UNIT PPT - 20EC7020E -RFID AND FLEXIBLE SENSORS

20EC7020E -RFID AND
FLEXIBLE SENSORS
Prepared by,
Mrs.VIDHYA V,
AP/AI&DS

UNIT- I
INTRODUCTION AND RFID ARCHITECTURE
Case for RFID
Eras of RFID – applications
RFID Architecture
Confluence of technologies
Key functionalities
System components
Systemic quality considerations
Architecture guidelines
System Management.

INTRODUCTION TO RFID
• Identification plays a major function in our lives, the operations
that we run, and even businesses.
• Identification and/or authentication is essential in most, if not
all, of the objects, people, or procedures that we deal with on a
daily basis.
• Examples include: barcode technology for identifying groceries,
vehicle identification numbers (VIN) for recognizing vehicles,
magnetic stripe cards used for payment methods (like credit
cards), biometrics procedures for identifying humans, and
holography techniques used for the authentication of stamps
and/or money.

• There are several other techniques that are used for
identification/authentication such as: access cards, proximity
cards, contactless smart cards, and radio frequency
identification (RFID), which takes on several forms and may be
used in any other identification or authentication wireless
methods.
• RFID stands for Radio Frequency Identification, a term
that describes any system of identification wherein an
electronic device that uses radio frequency or magnetic field
variations to communicate is attached to an item.

• The two most talked-about components of an RFID system are :
1. Tag
2. Reader
Tag is the identification device attached to the item that needed to track.
Reader is a device that can recognize the presence of RFID tags and
read the information stored on them. The reader can then inform another
system about the presence of the tagged items.
 The system with which the reader communicates usually runs software
that stands between readers and applications. This software is called
RFID middleware.

UNIT PPT - 20EC7020E -RFID AND FLEXIBLE SENSORS

History of RFID
• Decade -Event
• 1940s - Radar refined and used-major World War II development effort.
- RFID invented in 1948.
• 1950s - Early explorations of RFID technology-laboratory experiments.
• 1960s - Development of the theory of RFID.
- Start of applications field trials.
• 1970s -Explosion of RFID development.
-Tests of RFID accelerate.
-Very early adopter implementations of RFID.
• 1980s -Commercial applications of RFID enter main stream.
• 1990s -Emergence of standards.
-RFID widely deployed.
- RFID becomes a part of everyday life

RFID vs. Barcodes
Can identify individual objects
without direct line of sight.
Direct line of sight required for
scanning.
Can scan items from inches to
feet away, depending on type of
tag and reader.
Require closer proximity for
scanning.
Data can be updated in real time. Data is read-only and can’t be
changed.
Require a power source. No power source needed.
Read time is less than 100
milliseconds per tag.
Read time is half a second or
more per tag.
Contain a sensor attached to an
antenna, often contained in a
plastic cover and more costly
than barcodes.
Printed on the outside of an
object and more subject to wear.

RFID Challenges
RFID is prone to two main issues:
• Reader collision: Reader collision, when a signal
from one RFID reader interferes with a second
reader, can be prevented by using an anticollision
protocol to make RFID tags take turns transmitting
to their appropriate reader.
• Tag collision: Tag collision occurs when too many
tags confuse an RFID reader by transmitting data at
the same time. Choosing a reader that gathers tag
info one at a time will prevent this issue

RFID applications
• Pet And Livestock Tracking
• Inventory Management
• Asset Tracking And Equipment Tracking
• Inventory Control
• Cargo And Supply Chain Logistics
• Vehicle Tracking
• Customer Service And Loss Control
• Improved Visibility And Distribution In The Supply Chain
• Access Control In Security Situations
• Shipping
• Healthcare
• Manufacturing
• Retail Sales
• Tap-and-go Credit Card Payments

Advantages of RFID
• Cost effective solution compared to other technologies
• Does not requires direct line of sight to operate
• RFID readers can read hundreds of tags simultaneously
within seconds
• RFID tags can be rewritten and easily reused
• Data from tags can be encrypted for enhanced security
• Tags can store more information than just basic product
information (serial number, lot number manufacturing
date, expiry, and website URL etc…)
• RFID systems can be integrated with other existing
systems
• RFID technology is easily scalable and easy to implement

Disadvantages of RFID
• Signals from the RFID reader can be blocked by
metal surface, liquids and thick materials.
• Higher implementation cost compared to barcode
scanners
• Accuracy is affected due to signal quality (any
obstruction could cause error in data)
• Implementation is more complex than barcode
system
• Privacy and security vulnerabilities often argued
with increased use of tags (especially personal
information)

CASE FOR RFID
• RFID technologies offer practical benefits to almost
anyone who needs to keep track of physical assets.
• Manufacturers improve supply-chain planning and
execution by incorporating RFID technologies.
• Retailers use RFID to control theft, increase efficiency
in their supply chains, and improve demand planning.
• Pharmaceutical manufacturers use RFID systems to
combat the counterfeit drug trade and reduce errors in
filling prescriptions.
• Machine shops track their tools with RFID to avoid
misplacing tools and to track which tools touched a
piece of work.
• RFID-enabled smart cards help control perimeter
access to buildings.

Advantages of RFID over Other Technologies
• There are many different ways to identify objects,
animals, and people.
• People have been counting inventories and
tracking shipments since the Sumerians invented
the lost package.
• Written tags and name badges work fine for
identifying a few items or a few people, but to
identify and direct hundreds of packages an hour,
some automation is required.

• RFID tags provide a mechanism for identifying an
item at a distance, with much less sensitivity to the
orientation of the item and reader.
• A reader can “see” through the item to the tag even
if the tag is facing away from the reader.
• RFID has additional qualities that make it better
suited than other technologies (such as bar codes
or magnetic strips) for creating the predicted
“Internet of Things.”
• One cannot, for instance, easily add information to
a bar code after it is printed, whereas some types of
RFID tags can be written and rewritten many times.
• Also, because RFID eliminates the need to align
objects for tracking, it is less obtrusive.

Some of the benefits of RFID include the following:
1.Alignment is not necessary:
A scan does not require line of sight. This can save time in
processing that would otherwise be spent lining up items.
2.High inventory speeds:
Multiple items can be scanned at the same time. As a
result, the time taken to count items drops substantially.

3.Variety of form factors:
RFID tags range in size from blast-proof tags the size
of lunch boxes to tiny passive tags smaller than a grain
of rice. These different form factors allow RFID
technologies to be used in a wide variety of
environments.
4.Item-level tracking:
Ninety-six-bit RFID tags provide the capability to
uniquely identify billions of items
5.Rewritability:
Some types of tags can be written and rewritten many
times. In the case of a reusable container, this can be a
big advantage.

Promise of RFID
• The capability to attach an electronic identity to a
physical object effectively extends the Internet into the
physical world, turning physical objects into an “Internet
of Things.”
• Rather than requiring human interaction to track assets,
products, or even goods in our homes, applications will
be able to “see” items on the network due to their
electronic IDs and wireless RF connections.

• Some shoppers in Japan use RFID-enabled cell
phones to make purchases from vending machines.
• Businesses use RFID to track goods, and animal
tracking has been around for years.
• RFID will enter the home and the supermarket aisle
when the prices of readers and tags become low
enough and when the information infrastructure to
use and maintain the new technology is in place.

Eras of RFID
• The progress of RFID adoption divides naturally
into following eras:
1. Proprietary Era
2. Compliance Era
3. RFID-Enabled Enterprise Era
4. RFID-Enabled Industries Era
5. Internet of Things Era

Proprietary Era
• For almost 60 years now (triggered by the development of
transistors in 1947), businesses and governmental entities
have used RFID to track items and provide access control
to facilities.
• The smaller size and greater durability of transistors made it
possible to attach transmitters to valuable items, and over
time developments such as improved batteries, integrated
circuits, and microchips reduced the cost of the transmitters
(tags), allowing tracking of less valuable items.
• Some of the applications in this era included the tags used
to track rail cars and the chassis tags that have been used
since the 1980s to track automobiles through an assembly
line. In the 1970s and 1980s, RFID was used for tracking
dairy cattle.

• Expensive, proprietary RFID tags, which were
usually recycled, were a major characteristic of this
era.
• The reuse spread the cost out, such that a single use
might cost only a few cents.
• Some of the systems developed during this era were
technically advanced and tightly integrated into
business processes, but they were characterized by
both poor support for sharing information between
trading partners (incompatible IDs, for instance)
and costly reader and tag components.

Compliance Era
• The steep drop in semiconductor prices and widespread
adoption of broadband networking at the end of the 20th
century triggered an era we call the Compliance era.
• In this era, the U.S. DoD and large retailers such as Wal-
Mart and Tesco began asking their suppliers to tag
pallets (and sometimes individual items) with RFID
tags.
• Their mandates required that the tags conform to
emerging standards.
• The anticipated volume of tags that will be purchased to
meet these mandates has pushed these same standards
much closer to universal adoption, which has greatly
reduced the cost of components.

• The new, less expensive tag technology is still prone
to manufacturing defects, and, due in part to early
implementation of the tag standards, often
Compliance-era tags do not perform as well in
practice
• Thus, while adoption of RFID is on the rise, there
has actually been a slight slump in its capabilities
(in the sense of how the technology is used, if not
the purposes to which it is applied).

RFID-Enabled Enterprise Era
• As standards stabilize and component costs fall,
many organizations will begin to implement RFID
tracking within their internal processes.
• This will allow them to measure the pulse of their
distribution systems for materials, assets, and
products and to keep real-time inventories of items,
such as the location and age of perishable goods.
• During this era, declining costs will inspire a steady
transition from tracking shipping units to tracking
individual items.
• Similarly, portal readers at the door will record the
entry and exit of every item in a shop or warehouse.

• Business integration products and inventory will
begin to fully support individual item tracking.
• However, even with widespread internal adoption
and tagging at the origin of the supply chain, it will
take time for businesses to develop the agreements
and security to allow organizations to share RFID
information with one another (so called business-to-
business, or B2B, communication).
• While businesses will continue to share whatever
B2B information they have shared in the past, the
new RFID information will be used largely within
the enterprise.

RFID-Enabled Industries Era
• In this era, RFID standards, RFID information networks, business
agreements, and comprehensive security and privacy policies will
solidify to the point where entire industries and supply chains can share
appropriate information reliably, trusting that only authorized users can
see any sensitive information.
• Safety overstock inventories will drop, along with fulfillment times and
costs, due to theft and error. Simply knowing “what was where when”
provides a powerful tool for applications that we have only begun to
realize.

Internet of Things Era
• This final era will be triggered by widespread
adoption of RFID technology and the associated
demand for easier management of distributed sensor
networks, as well as by a reduction in the cost of
smart devices and tags.
• Lower costs and greater demand for information
will commercialize existing technologies already in
use so that military and manufacturing applications
can create self-organizing networks of cheap,
expendable components with extremely low
incremental maintenance and management costs.

• This technology will finally make it possible to
adopt RFID technology on retail floors, in farm
fields, and in homes.
• It will expand the group of businesses adopting the
technology to include even the smallest
entrepreneurs.
• In this era, physical objects will be tied to the
Internet through their digital identities.

