1Fall 2007 RFID – Technical Issues
RFID Technical Issues
Operations & Decision TechnologiesDepartment
Kelley School of Business Indiana University
222Fall 2007 RFID – Technical Issues
What is RFID?
• RFID stands for Radio Frequency Identification
• It is a technology that permits contact-free transfer of data using a radio frequency transmission
• The heart of RFID technology is a transponder, which is a silicon chip attached to an antenna. It is called a tag. The tag can be attached to items that are to be tracked
• A numeric code is stored on the chip. This code is called the electronic product code (EPC)
• The code is read when communication takes place between a reader (interrogator) and the tag
333Fall 2007 RFID – Technical Issues
RFID Technology is Not New!!
• Tracking livestock (Approximately 15 years)
• Contactless payments (Approximately 5 years)
ExxonMobil Speedpass
Tollbooth lanes
• Event access (Ticketing)
• Building access control
• Has been used in manufacturing to track large components such as engines and chassis
• Has been used for the international postal system for monitoring the quality of service
444Fall 2007 RFID – Technical Issues
Why Now?
• The creation of the Electronic Product Code (EPC)
• Technology changes
• EPCGlobal Generation 2 standard (Gen 2)
• The price of the tags has been coming down. However, price is still an issue
• Mandates by various organizations (European Parliament, DOD, Wal-Mart, Target, etc.)
555Fall 2007 RFID – Technical Issues
The Wal-Mart Mandate
• Wal-Mart required its top 100 suppliers to be RFID-enabled at the case and pallet level by January 2005
• The rest of its suppliers had to be compliant by December 2006
• Wal-Mart did not endorse specific RFID hardware or software
• Expected suppliers to perform their own tests of RFID technologies
• Will impact 10,000+ Suppliers
666Fall 2007 RFID – Technical Issues
Advantages of RFID
• Provides non-contact, non-line-of-sight operation
• Is difficult to counterfeit
• Is a highly capable and proven technology for a wide range of applications
• Provides an instantaneous read of code
777Fall 2007 RFID – Technical Issues
RFID Technology is Maturing
• Technology has improved significantly
• Standards are being adopted and agreed upon
• Some markets are maturing
• Other markets being identified for possible applications
• Significant impact expected in SCM
888Fall 2007 RFID – Technical Issues
RFID Systems
• Tags are attached to objects
• Each tag has a certain amount of internal memory in which it stores information about the object
• This information could be unique ID numbers, details about manufacture date and product composition
999Fall 2007 RFID – Technical Issues
RFID Systems
• When the tags pass through a field generated by a reader, they transmit information back to the reader, identifying the object.
• Until recently the tags and readers were used in systems with low volumes but the objective is to use them in high volume situations
101010Fall 2007 RFID – Technical Issues
Possible Roadblocks
• Tag reading efficiencies and prices
• Standards - Applications are global but the basis of radio regulations are national and even regional
• Interoperability of the technologies through the supply chain
• Who bears the cost of the RFID system in the supply chain?
111111Fall 2007 RFID – Technical Issues
Possible Roadblocks
• The barrier points for tags are 2 meters for range and 3GHz for frequency. Below these points, it is possible to make a low cost tag system. Beyond these points, technologies get more expensive
• IT Infrastructure to handle the large amounts of data
• Change of work and labor practices
• Privacy and ethical issues
• Security issues
121212Fall 2007 RFID – Technical Issues
Improvements in RFID Technology
• From read-only tags to read-write
• From no memory in tags to 2K, 8K and in some cases 16K bits
• Better authentication between tag and reader
• Anti-collision algorithms for multiple tag reads in the field
• More sophisticated security algorithms
131313Fall 2007 RFID – Technical Issues
An RFID System
Host Computer
ControlModule
BroadcastInterface
Transponder
Reader
Data Transmitted
Request
Transmitted
Data Requested
Data Received
Command to
Retrieve Data
Data sent to
Host Internet /
Intranet
141414Fall 2007 RFID – Technical Issues
RFID Tags
• Tags can be either active (powered by a battery) or passive (powered by the reader field)
• Tags can also be semi-active or semi-passive (same type of tag). Such tags have batteries but are only activated by a reader’s electromagnetic field
• Tags come in various forms including smart cards, tags, labels, watches, and even embedded in cell phones
151515Fall 2007 RFID – Technical Issues
Structure of a Tag
Chip + Antennae + Substrate = TagChip or Integrated Circuit (IC)
Antenna
161616Fall 2007 RFID – Technical Issues
An RFID Tag
171717Fall 2007 RFID – Technical Issues
RFID Operating Frequencies
• Low Frequency (125-134kHz)Used in access control, livestock, race timing, pallet tracking, wireless commerce
• High Frequency (13.56 mHz)Smart labels – Used in supply chain, wireless commerce, ticketing, product authentication
• Ultra-High Frequency – UHF (900+mHz)Emerging technology
• Microwave (2.45 gHz)Not widely deployed
181818Fall 2007 RFID – Technical Issues
RFID Transponder or Tags
• It is a micro-chip with a unique ID code (UID) and memory
• It also has an antenna which is usually copper or aluminum
• Active tags versus passive tags
• Some chipless tags – very low cost, short read range tags
191919Fall 2007 RFID – Technical Issues
Readability Issues
• Dead Tags – Unreadable
• Quiet Tags – Readable but only at a short distance
• Quality of tags is an issue
• Readability rates of higher quality tags are at about 97% to 98%. That translates to about 2 Sigma
202020Fall 2007 RFID – Technical Issues
Electronic Product Code
• Header: Identifies the EPC’s Version Number
• EPC Manager: Indicates the enterprise using the EPC number
• Object Class: Refers to the class or category of a product (similar to a Stock Keeping Unit – SKU)
• Serial Number: Identifies a unique item being tagged
647.37000.123456.100000000Header8 Bits
EPC Manager34 Bits
Object Class20 Bits
Serial Number34 Bits
212121Fall 2007 RFID – Technical Issues
Some Passive Tags
222222Fall 2007 RFID – Technical Issues
Some Active Tags
232323Fall 2007 RFID – Technical Issues
Tag Packaging Formats
• Weather-proof or environment-proof enclosures
• Pressure sensitive labels
• Credit card size flexible labels
• Tokens and coins
• Embedded tags
• Paper tags
242424Fall 2007 RFID – Technical Issues
Transponder/Tag Classes
• Read Only
• Write Once Read Only
• Read/Write
• Read/Write with On-Board Sensors (for recording parameters such as temperature, pressure, etc.)
