rfid technical issues

1Fall 2007 RFID – Technical Issues

RFID Technical Issues

Operations & Decision TechnologiesDepartment

Kelley School of Business Indiana University


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


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


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.)


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


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


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


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


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


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?


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


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


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


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


Structure of a Tag

Chip + Antennae + Substrate = TagChip or Integrated Circuit (IC)

Antenna


An RFID Tag


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


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


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


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


Some Passive Tags


Some Active Tags


Tag Packaging Formats

• Weather-proof or environment-proof enclosures

• Pressure sensitive labels

• Credit card size flexible labels

• Tokens and coins

• Embedded tags

• Paper tags


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


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


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


Ultra High Frequency Tags


• 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


Microwave Tags


• 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


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


A Passive and an Active Reader


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


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


An Antenna Tunnel

Verification Verification tunnel readstunnel readsVerification Verification tunnel readstunnel readsAntennasAntennasAntennasAntennas


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


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


RFID Players – Hardware

• Alien Technology

• Intermec Technology

• Matrics, Inc.

• Savi Technology

• SAMSys Technologies

• Symbol Technologies

• Texas Instruments


RFID Players - Software

• Manhattan Associates

• SAP

• RedPrairie

• JDA Software

• Manugistics

• EXE Technologies


RFID - Middleware

• TIBCO Software

• Sun Microsystems

• webMethods

• GlobeRanger

• ConnecTerra


RFID – Systems Integrators

• IBM Global Services

• Accenture

• Cap Gemini Ernst and Young

• Sapient

• Kurt Salmon Associates

• The ePC Group

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