• The term “autoid,” short for automatic ID, describes
any automated system for attaching an identity to an
item.
• Real-Time Location Systems (RTLSs) are
automated systems for tracking the location of an
item.
• Notice that RFID is related only indirectly to RTLSs
and that RFID is only one type of automated
identity system.

Access Control
• Access control applications are RFID systems used to
selectively grant access to certain areas.
• Example: RFID tags attached to an automobile or held in a
person’s hand as a card, key chain, or wristband may allow
access to a road, building, or secure area.
Considerations
• Anti-counterfeiting: Counterfeit tags must be recognized and
attempts to use or manufacture them discouraged.
• Tailgating: Tailgating occurs when an unauthorized person or
vehicle enters just behind an authorized person or vehicle
before the gate or door can close.

• Emergency access: In an emergency, the access
control system must allow emergency personnel or
vehicles access to secured locations. It must also
allow nonemergency personnel to evacuate without
getting in the way of the emergency response team.
Yet emergency access provisions must not provide an
attractive “exploit” that allows unauthorized persons
to defeat the system by staging a false emergency.

Tag and Ship
• Tag and ship applications are minimal RFID systems
that allow a user to associate an RFID tag with an item,
apply the physical tag to the item, and then verify that
the tag operates properly while attached to the item.
• In some cases, these systems even use pre-encoded
tags to further reduce cost.
Considerations
Cost: Because the drivers for this sort of application
typically comply with a mandate, keeping cost low is the
primary concern of the end user. This includes initial
cost and the total cost of ownership (TCO) over time,
from upgrades and repairs to monitoring and
maintenance.

• Isolation: Tag and ship systems are in some cases the first
automated system to be deployed at a given location. The
support and maintenance infrastructure needed for such
systems, and even the floor space they take up at the dock or
shipping area, often aren’t readily available.
• Tag failure: Manufacturing defect rates are still high for the
smart labels (paper tags with embedded RFID antennas and
chips) used in this type of application. Since the logistics of
trying to reorder missing numbers would be difficult, the
system may have to discard one or more labels before finding
a functioning label to apply to the item.

Pallet and Carton Tracking
• One of the most commonly mentioned forms of RFID,
pallet and carton tracking, essentially puts a “license
plate” on a shipping unit made up of one or more
individual items.
Considerations
• Pallet or carton integrity: This type of tracking works
best with a shrink-wrapped pallet that contains only
one type of item; the pallet ID is then associated with
a simple item count. It also works well with a mixed
pallet that has a more complex manifest, describing
counts for more than one item. Pallet and carton
tracking can be ineffective if there is a possibility that
the pallet or carton may be broken down and
reconstituted. In this case, the counts or manifest may
become invalid.

Pallet orientation:
Pallets have six sides.
Given that the bottom is typically inaccessible, we still
have five choices when deciding where to attach the tag.
Because most dock doors are roll-ups, placing a reader
overhead can be difficult, so few implementations tag
the top of the pallet.
Most pallets have an orientation, and shippers typically
place pallets with a certain side facing out, so in most
cases it isn’t necessary to put tags on all four sides.
Even if putting a tag on each side seems reasonable, this
means creating and reading a whole set of duplicate tags,
which can cause problems for both printers and readers.

Interfering contents:
• You might expect that a tag on the outside of a box would
be easily visible to a reader, regardless of its contents, but
this is not so.
• Imagine the reader as a bright light and the tag as a small
mirror.
• Could you see a small mirror attached to a larger mirror,
even if the light of a 300-watt floodlight illuminated it?
• A tag on a box of metal cans can be just as difficult for a
reader to distinguish.
• If the product contains metal, have mercy and put the tag
on a thin foam backing.
• The added distance will usually create enough space
between the tag and the reflected signal to greatly improve
read rates.

Track and Trace
• One of the earliest uses of RFID was to track dairy
cattle.
• Now, companion animals and livestock of all types
are routinely tagged with injectable glass capsules
or button ear tags.
• These tags are used to identify lost pets and to sort,
care for, and track the history of livestock.
• In recent years, RFID has also been increasingly
used to track produce and pharmaceuticals.
• Information from livestock, produce, or
pharmaceutical tracking can be critical in the event
of a public health threat.

Considerations
Information sharing:
• By definition, track and trace applications require information sharing.
• One of the key requirements when merging information is coordinated identification.
• If one producer claims this flat of strawberries should be called 12345 and another
claims that a different flat of strawberries should be called 12345, how can the
inconsistency be reconciled?
• What if one producer reuses numbers and sends a flat 12345 this week and another
flat 12345 next week?
• In any track and trace system, each identity must be unique across all producers and
for as long a period as the information must be maintained.
• This can be accomplished in several ways, but the simplest method is either to assign
a prefix to each producer to put at the beginning of their identities or to assign blocks
of identities to each producer from a central authority (which accomplishes the same
thing).
• Whatever method is used must be universally enforced otherwise, the integrity of
the data in the system will be suspect.

Role- and instance-based access control:
• Sharing information includes pooling information with
competitors.
• Track and trace systems must have a provision for role- and
instance-based control over access to information.
• In simplest terms, a role is a job, such as veterinarian or
retailer, while an instance is a particular person.
• For example, a retailer may need general information but
should not be able to view sensitive information about
individual producers or manufacturers.
• A veterinarian should be able to view detailed information,
but only for clients with whom she has a professional
relationship.
• A government inspector should be able to see which animals
or produce might have been commingled with a certain
suspect lot, but might not need to see any other information.

Smart Shelf
• A smart shelf system is a set of shelves, or some other
container (such as a refrigerator), that constantly keeps track
of the individual items it contains.
• If an item is removed or added, the shelf immediately updates
the inventory.
• By tying the identity of an item to its attributes, such as
expiration date or lot number, a system using smart shelves
can immediately locate all expired products and products from
a certain lot.
• An example of a smart shelf system is a system that contains
indicators such as horns or lights that warn users if a product
has been removed from refrigeration for too long and should
therefore be discarded.
• Similarly, if the user removes two drugs at the same time that
are known to interact negatively, the system signals a warning.

Considerations
Item-level inventory support:
• The most important consideration in a smart shelf
system is the necessity of resolving inconsistencies
between existing applications and a system that handles
individual inventory.
• Most inventory systems currently deal only with tuples
made up of stock keeping unit (SKU) codes and a count.
Physics and hardware:
• Developing a reliable smart shelf system from readers,
antennas, and standard shelving is a daunting task due to
the complexity of choosing components, placing
antennas, and modeling the possible side effects.

Handling spurious reads:
• A reader may sometimes fail to recognize a tag.
• This can be due to interference or absorption of the
RF signal.
• For instance, someone may reach for one item and
briefly block the signal response of several others.
• Also, passing carts full of items by the reader at
once may cause false positives to appear on a shelf.
• The systems must be able to deal with these reads in
a manageable way

RFID Architecture
• An architecture may be defined as a decomposition of a particular
computer system into individual components to show how the
components work together to meet the requirements for the entire
system.
• With this definition in mind, we can confidently say that there is no
such thing as a single, universal RFID architecture that fits all
requirements for all systems.
• Likewise, there is no set number of variations on a single theme.
• Because of a recent confluence of technologies, RFID systems now
offer some key functionalities that have a distinct and predictable
impact on the architectures of systems that use it.
• In this section, we describe the components that RFID adds to the
architectures of these systems and how RFID affects systemic
qualities (i.e., nonfunctional requirements of the system, such as
performance, security, scalability, and manageability).
• From these observations we will derive some architectural
guidelines for systems that incorporate RFID.

Confluence of Technologies
• RFID may be seen as the next logical step in the
progression of tracking systems and sensor networks
because of technological advances in several fields.
• Let’s look at some of the developments that have
made RFID possible.
1. Advances in semiconductor technologies
• RFID would have remained a niche technology if it
was not for Moore’s law and the ability of the
semiconductor industry to produce chips that
package processing power at a level that makes it
affordable for the mass RFID market.

2. Intelligent devices:
• Advances in semiconductor technologies haven’t just
brought down the cost of RFID chips—they are also the
primary drivers behind the development of intelligent
devices, including sensors such as RFID readers.
• Smarter devices and virtually ubiquitous bandwidth have
opened up a host of mobility and edge-based applications.
• RFID is one implementation of the general idea of a
“Network of Things” connected together to provide
automation beyond the edges of corporate data centers.
• Smart homes, smart cars, and other smart objects are
additional applications that require processing at the edges.
• Current implementations of smart home systems
incorporate a variety of IP-enabled household devices
connected to residential gateways that are in turn connected
to the Internet.

3. Broadband wired and wireless networks and
cheaper edge processing servers
• The availability of pervasive broadband data
networks, coupled with affordable yet powerful
servers, has led to the development of architectures
that move processing to where the business
processes are carried out.
• This means that it is now easier to deploy pieces of
enterprise applications in edge locations such as
warehouses and stores.

4. Edge processing capability
• Edge processing capability derives from having
powerful yet low-cost personal computers and servers
deployed at the edges of the enterprise network as
well as a broadband connection to the data center.
• RFID systems put greater computing, data
management, and bandwidth requirements on these
edges.
• This is not a unique phenomenon, however, but a
continuation of the overall trend.
• By “edge,” we mean any location where business
processes are carried out that is outside the data
center or central office (for example, on production
lines, in warehouses, or at retail locations).

5. Service-oriented architecture
• Successful adoption of RFID technologies in your enterprise will
depend on how well you integrate the RFID data into your
business processes.
• RFID readers can generate a lot of data.
• If it is exposed unfiltered to downstream applications, it can
overwhelm them.
• To prevent applications from being flooded with RFID data and to
isolate them from physical devices such as readers and antennas,
you can use sophisticated middleware components such as event
managers.
• Service-oriented architectures allow us to develop and deploy
loosely-coupled modules that interface with each other using web
services–based standards.
• Many of the RFID middleware components are based on web
services standards, and the overall RFID system architecture
follows the principles widely accepted today as the underpinnings
of service- oriented architectures.

Key Functionalities
• There are many possible uses for RFID systems, there will naturally be
differences in their architectures.
• A typical tag and ship application implemented by a consumer packaged
goods manufacturer would focus primarily on automating RFID tagging of
products and ensuring that the tags can be read by the specified readers at
higher than the minimum acceptable read accuracy.
• Generally speaking, these systems focus on the physical side of the
implementation, and outside of generating fairly simple reports such as
advanced shipment notifications (ASNs), they tend to have minimal data
management/exchange requirements.
• On the other hand, a pharmaceutical company that wants to track the
movement of drugs from manufacturing plants to distributors to retail
pharmacies would want up-to-the-minute information, including details on
where a particular product is at any point in the process, how and where it was
manufactured, and where it has been.
• It is very likely that both the manufacturer and the retailers will also need
some of this tracking information.
• Thus, such a system will require not only item-level tracking capabilities, but
also some degree of business-to-business (B2B) information exchange.

RFID system must provide the following features and
capabilities :
• The ability to encode RFID tags
• The ability to attach encoded RFID tags to items
• The ability to track the movement of tagged items
• The ability to integrate RFID information into
business applications
• The ability to produce information that can be
shared between businesses
• The ability to develop self-organization of
intelligent devices

Encoding RFID:
• Tags Encoding RFID tags is a two-step process.
• The first step is to select an identification scheme to
uniquely track the items in question.
• Once this is done, you can attach those identities to
the RFID tags.
Deciding on an item-numbering scheme:
• Identification is the act of recognizing the identity
of an object or item.
• In RFID, an identity is a string of letters and
numbers attached to an item to allow a person or an
automated system to recognize either that item’s
type or even the unique item itself.