• Read/Write with Integrated Transmitters – Can communicate with other tags and devices without the presence of a reader
252525Fall 2007 RFID – Technical Issues
Low Frequency Tags
• Typical Maximum Read Range - <0.5 m
• Relatively expensive even at high volumes. Low frequency requires a longer more expensive copper antenna. Least susceptible to performance degradations from metal and liquids
• Generally passive tags
• Applications include access control, animal tracking, POS applications including SpeedPass
• Data rate slower than other frequencies
• Passive tag size is larger than other frequencies
262626Fall 2007 RFID – Technical Issues
High Frequency Tags
• Typical Maximum Read Range – Approx 1m
• Less expensive than low frequency tags. Best suited for applications that do not require long range reading of multiple tags
• Generally passive tags
• Applications include item-level tracking such as baggage handling (non-US)
• Data rate slower than other ultra high frequencies (UHF)
• Passive tag size is larger than UHF
272727Fall 2007 RFID – Technical Issues
Ultra High Frequency Tags
• Typical Maximum Read Range – Approx 3m
• In large volumes, UHF tags have the potential to be cheaper than either LF or HF tags. Offer balance between range and performance
• Active tags with integral battery or passive tags
• Applications include pallet tracking and item-level tracking such as baggage handling (US)
• Data rate faster than other LF or HF tags
• Passive tag size is smaller than LF or HF tags
282828Fall 2007 RFID – Technical Issues
Microwave Tags
• Typical Maximum Read Range – Approx 1m
• Very similar to UHF tags but with faster read rates. Most susceptible to performance degradations from metal and liquids, particularly metal
• Active tags with integral battery or passive tags
• Applications include SCM And toll collection
• Data rate faster than other ultra high frequencies (UHF)
• Passive tag size is smaller than UHF tags
292929Fall 2007 RFID – Technical Issues
RFID Readers
• Readers are radio frequency devices that:
Transmit and receive RF signals
Contain a control unit to execute commands
Incorporate an interface to transfer data
Receives commands from a Host computer
Responds to software commands from Host
303030Fall 2007 RFID – Technical Issues
A Passive and an Active Reader
313131Fall 2007 RFID – Technical Issues
Reader Characteristics
• Stationary or Hand-held
• Multi-protocol?
• Weather-proof?
• Read ranges vary from a few centimeters to a few meters
• Read range is dependent upon broadcast signal strength, size of broadcast antenna, size of transponder antenna, and the environment
323232Fall 2007 RFID – Technical Issues
Antenna Characteristics
• Transmits and receives RF signals
• Typically made of copper or aluminum, new technologies emerging for printed antennas
• Stationary or Hand-held
• Weather-proof?
• Fixed or Turnable
333333Fall 2007 RFID – Technical Issues
An Antenna Tunnel
Verification Verification tunnel readstunnel readsVerification Verification tunnel readstunnel readsAntennasAntennasAntennasAntennas
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RFID System Issues
• Read Distance Requirements
Long read range
Short read range
• Frequency
All frequencies have their pros and cons
• ISO Standards
Proprietary or Standards-based
353535Fall 2007 RFID – Technical Issues
RFID System Issues
• Government Regulations
Varies from country to country
• Multiple Tag Reading in Same Field
Anti-collision algorithms
• Hardware set-up
Environment can affect performance
• Transponders
363636Fall 2007 RFID – Technical Issues
RFID Players – Hardware
• Alien Technology
• Intermec Technology
• Matrics, Inc.
• Savi Technology
• SAMSys Technologies
• Symbol Technologies
• Texas Instruments
373737Fall 2007 RFID – Technical Issues
RFID Players - Software
• Manhattan Associates
• SAP
• RedPrairie
• JDA Software
• Manugistics
• EXE Technologies
383838Fall 2007 RFID – Technical Issues
RFID - Middleware
• TIBCO Software
• Sun Microsystems
• webMethods
• GlobeRanger
• ConnecTerra
393939Fall 2007 RFID – Technical Issues
RFID – Systems Integrators
• IBM Global Services
• Accenture
• Cap Gemini Ernst and Young
• Sapient
• Kurt Salmon Associates
• The ePC Group