – External amplifier or antenna – Should remove one specific resistor

ISO 14443

ISO/IEC – Proximity integrated circuit cards – Four parts Physical characteristics Frequency & Power & Signal interface Initialization & Anticollision Transmission protocols – Communication interface Type A Type B

ISO ISO/IEC – Proximity integrated circuit cards, up to 10cm – Four parts Physical characteristics Frequency & Power & Signal interface Initialization & Anticollision Transmission protocols – Communication interface Type A Type B

ISO Type A & B Reader to Card (PCD > PICC)Type AType B Frequency13.56 MHz13.56 MHz Modulation 100% ASK10% ASK Bit codingModified MillerNRZ Data rate 106 kb/s106 kb/s Card to Reader (PICC > PCD) ModulationLoadLoad Bit codingOOKBPSK Subcarrier847kHz847kHZ Bit codingManchesterNRZ Data rate106 kb/s106 kb/s

ISO Type A & B

Demo

References [1] [2] Introduction to RFID. Vlad Krotov. Uni. of Houston, Bauer College of Busines. [3] [4] RFID Handbook.Ramiro Liscano. “Introduction to Bluetooth Networking ”. [5]