Tags
• The term “RFID” is typically used to describe systems
wherein a base station of some sort (a reader) is able to
recognize another electronic device (a tag) using one of
several possible wireless transmission mechanisms.
• These mechanisms may include microwave but not
infrared or visible light systems.
• Since a reader is able to identify a particular tag, the
system can claim to have identified the object to which
that tag is attached.
• Tags may be housed in small plastic buttons, glass
capsules, paper labels, or even metal boxes.
• They may be glued to a package, embedded in a person
or an animal, clamped to a garment, or hidden in the
head of a key.

Important characteristics of RFID tags include the
following:
Packaging
• The DIN/ISO 69873 standard defines a standard for
tags that may be inserted into holes built into
machining tools.
• Some tags used in auto assembly lines are designed
and packaged to survive the intense heat of paint-
drying chambers.
• In short, the ways in which tags can be packaged are
remarkably varied.

Coupling:
• Coupling refers to the means by which the reader
and tag communicate.
• Different coupling methods allow for different
strengths and weaknesses.
• Coupling choices especially affect the range of
communications, the price of tags, and the
conditions that might cause interference.

Power:
• Many RFID tags use some sort of “passive” system,
wherein an electromagnetic field or a pulse of radio
frequency energy emitted by the reader powers the
tag.
• In other (“active”) tags, a battery powers a microchip
or additional sensors.
• However, active tags still use power from the reader
for communications.
• The third type of tag is the so called “two-way tag,”
which powers its own communications and may even
be capable of communicating directly with other tags
without a reader.

Information storage capacity
• Tags provide varying amounts of storage capacity.
• Read-only tags are set to store a particular value at the
factory.
• Users can set a value to write once tags one time, while
the value stored by a write-many tag may be changed
many times.
• Some tags are also able to gather new information, such
as temperature or pressure readings, on their own.
• Tags range in storage capacity from the 1-bit tags used
for theft prevention to tags used in auto assembly lines,
which may store thousands of bytes.

Standards compliance:
• Many types of RFID systems conform to particular
national and international standards.
• A developer working on “an ISO 11785 system” is
actually working on a system compatible with that
standard.
• Some standards, such as the Class system used by
EPCglobal, specify frequencies, coupling type,
information storage capacity, and more.

Selecting tags:
Many considerations are involved in selecting tags.
They include the following:
Required read range
Material and packaging
Form factors
Standards compliance
Cost

Readers
• RFID readers, also called interrogators, are used to recognize
the presence of nearby RFID tags.
• An RFID reader transmits RF energy through one or more
antennas.
• An antenna in a nearby tag picks up this energy, and the tag
then converts it into electrical energy via induction.
• This electrical energy is sufficient to power the semiconductor
chip attached to the tag antenna, which stores the tag’s identity.
• The tag then sends the identity back to the reader by raising and
lowering the resistance of the antenna in a kind of Morse code.
• This is only one scenario, and different tags can work in slightly
different ways, but this is typical of the way readers and tags
interact.
• Readers come in many shapes and sizes and can be found in
stationary, as well as portable, handheld varieties.

RFID Middleware
• Choosing the right tags and readers and determining where to
put the antennas is only the first step in building a working
RFID system, because identifying items is only the first step in
managing them.
• The capability to read millions of tags as they move through the
supply chain and the need to tie tag codes to meaningful
information will generate large amounts of data with complex
interrelationships.
• One of the primary benefits of using RFID middleware is that it
standardizes ways of dealing with the flood of information these
tiny tags produce.
• In addition to event filtering, you also need a mechanism to
encapsulate the applications so as to prevent them from knowing
the details of the physical infrastructure (readers, sensors, and
their configurations).

RFID Service Bus
• An enterprise service bus (ESB) is a distributed
integration platform designed for application
connectivity, data transformation, guaranteed
transactions, and messaging.
• An RFID service bus is a type of ESB used to
integrate applications using RFID data.
• Depending on the implementation you choose, ESB
products offer web services, messaging, business
process orchestration, and other capabilities.
• Generally, ESBs orchestrate business processes
across application, or sometimes enterprise,
boundaries.

RFID information service
• It is important to realize that an EPC, or for that matter,
any other item identification system, is just a unique
identifier and by itself does not provide any product
details.
• EPCglobal envisions that collaborating businesses and
industries will set up a network of EPC Information
Service (EPCIS) servers to provide an on-demand
repository of information related to individual EPCs.
• Information made available using the EPCIS servers
could include the last observed location of an item
carrying an EPC (based on an RF reader observation), as
well as pricing information and product manuals, if
appropriate.

RFID information network
• As RFID-tagged products move through the supply chain, various
participants in the supply chain will need standards-based means to
share their tracking information and to get reference information on
products based on their product tags (EPCs).
• EPCglobal envisions a mesh of networked B2B EPCIS systems
collaborating to provide a comprehensive reference source for EPCs.
• The EPCglobal Network is a vision coupled with an evolving set of
standards that aims to provide a standard framework for product
information exchange.
• Centered around EPC RFID technologies and the existing Internet
infrastructure, the EPCglobal Network will offer the potential for
increased efficiency and accuracy in tracking products between
trading partners.

System Quality Considerations
• A system’s requirements come in two flavors:
1. Functional
2. Nonfunctional
• The functional requirements define what the system
does, while nonfunctional requirements involve
systemic qualities such as privacy and security,
performance, scalability, manageability,
extensibility, and maintainability.
• RFID systems demand vastly increased data-
processing capabilities at the edges of corporate
environments.

• Some of the most important systemic qualities for
RFID systems are
1. Privacy and Security
2. Performance
3. Scalability
4. Manageability
5. Extensibility and Maintainability

Privacy and Security
• In any enterprise system, security considerations
for an RFID system—ensuring the authenticity
of the information stored on the tags themselves,
securing the transmission of information
between tags and readers, and ensuring overall
application and infrastructure security—
permeate the various layers of its architecture.

Performance
• Performance is measured in terms of time taken to
perform a unit of activity.
• Depending on the layer of the RFID system at
which you’re working, the performance
considerations will vary.
• For instance, for the physical layer, the time
required to recognize a tag is an important
performance consideration.

Scalability
• Scalability has to do with how small a system may
start and how quickly it must be ready to grow.
• For RFID systems, scalability involves much more
than “CPU headroom.”
• RFID scalability requirements are often stated like
so: “The shipping system should be able to handle
12 loading docks initially and be able to scale to 60
loading docks in 3 years with no more than a 2-
week cycle to install a group of 4 new loading
docks and bring them online.”

Manageability
• RFID information servers are typically housed in a
data center or server room.
• Operations staff can monitor and manage the
servers using procedures developed for any other
application server.
• Event managers and readers are found in loading
bays and warehouses, in truck trailers and train
yards, and even in corrugated tin shacks in the
middle of fields.
• A reader may be just as complex as a server,
requiring software or firmware upgrades,
monitoring, and management.

Extensibility and Maintainability
• . An RFID installation of any size must be prepared
to plug in readers with different mounting
requirements, different management interfaces, and
even different manufacturers depending on what is
available this week.
• Requirements in this area are often stated thus: “The
receiving system should be able to use any EPC
Class I reader from any vendor, with less than three
person- days of configuration for a new type.”

Architecture Guidelines
• The infrastructure for RFID edge components must
be incredibly robust. Ideally, the readers, RFID
middleware, and so on should support effortless
plug- and-play functioning.
• In other words, they should be the edge equivalents
of telephones in terms of ease of use, provisioning,
monitoring, and management.
• A human operating a bar code scanner will be able
to tell if the scanner goes down, but you’ll need to
employ automated means to monitor and manage
RFID readers.
.

• To support all this, your edge architectures will need
to be more flexible, scalable, robust, secure, and
manageable than ever before.
• As is always the case in a technology’s early
adoption phase, RFID standards and products are
rapidly evolving.
• RFID systems are no different than any other
distributed system in that you should plan for
performance, scalability, security, manageability,
maintainability, ease of use, and failover early on.

Important principles to consider when
devising an RFID architecture roadmap
for your company
Begin with Business Requirements
Don’t Forget Your Existing
Infrastructure
Process Data at the Edge Where
Possible
Track Items to the Level Your Business
Processes Will Support

System Management
• The level and scale of automation for some RFID
systems poses significant challenges for system
administrators and managers.
• The automated processing capabilities that RFID
technologies offer make automated detection of system
faults and stoppages indispensable.
• Similarly, we need to provide novel solutions for
provisioning, monitoring, and managing our silently
ticking antennas, readers, and other RFID infrastructure
components.
• Think ease of configuring, provisioning, managing, and
monitoring when deciding on infrastructure components
such as readers, sensors, event managers, servers,
storage, and networks.

• Build redundancy into the architecture. Have a plan
in place for what should happen when an antenna, a
reader, or an event manager malfunctions
Start with Architecture
Use RFID Middleware

UNIT- II
TAGS AND PROTOCOLS
Basic tag capabilities - physical characteristics - power source - air interface
–information storage and processing capacity- standards protocol terms and
concepts- how tags store data-singulation and anti-collision procedures-tag
features for security and privacy- learn to
troubleshoot tag communications

Basic Tag Capabilities
The purpose of an RFID tag is to physically attach
data about an object (item) to that item.
 Each tag has some internal mechanism for storing
data and a way of communicating that data.
Not every sort of RFID tag has a microchip or a built-
in power source, but every RFID tag has a coil or
antenna of some sort.
All tags have in common, but classification helps in
understanding how they work.

Many basic operations can be performed with an
RFID tag, but only two of them are universal.
The operations are
 Attaching the tag
 Reading the tag
 Kill/disable
 Write once
 Write many
 Anti-collision
 Security and encryption
 Standards compliance

Physical Characteristics
RFID tags must physically attach data to items of different
shapes and sizes in different environments.
Some of the physical characteristics of various tags include:
 PVC or plastic buttons and disks central hole for
fasteners(durable and reusable)
 RFID tags shaped like credit cards, which are called
“contactless smart cards.”
 Tags made into the layers of paper called “smart
labels.” similar to bar code labels.
 Small tags embedded in common objects such as
clothing, watches, and bracelets. These small tags may
also come in the form of keys and key chains.
 Tags in glass capsules, which can survive even in
corrosive environments or in liquids..

Power Source
Tag can be categorized by their source of
power. It also determines the factors for the cost
and longevity of a tag.
Passive tags obtain all of their energy by some
method of transmission from the reader.
Active tags use an on-board battery to power
communications, a processor, memory, and
possibly sensors.
Traditionally, tags that use battery power for
some functions but still allow the reader to
power communications have been termed
“active” as well, but for clarity, we will use the
more recent terminology for them: semi-passive.


One additional type of tag  not only capable of
supplying power for itself but is also able to
initiate communications with other tags of its own
kind without the aid of a reader. These tags are
called two-way tags.

An active tag may have an extremely long read
range and may perform some functions in the
absence of a reader
EX., Battery power for environmental sensors.
This capability can be very useful for tags that
identify items such as perishable goods.

Air Interface
The air interface describes the way in
which a tag communicates with a reader.
Tag’s air interface determine the tag’s
read range and identify readers
compatible with the tag.
The major attributes include the tag’s
power source, operating frequency,
communication mode, keying,
encoding, and coupling.

Operating Frequency
The operating frequency is the
electromagnetic frequency the tag uses
to communicate or to obtain power.
The electromagnetic spectrum in the
range in which RFID typically operates
into low frequency (LF), high frequency
(HF), ultra-high frequency (UHF), and
microwave

Different frequencies have different
properties.
 Lower frequency  better able to travel
through water,
 Higher frequency  carry more information
& easier to read at a distance
Read range by frequency

Communications Mode
The tag and the reader can “talk” at the same time.
This is known as the communications mode.
As with wired communications, RF communications
may be full-duplex (FDX) or half-duplex (HDX)—
that is, the tag and reader may talk at the same time
(FDX) or take turns (HDX).
In most cases, for passive tags, the reader provides
power throughout the conversation, but in one
variation on HDX, power transmission stops while
the tag responds.
A capacitor or some physical property of the tag
allows it to store energy and respond while the power
transmission is off. This communications mode is
called as sequential (SEQ).

Types of Keying
The term “keying” comes from the days of telegraphy,
when an operator pressed a manual key to make long and
short tones.
Keying describes which attributes of an analog carrier. The
analog carrier can be a wave or a field may be modulated to
represent the ones and zeros of a digital message.
There are three main types of keying:
• Amplitude-shift keying (ASK)- sends digital data
over analog carriers by changing the amplitude of a
wave in time with the data stream
• Frequency-shift keying (FSK)- sends changes
through the frequency of the wave (or how often a
wave crest comes along)
• Phase-shift keying (PSK)- sends changes through the
distance by which the waves lead or follow a reference
point in time

Encoding
Encoding determines the way the tag and
reader will interpret changes in the analog
carrier to represent digital data.
Morse Code, one example of an
encoding, uses long tones to represent
“dashes” and short tones to represent
“dots.” If we substituted “0” for “dash” and
“1” for “dot,” Morse encoding would work
for sending information over a serial bus.

Various encoding schemes commonly used in
RFID include:
•Biphase Manchester encoding
•Pulse interval encoding
•Biphase space encoding
•Pulsed RZ encoding
•EPC Miller encoding
•“1 of 256” and “1 of 4”
•FSK subcarrier encoding

Biphase Manchester encoding
This encoding uses a negative transition in the
middle of the bit cell to mean a “1” value and a
positive transition in the middle of the bit cell to
mean a “0” value.
Transitions that happen at the bit cell boundary do
not encode a value and are used to “reset” the
encoding to send the same value again in the middle
of the cell

Pulse interval encoding
This is similar to Morse Code, where values are
encoded by the length of the pause, or interval
between, short pulses. A pause of a specific length
represents a “1,” while a pause twice as long
represents a “0.”
 Advantages - requiring less power and being
resistant to noise.
It may be a problem for longer transmissions,
though, because the data stream does not contain a
clock.

Biphase space encoding
In biphase space encoding a type of
encoding that is often used for reader-
to-tag communication transitions
happen at each clock tick.

Pulsed RZ encoding
•The “RZ” means “return to zero,” which is a
term used to describe encodings in which the
signal returns to a point that is neither high
nor low (i.e., at zero) for some part of the bit
cell
EPC Miller encoding
•Miller encoding encodes a number by having
a transition in either direction at the half bit
point

“1 of 256” and “1 of 4”
• These two forms of encoding are used in tags that
conform to ISO 15693.
 For “1 of 256,” values from 0 to 255 may be
encoded in the data stream by the timing of a pulse.
There are 512 timing slots per frame during which a
pulse may occur, and the value is encoded by
multiplying it by 2 and then adding 1.

FSK subcarrier encoding
This sort of encoding is the exception to our earlier
claim that RFID communicates over a serial bus and
that encoding and keying are different.
In this type of encoding, two subcarriers represent
“1” and “0,” respectively, and the sender uses FSK
to create pulses on these subcarriers in time with the
data stream.
EPC UHF tags use FSK subcarrier encoding to talk
to a reader.

Coupling
• A tag’s coupling mechanism determines the way a
circuit on the tag and reader influence each other
to send and receive information or power.
• The type of coupling a tag uses directly affects
the read range between the tag and reader.
• We can group the different read ranges loosely
into those systems where the read range is close
(within 1 cm), remote (1 cm to 1 m), or long-
range (more than 1m). A synonym for remote
coupling is “vicinity coupling.”

Types of Coupling
Backscatter coupling
Inductive coupling
Magnetic coupling
Capacitive coupling
• Capacitive and magnetic coupling are examples
of close coupling,
• inductive coupling is a type of remote coupling,
and
• backscatter coupling may be remote to long-
range.

Backscatter coupling
Backscatter coupling provides an elegant solution
to the puzzle of how to make an RFID tag without a
battery. The name itself, “backscatter,” describes the
way the RF waves transmitted by the reader are
scattered back by the tag.
 The waves are reflected back to the source to send
a signal.
Imagine the reader as a flashlight and the tag as a
signaling mirror with a cover,

Backscattering an RF signal is like
reflecting light with a signaling mirror

Inductive coupling
• Inductive coupling is a common type of remote
coupling
• The field drives current through a coil on the tag
by induction in much the same way that a
transformer transfers energy between two coils.
• For this reason, this type of coupling is sometimes
called transformer coupling

Magnetic coupling
• Magnetic coupling is a close coupling that is
similar to inductive coupling in that the
reader and tag form a pair of transformer
coils.
• The major difference is that the reader coil in
magnetic coupling is a round or u-shaped
ferrite core with windings,

Capacitive coupling
• Capacitive coupling dispenses with antennas and
replaces them with electrodes. The reader and tag
each have conductive patches that together form a
capacitor when held exactly parallel to each other
without touching.
• As with magnetic coupling, this type of coupling
can easily power complex tags, and it may use
simple ASK with load modulation to transfer data.

Information Storage and
Processing Capacity
Information storage and processing capacity is the
final major consideration when dividing tags into
categories.
 RFID tags range widely in their capability to store
information.
This section examines storage and processing
capacities for
• 1-bit EAS tags,
•surface acoustic wave (SAW) tags, and
•state machines and microprocessors.

One-Bit EAS Tags
Electronic Article Surveillance (EAS) tags are typically used to
prevent theft. Rented videos and library books typically have
EAS tags attached in the form of thin strips or labels.
Stores often tag clothing with EAS tags inside hard plastic clips
or buttons that are difficult to remove without the correct tool.
Some EAS tags are even designed to damage an item if
removed incorrectly and so discourage theft.
EAS tags are often called “1-bit” tags because they are capable
of communicating 1 bit of information. One bit may be used to
store the answer to a yes or no question— in this case, the
question is, “Is there a tag present?” If a tag is detected, the
answer is “1” or “yes.” If a tag is not present, the answer is “0”
or “no.” EAS tags are simple and inexpensive. At present, these
are the most commonly used RFID tags.
The types of coupling available in EAS tags are as numerous as
in other types of RFID tags—for example, EAS tags may use
induction or backscatter coupling, as do the more complex tags.

Surface Acoustic Wave (SAW) Tags
• In between the 1-bit tags and other, more advanced
RFID tags is an ingeniously designed oddity.
• SAW tags operate in the microwave range as
backscatter tags and have no processors, but unlike
1-bit tags, a SAW tag can be encoded at the point of
manufacture to contain a number

•The antenna at the left receives the
microwave pulse from the reader and
feeds it to the inter digital transducer
(the block on the left). The transducer
contains a piezoelectric crystal, which
vibrates when it receives the microwave
pulse.
•This vibration creates an acoustic wave
that travels through the tag,
encountering reflector strips (shown on
the right).

State Machines and Microprocessors
• Some tags have more complex logic circuits
than others. Most 1-bit tags and all SAW tags
have no logic circuits at all, while other types
of tags have sophisticated state machines
incorporated into custom chips.
• Some tags have more complex logic circuits
than others. Most 1-bit tags and all SAW tags
have no logic circuits at all, while other types
of tags have sophisticated state machines
incorporated into custom chips

Standards
• Some RFID applications need to interoperate
only with the procedures and systems of a single
company. Others must share information with a
global consortium of partners
• Choosing a tag is, to a large extent, choosing the
type of RFID system you intend to build, and tag
standards often involve much more than the
physical characteristics and air interface of a tag.
EPCglobal Tag Types
IS0/IEC 18000 Tags
IS0 15693 Vicinity Smart Cards

EPCglobal Tag Types
• EPCglobal, Inc., a collaboration between GS1
and industry partners, defines a combined
method of classifying tags that specifies
frequencies, coupling methods, types of keying
and modulation, information storage capacity,
and modes of interoperability.
• EPC tags are intended to carry EPC numbers,
which are assigned by the specific management
entities who own the object classes involved.

The different classifications of tags recognized by
ECPglobal.

• These classifications, which began with the Auto-ID Center,
have mutated as actual standards developed and vendors made
suggestions
• ECPglobal has consistently promised to provide a reasonable
migration path for early adopters. The standard defines an air
interface from 860–930 MHz in the UHF range.
• Earlier Auto-ID Center working documents also defined an air
interface for 13.56 MHz in the HF range.
• EPC HF tags are inductive coupled FDX tags with read ranges
of up to one meter. These tags use a protocol called the Slotted
Terminal Adaptive Collection (STAC) protocol, which allows a
reader to select a single tag from among a group of tags. For
this reason, this protocol is called a singulation protocol.

• EPC UHF Gen2 tags use backscatter coupling and
an HDX communication mode, allowing for read
ranges of up to 10 meters with optimal orientation
of the tag and reader.
• Reader to- tag communications are ASK and pulse
interval encoded, and tag- to-reader
communications are encoded using FSK
subcarriers with biphase space or Miller encoding.
• These tags use a different singulation protocol
than the HF tags, the Slotted Random Anti-
Collision (SRAC) protocol takes advantage of the
faster turnaround time in UHF communications.
• Earlier EPC UHF tags used still another protocol,
known as Adaptive Binary Tree (ABT).

IS0/IEC 18000 Tags
• In the past, GS1 has backed both the EPC standards
and the GTAG initiative, which includes the 18000-6
standard for UHF.
• This standard originally conflicted with the EPC
UHF specification and the new EPC UHF Generation
2 specification, but tag manufacturers were already
selling EPC Class 0, Class 0+, and Class I tags.
• Some have expressed concern that the 18000 air
interfaces and command protocols are more complex
than those defined by the EPC standards, which
could lead to both more expensive tags and stall
adoption of the standard.

IS0 15693 Vicinity Smart Cards
• The ISO 15693 standard was originally intended as
a specification for “vicinity cards.” These
contactless smart cards are typically used for access
control but have also been used for many other
applications, including supply chain and asset
tracking.
• This standard defines one type of tag, which should
be the size and shape of a credit card, inductively
coupled, using ASK from reader to tag and ASK or
FSK from tag to reader. ISO 15693 also defines an
anti-collision procedure called the Slot Marker
Method and two encoding methods.
• The method intended for fast reads is called “1 of
4,” and the method intended for long range is called
“1 of 256.”

Protocol Terms and Concepts
• A protocol is defined as A set of formal rules describing
how to transmit data, especially across a network.
• Low level protocols define the electrical and physical
standards to be observed, bit- and byte ordering, and
the transmission and error detection and correction of
the bit stream.
• High level protocols deal with the data formatting,
including the syntax of messages, the terminal to
computer dialogue, character sets, sequencing of
messages, etc.
• Technical jargon develops around any new technology,
and RFID is no exception. Some of these terms are
quite useful, serving as a convenient way to
communicate concepts.

Singulation
Anti-collision
Identity
• Singulation-This term describes a procedure for
reducing a group of things to a stream of things that
can be handled one at a time. For example, a subway
turnstile
• Anti-collision-This term describes the set of
procedures that prevent tags from interrupting each
other and talking out of turn. Whereas singulation is
about identifying individual tags, anti-collision is about
both regulating the timing of responses and finding
ways of randomizing those responses so that a reader
can understand each tag amidst the plethora of
responses.

Identity
• An identity is a name, number, or address
that uniquely refers to a thing or place.
“Malaclypse the Elder” is an identity
referring to a particular person. “221b Baker
Street London NW1 6XE, Great Britain” is
an identityreferring to a particular place, just
as “urn:epc:id:sgtin:00012345.054322.4208”
is an identity referring to a particular widget.

How Tags Store Data
• The high-level tag communications protocols know
about the ID types that can be stored on a tag.
• The CRC-Cyclic Redundancy Check is a
checksum (described in more detail in the sidebar
“CCITT-CRC”), the EPC is the ID on the tag, and
the password is the “kill code” to disable the tag.
• The standard defines one encoding for General
Identifiers (GIDs), which is intended for creating
new identification schemes, and five specific
encodings—called System Identifiers—for
particular uses. The System Identifiers are based on
existing GS1 (EAN.UCC) identifiers.

CCITT-CRC
• A Cyclic Redundancy Check (CRC) is a way of
verifying that a block of data is not corrupted.
• The sender of the data block calculates a value by
treating the whole block as one large number and
dividing it by a number called the CRC polynomial.
• The remainder of this operation is the CRC. The
sender sends this CRC along with the data, and the
recipient uses the same method to calculate a CRC
over the data block for comparison.

GS1 SGTIN Encoding
• EPC readers and RFID middleware present tag data
according to its EPC encoding.
• The SGTIN is a good example of an identity and its
encoding
• EPC-SGTIN is an extension of the GS1 GTIN that
assigns Company Prefixes and Item References for
use in identifying particular classes of object. The
common digit UPC and digit EAN bar codes are a
subset of the GTIN. These types of codes are being
merged with the 14-digit GTIN in 2005 by
prepending zeros to the existing codes.

• Figure  shows a typical UPC bar code.
• To convert this UPC into an EPC and store it on an
RFID tag, we must first convert it to a GTIN.
• This bar code has an Indicator Digit (0), a
Company Prefix (12345), an Item Reference
(54322), and a check digit (7).
• To convert this to a GTIN, we take the entire code
as a string and add two zeros to the beginning,
yielding a GTIN of 00012345543227.
• Notice that our Company Prefix has now become
00012345, an 8-digit number. We will then convert
the GTIN to an SGTIN—which allows us to track
individual items—by adding a Serial Number
(4208).

• For an SGTIN, this notation is:
• urn:epc:id:sgtin:CompanyPrefix.ItemReference.Ser
ialNumber
• urn:epc:id:sgtin:00012345.054322.4208

• The steps to encoding a 96-bit EPC to a binary string
are:
• Find the appropriate header for the identity type.
• Look up the partition value based on the length of the
Company Prefix.
• Concatenate the 8-bit header, 3-bit filter, and 3-bit
partition fields.
• Append to this the Company Prefix and other fields
appropriate to the identity (Item Reference and Serial
Number for an SGTIN).
• Calculate the CRC and append the EPC to the end of
the CRC.

Singulation and Anti-Collision
Procedures
• There are many different ways for readers
and tags to communicate, but the different
methods can all be broadly categorized as
Tag Talks First (TTF) or Reader Talks First
(RTF).
• the most common of these protocols for
RFID—Slotted Aloha, Adaptive Binary Tree,
Slotted Terminal Adaptive Collection, and
the new EPC Gen2 specification

Slotted Aloha
• Slotted Aloha is derived from a procedure known simply as
“Aloha,” which was originally developed in the 1970s by Norman
Abramson of Aloha Networks in Hawaii for packet radio
communication. Aloha was the inspiration for the Ethernet
protocol, and a variation of this procedure is still used for satellite
communication as well as for ISO 18000-6 Type B and EPC Gen2
RFID tags.
• Slotted Aloha uses three commands to sort out tags:
REQUEST
SELECT
READ

Adaptive Binary Tree
• EPC Class 0 and Class I Version 1.0 (Generation 1)
UHF tags use a slightly more complicated
• approach to singulation and anti-collision known as
an Adaptive Binary Tree procedure.
• The EPC specification for the air interface of UHF
tags uses two separate subcarriers for 1s and 0s in
tag responses.

The Adaptive Binary Tree protocol states:
• Global states
Dormant-initial state a tag & after it has been
read.
Global Command Start-state and waits for a 1
or a 0 from the reader
Global Command-the tag is ready to receive
and process commands that affect all tags or
groups of tags that have not been singulated
Singulated Command Mute-a tag waits quietly
until it receives a data null

Slotted Terminal Adaptive Collection (STAC)
• STAC is defined as part of the EPC
specification for HF tags. Because it defines
up to 512 slots of varying lengths, it is
especially well suited to singulation of large
populations of tags
• Because the EPC code is organized by
Header, Domain Manager Number, Object
Class, and Serial Number (in that order) from
MSB to LSB, this mechanism can easily
select only tags belonging to a particular
Domain Manager or Object Class.

STAC slots
STAC protocol state diagram

EPC UHF Class I Gen2
• The latest revision of the EPC UHF Class I
air interface is called the “Gen2 protocol.”
• The EPC Gen2 protocol supports much faster
tag singulation than the previous protocol,
with tag reads rates as fast as 1,600 tags per
minute in North America and 600 tags per
minute under the more constrained power
and frequency ranges in Europe.
• One of the primary concerns it addresses is
added security for the protocol.

• A reader may also access tags, which
includes reading information from a tag,
writing information to a tag, killing a tag, or
setting the lock status for various sections of
tag memory by memory bank number.
• Tag memory
• The Gen2 protocol recognizes an optional
user memory area and a Tag Identifier (TID)
in addition to the CRC+EPC, which is called
an Object Identifier (OID) in the
specification

Tag memory banks
.
The inventory commands are:
 Query
 Query Adjust
 QueryRe
 ACK
 The Select command
 Access commands

Tag Features for Security and
Privacy
• A common concern is that an unauthorized
person will be able to obtain information
from, or possibly even change information
stored on, an RFID tag.
Destroying and Disabling Tags

Learn to Troubleshoot Tag
Communications
•Troubleshooting tag and reader
communications is the sort of subject
that could (and probably someday will)
fill up, but a few general techniques can
solve the most common problems.
•Not many of us have spectrum
analyzers, but RF questions can usually
be approached indirectly.

20EC7020E -RFID AND FLEXIBLE SENSORS
UNIT- III
READERS, PRINTERS AND READER
PROTOCOLS
Physical and logical components of RFID reader -
parts of RFID printer and applicator - types of
readers- layout for readers and antennas
configuring readers parts of a reader protocol -
vendor protocols - EPC global protocol overview -
simple lightweight RFID reader protocol -future
protocols.

Physical Components of an
RFID Reader
• The reader communicates with tags using RF, any
RFID reader must have one or more antennas.
Because a reader must communicate with some other
device or server, the reader must also have a network
interface of some sort.
• Examples of common network interfaces are the serial
Universal Asynchronous Receiver/Transmitters
(UARTs) for RS 232 or RS 485 communications and
the RJ45 jack for 10BaseT or 100BaseT Ethernet
cables, some readers even have Bluetooth or wireless
Ethernet communications built in.

• To implement the communications protocols and
control the transmitter, each reader must have either a
microcontroller or a microcomputer.
The physical components of an RFID reader.

Antenna Subsystem
Although the antennas themselves are
simple in concept, engineers work
constantly to get better reception at lower
power and to adapt the antennas to
special circumstances.
Some readers have only one or two
antennas, packaged with the readers
themselves; other readers may be able to
manage many antennas at remote locations.

 The primary limitation on the number of antennas is a
reader can control the signal loss on the cable
connecting the transmitter and receiver in the reader
to the antennas.
 Most installations keep the reader within about six
feet (two meters) of the most distant antenna, but
much longer runs are possible.
 Some readers use one antenna to transmit and one to
receive. If the transmitting antenna is “ahead” of the
receiving antenna, the receiving antenna will have a
longer amount of time to receive signals from the tag.
 If the antennas are reversed, the tag will spend much
less time energized and within range of the receiving
antenna.

Preferred placement of receiving
and transmitting antennas

Controller
• The computing device that controls a reader can vary in complexity
from a simple state machine on a chip, which might be used for a
tiny embedded reader on a telephone or PDA, to a complete
• microcomputer system capable of running a server operating system
as well as end user applications and accumulating a large amount of
data on an internal hard disk.
• The controller is responsible for controlling the reader side of the
tag protocol as well as determining when information read from a
tag constitutes an event to send to the network.
• The reader controller is also responsible for managing the reader’s
end of the reader protocol.

Network Interface
• Reading tags and recognizing events wouldn’t be much
use if the reader never told anyone about those events.
Readers communicate with the network and other
devices through a variety of interfaces.
• Historically, most RFID readers have serial interfaces
using RS 232 or RS 422 (point to point, twisted pair) or
RS 485 (addressable, twisted pair).
• In recent years, more and more readers have supported
Ethernet; some
• have begun to support built-in wireless Ethernet,
Bluetooth, and even ZigBee.

Logical Components of an Rfid
Reader

Reader API
• Each reader presents an application programming
interface (API) that allows other applications to
request tag inventories, monitor the health of the
reader, or control configuration settings such as
power levels and the current time.
• This component is mostly concerned with creating
messages to send to the RFID middleware and
parsing any messages received from the
middleware.
• The API may be synchronous or asynchronous.

Communications
• The communications subsystem handles the details
of communicating over whatever transport protocol
the reader may use to communicate with the
middleware.
• This is the component that implements Bluetooth,
Ethernet, or a proprietary protocol for sending and
receiving the messages that make up the API.

Event Management
• When a reader “sees” a tag, we call this an “observation.”
An observation that differs from previous observations is
called an “event.”
• Separating out these events is called “event filtering.”
• The event management subsystem defines what kinds of
observations are considered events and which events are
considered interesting enough to put in a report or send
immediately to an external application on the network.
• As readers become smarter, they will be able to apply
more complex processing at this level to reduce network
traffic.
• Essentially, some parts of the event manager component of
the middleware will naturally migrate to merge with the
event management component of the reader.

Antenna Subsystem
• The antenna subsystem consists of the interfaces
and logic that enable the RFID readers to
interrogate the RFID tags and control the physical
antennas.

Parts of an Rfid Printer and Applicator
• Many of the most commonly used tags for Compliance-era
applications are smart labels. RFID tags embedded in adhesive
paper labels.
• The primary advantage of this sort of tag is that the user, in addition
to encoding the RFID tag with an identity, can print a bar code
and/or human-readable text onto the paper label before attaching it
to an item.
• RFID printers are devices that both encode tags and print to the
paper labels that house the tags. Remember that a reader can also
“write” to a tag that allows writes, so the primary difference
between an RFID reader and an RFID printer has nothing to do with
the capability to encode tags; the difference has only to do with the
laser or inkjet printer component of the RFID printer.

Parts of a print-and-apply device

Types of Readers
• Readers, like tags, differ in many ways, and no one
reader is a perfect fit for all occasions.
• Readers come in many shapes and sizes, support
different protocols, and often must conform to
regulatory requirements, which means that a
particular reader may be acceptable for an
application in one region of
the globe but not in another.

Shapes and Sizes
• Readers range in size from half an inch (two
centimetres) across to the size of an old desktop
computer.
• Readers may be embedded in handheld devices or
even cell phones. They may be fixed to the wall
in an explosion-proof housing.
• Readers may even be built into shelving units and
doorways along with antennas for smart shelf and
portal applications.

Standards and Protocols
• Readers conform to the same standards and
protocols as the tags they read, but some readers can
support multiple tag protocols.
• Some readers are proprietary and support only tags
made by a particular vendor.

Regional Differences
• Permissible power levels, frequency variations, and
regulatory requirements vary from region to region, even
when applied to the same type of tag.
• For example, EPC UHF readers read the same tags at 915
MHz in the U.S. and at 869 MHz (and lower power) in
Europe due to regulatory constraints.
• EPC global, ISO, and other standards organizations are
working to come up with standards that will be able to
operate globally, but for now, readers must be selected
carefully to ensure that they comply with local regulations.
• For more information, consult the manual for a specific
reader.
• It will list the regions within which the reader is certified to
operate.

Layout For Readers And Antennas
• A reader and its antennas must be installed to be of
any use. Since with RFID we are attempting to
sense qualities of the physical world - in this case,
the presence or absence of particular items - the
physical world dictates the specifics of any
installation. For this reason, every sensor
installation is different.
• The possible variations are infinite, but examining
a few archetypal applications of RFID can help you
to understand the broad categories of installation.

These categories include
• a. Portals
• b. Tunnels
• c. Handhelds
• d. Forklift readers and
• e. Smart shelves.

Portals
• The word “portal” means doorway or entrance, and an RFID
portal is an arrangement of antennas and readers designed to
recognize tagged items entering or leaving through a
doorway.
• This is a common setup for warehouses, where items arrive
and leave through loading docks.
• It can also be useful for items moving between sections of a
factory, where tagged items might travel through doors (for
example, moving from storage to the assembly floor).
• Portals may also be mobile; in these applications, the reader
and antennas are built into a framework on wheels that can
be pushed into a truck or down an aisle. This is useful for
loading and unloading and for material tracking. Figure 3.5
shows a typical portal.

Tunnels
• A tunnel is an enclosure, usually over a conveyor belt, in which
the antennas (and sometimes even the reader) may be housed.
• A tunnel is like a small portal, with the advantage that a tunnel
may also include RF shielding, which absorbs reflected or
misdirected RF energy that might interfere with other readers
and antennas nearby.
• This can be useful for assembly lines or packaging conveyors
where the reader identifies the station through which an item is
currently passing on the conveyor. Figure 3.6 shows a typical
tunnel over a conveyor.

Handhelds
• A handheld reader with integrated antenna, controller,
and communications can allow personnel to scan
tagged items in situations where it is inconvenient or
impossible to move the items to a reader.
• The use of handheld RFID readers is very similar to
that of handheld bar code readers. Not surprisingly,
many of these RFID handhelds can also read bar codes
and are made by the same manufacturers that make the
bar code readers.

Forklifts
• Forklifts, too, may carry RFID readers, for the same
reason that a person might carry a handheld reader.
• Forklift manufacturers are beginning to offer RFID
readers as part of the optional equipment on their
products, just as they have offered bar code readers
and operator terminals in the past.
• One pitfall of adding forklift readers in-place is the
liability and regulatory concerns of adding equipment
to these vehicles.

A forklift with an RFID reader

Smart Shelves
• One of the most talked about but least common
applications of RFID is the smart shelf.
• Smart shelves are shelving units with antennas
incorporated into them in such a way that readers can
recognize the arrival and departure of items from the
shelves, or read all the items on the shelves on
demand.
• This potentially allows for a real-time inventory of all
the items in stock. The system can not only measure
the current stock levels of items, but it can also do
things like match item IDs against a database of
expiration dates and notify personnel about expired
items.

Configuring Readers
• Even EPC readers vary greatly by manufacturer in the
number and type of options that they offer, but some
things are relatively common.
• Readers usually support ad hoc queries of the type,
“What IDs do you see right now?” They also usually
support an asynchronous configuration, where a host
on the network essentially asks the reader to send it
any updates whenever the reader “hears” something.
• Readers that support multiple antennas usually
support two different ways of using them.

• One configuration treats all of the antennas as if they
are part of one big antenna and treats tag reads that
come in from any antenna as having come from one
logical “source.”
• Another option is to configure each antenna as if it
represents a unique location, a unique source.
• For instance, each antenna might be in its own tunnel
enclosure and represent a different stage in an
assembly process.

Single- and multiple-source
antenna configurations

• The new EPC UHF Gen2 specification requires tags to
work in conditions where two readers are active
simultaneously.
• The specification calls this a “Dense Interrogator
Environment” and prescribes two different approaches to
avoid collisions, depending on the regulatory conditions.
• Designing an appropriate placement for antennas and
readers in a production environment is a task that
requires both skill and expensive RF site survey
equipment.
• RF devices also typically require licensing and even
periodic inspection in many countries. Be sure to check
with your local authorities to avoid expensive fines.

Parts of a Reader Protocol
• Any modern reader protocol must provide certain
capabilities to operate in a production environment.
These capabilities together imply a general
structure that all reader protocols tend to follow.
• To describe these capabilities and the basic
structure of a reader protocol, we will first need to
introduce some new terms:

• Alert
An alert is a message from a reader to a host indicating a
change in reader health or containing a scheduled update of
reader health information.
• Command
A command is a message from a host to a reader that causes a
change in state in the reader or a reaction from the reader.
• Host
A host is an application or middleware component that
communicates with readers.
• Observation
An observation is a record of some value somewhere at some
time for example, the exact temperature inside a refrigeration
unit at a particular point in time, or the appearance of ID tag 42
at dock door 5 at 16:22:32 on July 23, 2005.

• Reader
A reader is a sensor that communicates with tags to
observe identities and then communicates these
observations to a host.
• Transport
A transport is a communications mechanism used by
readers and hosts to communicate with each other.
• Trigger
A trigger is some criterion, such as time of day, that
will cause some activity to occur. An example might
be a timed read trigger that causes a reader to attempt
to read any tags present every 12 minutes.

• With these terms described, we can define a reader
protocol as a set of formal rules defining how one or
more hosts and one or more readers may communicate
commands, observations, and alerts over a transport.
• Any reader protocol must deal with three major types
of communication: commands passing from the host
to the reader, observations passing from the reader to
the host, and alerts passing from the reader to the host

Flow of information in an RFID
system

• Commands
A host sends commands to a reader to cause some
reaction from the reader or to change the state of the
reader in some way. We can broadly divide the
commands a host sends to a reader into three
categories:
Configuration commands-These commands are for
the setup and configuration of the reader.
Observation commands-These commands cause the
reader to read, write, or modify tag information
immediately.
Trigger commands-These commands set triggers for
events such as reads or notifications to occur.

• Once a reader makes an observation or generates an
alert, it must communicate notifications concerning
those observations or alerts to the host.
• The communications can be initiated either by the
reader (asynchronous communication) or via
polling requests from the host (synchronous
communication).

Vendor Protocols
• Different RFID reader vendors have created
significantly different reader protocols, but all of
them perform the same basic functions
• In the following sections, we examine a simple “hello
world” RFID application using reader protocols from
two of the leading reader manufacturers, Alien and
Symbol.
• The Symbol reader we discuss is the Matrics AR-400
(Symbol acquired another leading reader vendor,
Matrics, in 2004).

Alien
• Alien Technology use the terms Interactive mode
and Autonomous mode for these two types of
communication rather than synchronous and
asynchronous, but the respective steps performed by
the reader and host are the same.
• The Alien reader accepts commands over a serial port
or through a telnet session via the Transmission
Control Protocol (TCP).
• Some configuration commands may also be supplied
through a web interface using HTTP GET and POST
commands (implemented as a web GUI).

• Alien supports notifications of observations or alerts
by email (via the Simple Mail Transfer Protocol), over
a TCP socket, or over the serial port, using several
configurable formats for the information.
• In the following example, we use an XML format to
show a TCP socket notification. The host listens on a
configurable socket.
• The reader connects to this socket, sends a notification
like the following (give or take a few lines) to that port
as XML text, and then closes the socket:

• <Alien-RFID-Reader-Auto-Notification>
• <ReaderName>Dock Reader</ReaderName>
• <ReaderType>Alien RFID Tag Reader (Class 1 / 915Mhz) </ReaderType>
• <IPAddress>192.168.0.3</IPAddress>
• <CommandPort>23</CommandPort>
• <Time>2005/01/03 01:48:00</Time>
• <Reason>EXAMPLE MESSAGE FOR CHAPTER SIX</Reason>
• <Alien-RFID-Tag-List>
• <Alien-RFID-Tag>
• <TagID>0102 0304 0506 0709</TagID>
• <CRC>87B4</CRC>
• <DiscoveryTime>2005/01/02 23:40:03</DiscoveryTime>
• <Antenna>0</Antenna>
• <ReadCount>837</ReadCount>
• </Alien-RFID-Tag>
• <Alien-RFID-Tag>
• <TagID>2283 1668 ADC3 E804</TagID>
• <CRC>9FD0</CRC>
• <DiscoveryTime>2003/01/03 01:48:00</DiscoveryTime>
• <Antenna>0</Antenna>
• <ReadCount>1</ReadCount>
• </Alien-RFID-Tag>
• </Alien-RFID-Tag-List>
• </Alien-RFID-Reader-Auto-Notification>

• Writing a client to receive these notifications is as
simple as attaching a daemon to the socket the reader
is configured to connect to and streaming the
incoming XML into a parser that updates a persistent
store of some sort.
• However, writing a complete middleware
implementation becomes much more challenging
when we consider the need to monitor and manage the
reader, configure replacement readers, and push
software upgrades to the reader as updates come out.
• Alien provides a management console for its readers,
but it cannot manage readers from other vendors or
other types of sensors.

Symbol
• The AR-400 from Symbol Technologies accepts
commands as XML over HTTP or as XML over a TCP
socket or a serial port; it also supports a vendor-
specific byte stream protocol over a TCP or serial
connection.
• Notifications may be configured as synchronous,
which Symbol calls “Query mode,” or asynchronous,
called “Publish/Subscribe mode” in the
documentation.
• The AR-400 supports the Simple Network
Management Protocol (SNMP) for alerts and
configuration and can also accept configuration as
XML or byte stream commands. It supports Ethernet
and serial transports.

• The AR-400 has an embedded HTTP server, which
provides the Reader Administration Console. To
enable notifications, we first set the Host Notification
link in the Event Notification Preferences page of the
console to the following URL
• http://host.localdomain/cgi-bin/listener.cgi
• The reader expects the servlet or CGI script at this
URL to accept an oper argument, which may be test or
notify. Our host is running its own web server and
supports CGI scripts, so when the reader makes the
following HTTP GET request:
http://host.localdomain/cgi-bin/listener.cgi?oper=te
st

• The protocol requires the host script to respond with a
properly formed HTTP response containing only the
following as content:
<Matrics>
<HostAck/>
</Matrics>
• To indicate that an event has occurred, the reader makes a
request like the following:
• http://host.localdomain/cgi-bin/listener.cgi?oper=notify
• the host should again respond with and then make a request
for an event list at:
<Matrics>
<HostAck/>
</Matrics>

EPCglobal PROTOCOL OVERViEW
• The various vendor protocols are similar in intent, but different enough
that no single client can communicate with all readers without a custom
adapter to translate each vendor’s protocol.
• EPCglobal is close to releasing a new standard for reader protocols to
accompany its newest tag standards. This new standard will provide a
minimal subset of the protocol for all vendors to implement (ensuring
basic cross-compatibility) and a way of extending the protocol for
vendorspecific features.
• At the time of this writing, EPCglobal has not yet published the Reader
Protocol Version 1.0 specification, but that document has moved into a
last-call working draft.

Layers of the EPCglobal Reader
Protocol

• Reader layer
• The Reader layer defines the allowable content and
format of messages sent between the reader and host.
This layer comprises the Open System Interconnection
(OSI) Presentation and Application layers.
• The protocol specifically allows this layer to make use of
multiple MTBs, although a particular instance will use
only one MTB at a time. Also, regardless of the MTB, the
reader can hold a conversation with only one
host at a time.

• Messaging layer
• This layer lives on top of the Transport layer and is
responsible for managing connections and security and for
packaging the host comma and reader responses and
notifications so they can pass back and forth onthe
Transport layer.
• Any encryption, authentication, or session management
occurs in this layer. This layer describes how a conversation
between the reader and host starts and stops and defines
the shape of the frame, or the envelope in which messages
pass back and forth. This layer is logically identical to the OSI
Session layer.

• Transport layer
• This is the lowest layer, and it describes either the services
provided by an OS or the hardware needed to support
networking. It corresponds roughly to the OSI Physical, Data
Link, and Network layers.
• The Transport layer is the physical connection and the
networking connection between the reader and host - for
instance, TCP over Ethernet using Cat 5 cables, an RS485
network over twisted pair, or a wireless Bluetooth
implementation.
• The following sections explore what goes on in each of
these layers.

Simple Lightweight Rfid Reader
Protocol
• The Simple Lightweight RFID Reader Protocol
(SLRRP) is an InternetDraft from the Internet
Engineering Task Force (IETF).This protocol has a
stated goal of interoperating with both ISO 18000
and EPC readers.
• SLRRP differs significantly from the EPCglobal
Reader Protocol, but it is considered a “work in
progress,” so we may see some reconciliation
between the two standards.

The RNC sits between readers and
RFID middleware

3.11 Future Protocols
• Current efforts provide a standard reader protocol
that addresses the basics of reading and writing
tags, configuring readers, and monitoring reader
health.
• Future protocols will deal with more advanced
concerns, such as how to cover an area by
extending the range of available readers when one
reader fails, and how to integrate other edge
devices (including other types of sensors) in order
to capture more complex observations.

20EC7020E -RFID AND
FLEXIBLE SENSORS
UNIT - 4
Middleware and
Information Service
Motivations- logical architecture - application level events
specification- commercial RFID
middleware - RFID Data - EPC global network - object
naming service - EPC information
services.

Motivations
• There are three primary motivations behind using
RFID middleware:
to encapsulate the applications from device
interfaces;
to process the raw observations captured by the
readers and sensors so that applications see only
meaningful, high level events, thereby lowering the
volume of information that they need to process
To provide an application level interface for
managing readers and querying RFID observations.

Components of RFID
middleware
Application Level Interface
Event Manager
Reader Adapter

Providing a Reader Interface
• Consider how applications will interface with readers
and other sensors in your physical infrastructure.
• each application write to the APIs provided by each
of the reader types, but this will not work for
anything but trivial scenarios, as a typical enterprise
is bound to use at least half a dozen different types
of readers from one or more providers.
• A reader adapter provides the means to eliminate the
vagaries of the differing readers and APIs and expose
a single abstract interface to your applications.

Filtering Events
• A typical RFID-enabled distributor or retailer with several
hundred or more stores will have hundreds, if not
thousands, of readers.
• Each of these readers will be chirping away several times
a second in order to read the RFID tags around them.
This can result in millions of RFID read observations per
second. Exposing raw observations from the readers and
sensors to enterprise applications would be akin to trying
to drink water through a fire hose.
• The process of smoothing out the raw RFID observations
coming from readers and sensors or otherwise making
them more meaningful for enterprise applications is called
event filtering. The component that provides the event
filtering functions is called the event manager.

Event volume and relevance
through different layers of an RFID
system

Providing a Standards-Based Service Interface
• One of the primary benefits of using RFID
middleware is that it provides a standardized way of
dealing with the flood of information created by the
tiny RFID tags.
• What is needed is a service-oriented interface we’ll
call this the application-level interface that provides
application-level semantics to the collection of
RFID data.

Logical Architecture
RFID and other remote sensing technologies
provide a level of automation that was not
previously possible with labeling technologies such
as bar codes that needed human intervention.
However, this level of automation requires that the
readers and sensors be monitored and managed
remotely.

• A middleware solution that operates at the edges
is best suited to monitoring and managing edge
devices. Thus, in addition to the three functions
described above, an RFID middleware solution
should also provide, or at least integrate with, a
management and monitoring interface.

Conceptual architecture for an
RFID middleware product

Application Level Events
Specification
• The ALE specification is the application-level
interface standard developed by EPC global to
allow clients to obtain filtered and consolidated
EPC observations from a variety of sources.
• The ALE interface allows clients to set up event
processing methods and request filtered events in
the form of reports. Like its predecessor Savant,
the ALE specification provides a means to push
EPC data processing nearer to the source of that
data.

The principal benefits of the ALE specification
• Standards for event management
• Extensibility
• Separation of interface from implementation
• ALE and Savant
• Key Concepts and Terminology

ALE and Savant
• Before ALE came about, the Auto-ID Center had
proposed a component called a “Savant.” The
term “Savant” generally meant any piece of
software situated between a group of data sources
(readers) and enterprise applications with the
specific aim of filtering data.

• The Savant specification was the original attempt at
providing a standard for RFID event processing, but
it focused more on how the event managers were
implemented than on the services they
provided.
• Before diving into the ALE service interface,
let’s first familiarize ourselves with some
important concepts and terms.

Event originators
• An event originator is any device that captures the
presence of an RFID tag or any other observation
from the physical world. RFID readers and
sensors are examples of event originators.
•
The ALE specification distinguishes a physical
device from a Reader (we will capitalize the term
“Reader” when it is referred to in the context of
the ALE specification).

• A Reader mapping to a single physical device
A Reader may be implemented as a single
physical device, e.g., a single- antenna RFID
reader, an EPC-compatible bar code scanner, or a
reader with multiple antennas where the
observations from all the antennas are aggregated.

• Several Readers mapping to the same physical
device
A Reader can manifest as multiple
devices, such as in the case of a reader that has
multiple antennas that are treated as distinct
sources.

• A Reader mapping to multiple physical devices
Multiple readers can be configured to
work together to derive synthesized observations.
For instance, two or more readers could be
used to triangulate location information.

Read cycles
• To understand event management, it is important
to understand how events are originated and
passed from the Readers to the ALE server and
then on to the clients of the ALE server.
• A Reader can scan for RFID tags or other physical
observations at a set frequency or on demand.
When scanning is done at a set frequency, each
scan is called a read cycle.

• The set of EPCs read in a read cycle is denoted by
an S. Four read cycles are depicted in Following
• S1 = {EPC1, EPC3, EPC4} S2 = {EPC1, EPC2}
• S3 = {EPC1, EPC2, EPC4, EPC5} S4 = {EPC3, EPC4,
EPC5}
• This means that, for example, Read Cycle 1 (S1)
returns the following observations: EPC1, EPC3,
and EPC4.

Event cycles
• An event cycle is a unit of interaction that a client uses
with an ALE service.
• For instance, an event cycle can span multiple read
cycles, and multiple event cycles can span a given set
of read cycles.
• Event cycles and read cycles are important
concepts that allow applications to specify the time
intervals or event windows for capturing events.
Because event cycles can span multiple read cycles,
they enable applications to set up logical, more
meaningful observation windows.

Interaction Models
• The interaction models supported by the ALE
specification should come as no surprise to
application developers: a client can either request
services on demand (synchronous mode) or register
for information to be sent to it when certain
conditions are met (asynchronous mode).

DATA ELEMENTS
• At its core, a client’s main purpose is to request
EPC data. It does so by providing an event cycle
specification (ECSpec) to the ALE service.
• An ECSpec specifies rules for determining the start
and end of event cycles and the reports to be
generated from them.
• It also contains a list of logical readers, as an event
cycle draws data from the read cycles of one or
more Readers. A sample ECSpec looks like this:

ECSpec
readers : List
// An ECSpec contains a list of logical readers, as an event cycle
// draws data from the read cycles of one or more Readers.
Boundaries : ECBoundarySpec
// Specifies how the beginning and the end of event cycles are
// to be determined. reportSpecs : List
// Specifies a list of reports to be returned after an event cycle
// is executed. includeSpecInReports : boolean
// If set to true, the ALE implementation includes the complete
// ECSpec in the reports that are generated.
<<extension point>>

ALE Service Interface
• ALE specification requires is that the vendor
implementations are compliant with the WS-I
specification for its interface schema and SOAP
bindings.
Usage Scenarios
Synchronous mode
Polling mode.
Asynchronous mode

Synchronous mode
• Make a one-time request for events coming from
a set of Readers and, along the way, specifying
how the raw EPC observations should be filtered
and grouped. The ALE specification calls this
mode of interaction “immediate.”
• Immediate mode
• Immediate mode is one of the two synchronous
methods available to access an ALE service. The
client first creates and configures an ECSpec, and
then invokes the “immediate” service of the ALE
server

Sequence diagram for immediate
mode

Polling mode.
• A client that wants to get regularly scheduled
updates rather than one- tme reports, on EPC event
data would use the ALE server’s polling interface.
• Polling is executed synchronously

Sequence diagram for polling
mode

Filtering and Grouping
• The ALE specification provides two distinct
mechanisms for event processing: filtering and
grouping.
• Filtering provides capabilities to tune into specific
patterns in the event data. Grouping provides means
to group data collected from different Readers and
over multiple event cycles.

• Clients can specify filtering schemes with the help
of two pattern lists: includePatterns and
excludePatterns. An EPC is included in the final
report if it matches at least one pattern in the
includePatterns list and does not match any pattern
in the excludePatterns list.
• Grouping patterns use mechanisms similar to the
ones described above for filtering, but in addition to
decimal, wildcard (*), and range specifiers, X is
used as a special value in the URI fields.

URI field values for grouping
patterns
• Pattern URI field
• Description
• *
• Group together all the values in this field.
• X
• Create a different group for each distinct value of this field.
• Number
• Only EPCs having the specified number in this field will belong to this
group.
• Range [Low-high]
• All the EPCs whose value for this field falls with in the specified range
will belong to this group.

Data Model
• If you are not going to be programming using ALE-
compliant middleware, skip this section
• EC Spec provides a means to specify the data that a
client is interested in receiving; the client specifies the
names of Readers from which it wants to receive data,
and how the event cycles map to the Readers’ read
cycles.
• The EC Boundary Spec data type is used for
specifying the event boundaries. Instructions for
filtering (ECFilterSpec) and grouping (ECGroupSpec)
the Reader observations are provided in the EC Report
Spec.

• The EC Report Spec also provides specifications for
what data should be reported back and how.
• The EC Report defines what kind of reports the ALE
servers will produce. An EC Report provides a single
report produced within an event cycle. Data within an
EC Report is grouped using EC Report Group
instances. Each instance of EC Report Group
represents one grouping of EPCs within an ECReport.
• The EPCs can be reported in hexadecimal or decimal
format. EC Report Group List Member type provides
the template for how the EPCs are reported back.

ECSpec
1.One or more reports are generated from an event
cycle. The specifications for the reports that are
generated are described by ECSpecs.
2. ECSpec is one of the two primary data types
associated with the ALE API (the other one is
ECReport).

• ECBoundary Spec
• The ECBoundary Spec specifies the start and end of
event cycles.
• startTrigger : ECTrigger
• stopTrigger : ECTrigger
• repeatPeriod : ECTime
• duration : ECTime
• stableSetInterval : ECTime
• <<extension point>>

An event cycle is started if one of the following
conditions occurs:
• The specified start trigger is received while an ECSpec
is in the Requested state.
• The repeat period has elapsed from the start of the last
event cycle and the ECSpec is still in the Requested
state.
An event cycle ends when one of the following
conditions is met:
• The time interval specified in the duration field expires.
• The stop trigger is received.
• The ECSpec transitions to the Defined but Unrequested
state.

• ECTime
• The ECTime defines a span of time measured in units
of physical time.
duration : long
unit : ECTimeUnit
• ECTimeUnit
• ECTimeUnit is an enumerated type that denotes
different units of physical time to be used in an
ECBoundarySpec
<< Enumerated Type>>
MS // Milliseconds

• ECTrigger
• A URI denoted by ECTrigger shows a start or stop
trigger for an event cycle. The interpretation of this URI
is left to the ALE implementations.
triggerValue: URI
• ECReportSpec
• An ECReportSpec describes a report returned from the
execution of an event cycle and provides rules for what
set of EPCs should be considered for reporting. It
provides these rules by specifying whether all the
currently read EPCs should be reported and, likewise,
whether the additions or deletions from the previous
event cycle should be reported.

• EC Termination Condition
• ECTermination Condition is an enumerated type specifying how
an event cycle should end.
• <<Enumerated Type>>
• TRIGGER
• // Event cycle should end when an explicit stop trigger is
received. DURATION
// Event cycle should end when the duration expires.
• STABLE_SET
// Event cycle should end when the observered EPCs have been
stable
• // for a duration.
UNREQUEST
• // Event cycle should end when there are no requesting/subscribed
• // clients.

• ECReport
• An ECReport specifies a single report within an event cycle.
Data within an ECReport is grouped using ECReportGroup
instances.
• reportName : string
• // Report name is a copy of the reportName field from the
ECReportSpec.
• group : List
• // Specifies a list of ECReportGroup instances.
• ECReports
• Output from an event log is described in ECReports. specName :
string
• date : dateTime ALEID : string
• group : ECGroupSpec totalMilliseconds : long
• terminationCondition : ECTerminationCondition spec : ECSpec
•

• ECReportSetSpec
• ECReportSetSpec is an enumerated type that shows
the set of EPCs to be used for filtering and output.
• <<Enumerated Type>>
•
CURRENT ADDITIONS DELETIONS
• ECReportOutputSpec
• provides the layout of the event cycle report.
includeEPC : boolean
• includeTag : boolean includeRawHex : boolean
includeRawDecimal : boolean includeCount : boolean

• ECReportGroup
• A single group within an ECReport is presented by an
ECReportGroup.
• groupName : string
• groupList : ECReportGroupList groupCount :
ECReportGroupCount
• ECReport GroupList
• An ECReport Group shows an ECReport Group List when any
of the include EPC, include Tag, include RawHex, or include
RawDecimal parameters of the corresponding ECReport
OutputSpec are true.
• members : List // List of ECReportGroupListMember instances.

• ECReportGroupListMember
• An ECReportGroupListMember allows multiple EPC formats
to be included in the reports. The URIs in the
ECReportGroupListMember must correspond to the Boolean
values in the ECReportOutputSpec. For instance, if the value
for the includeEPC attribute of the ECReportOutputSpec is
true, the URI value for epc must be non-null. epc : URI
• tag : URI rawHex : URI
• rawDecimal : URI
• ECReportGroupCount
• O An ECReportGroupCount is part of an ECReportGroup. The
includeCount of the corresponding ECReportOutputSpec must
be true to get an ECReportGroup.
• count : int

• ECFilterSpec
• An ECFilterSpec describes which EPCs are to be
included in the final list of EPC patterns.
• includePatterns : List excludePatterns : List
• EPCGroupSpec
• An ECGroupSpec defines filtered EPCs and how they
are grouped together for reporting.
• patternList : List

Commercial RFID Middleware
• The four middleware products included in our
discussion each provide the core functions of
encapsulating reader interactions, managing
events, and providing a high-level service
oriented interface for applications.
• In addition to these core functions, these products
provide varying degrees of management and
monitoring capabilities, service-oriented
architecture integration capabilities, and built-in
adapters to various ERP packages

Sun Microsystems
• Sun Microsystems was one of the early entrants into the
RFID market. Sun provides a Java-based RFID middleware
platform called the Sun Java System RFID Software.
• Sun’s RFID software is designed specifically to provide high
levels of reliability and scalability for your EPC network,
while also simplifying the task of integrating with multiple
existing backend enterprise systems
• The four components of the project are
RFID Event Manager,
RFID Management Console,
RFID Information Server, and
a software development kit (SDK) for creating adapters and
standalone applications:

RFID Event Manager
• The RFID Event Manager is a Jini-based event
management system that facilitates the capture,
filtering, and eventual storage of EPC events
generated by RFID readers connected to the
network.

RFID Management Console
• The RFID Management Console (MC) is a browser-
based graphical interface used to manage and
monitor the RFID Event Manager. It allows the user
to view and modify the RFID reader attributes and
components of the Event Manager, such as filters and
connectors.
• The RFID MC uses a JDBC-compliant relational
database to persist reader grouping information,
alarms, and system settings such as access rights and
email configuration. It is qualified with Oracle 8i,
Oracle 9i, Oracle 10g, and PostgreSQL 8.0.3.

RFID Information Server
• The RFID Information Server (IS) is a J2EE application that serves as
an interface for the capture and query of EPC-related data. EPC-related
data can include tag observation data from Event Managers as well as
information that maps EPCs to higher-level business data.
• 0
• The RFID IS is typically used to translate a set of low-level
observations into higher-level business functions. It has been qualified
on the Sun Java System Application Server Version 8.1 and on BEA
Weblogic 9.0. Other applications interface with the IS through XML
message exchange.

SDK
• The well-documented SDK allows developers to
extend the product if they choose to create a custom
application rather than using the components as they
are shipped.
• Version 3.0 of this product adds support for the
latest readers and printers. The product is built on top
of Jini 2.0.1, Rio 3.1, the Java Web Services
Developer Pack 1.5, and the Sun Java System
Application Server 8.1, but it is designed for
maximum portability and supports a wide variety of
platforms, including Solaris, Linux, Windows XP, and
an ALE implementation for J2ME CDC (embedded
devices).

Sun’s Java System RFID
middleware

ConnecTerra / BEA
• ConnecTerra’s primary product, RFTagAware, is a
software infrastructure platform
• Dr. Ken Traub was the lead author for the Application
Level Events specification.
• The RFTagAware Edge Server, a piece of software
deployed on or near a device, processes the raw tag
information and, based on any number of outstanding
queries (known as Event Cycle Specifications),
delivers qualifying results to any number of
subscribing applications.

RF Tag Aware provides the following capabilities
• Data filtering and aggregation-low
• Monitoring and managing an RFID infrastructure-
Administration Console
• Integrating data with enterprise applications
• Rapid application development
• Globe Ranger-The iMotion software platform
incorporates visual tools to simplify solution
development, deployment, and management
Edge Device Management
Edge Process Management
Enterprise Management Console
Visual Device Emulator

ConnecTerra’s RFTagAware RFID
middleware platform

GlobeRanger’s Event Workflow
Editor

RFID Data
• RFID data can be classified under two broad
categories: event data and master data.
• Event Data
• Event data is tied to a specific moment in time and
communicates the whereabouts of an RFID-tagged
asset as it moves through a supply chain.
• An example of event data is: “At 2:01 p.m. on 9
October 2005, EPC X was observed at Location L.”

• In essence, RFID event data is made up of
observations of the existence of some thing at some
place at some time. The following list covers these
elements in more detail.
• Identity-SGTIN, a GRAI, or an SSCC.
• Location
• Time

Master Data
• Master data provides supporting contextual or
reference information about the event data.
• Generally, your RFID master data will not grow at the
same pace as the event data.
• Data Volume-Depending on the size of your RFID
infrastructure and the granularity at which you need to
track your assets, RFID data volume can potentially
overwhelm your networks and storage
• Data Storage

The Epcglobal Network
• EPCglobal envisions a network of EPC-enabled
data services that is used by trading partners to
enable near-real-time tracking information on items
in their supply chains
• The EPCglobal Network introduces a few dedicated
components, such as the Object Naming Service
(ONS) and the EPC Information Services (EPCIS),

The EPCglobal Network is made
up of five principal services
• Assigning unique identities-Universal Product Code
(UPC) or bar code, the EPC is an identification system for
products
• Detecting and identifying items-The identification
system consists of EPC tags and readers. An EPC tag
contains a microchip attached to an antenna. The EPC is
stored on this microchip.
• Collecting and filtering events
• Event management middleware is needed to facilitate
the collection of observations from the readers and filter
and group them for consumption by the applications.

• Storing and querying events-The EPC Information
Service enables users to exchange EPC data with trading
partners.
• Locating EPC information- To enable trading partners
to share EPC observations, it is necessary to provide
lookup services that can locate repositories for the
required EPC data.
• The EPCglobal Network envisions two types of
repositories: static data repositories from a
manufacturer (for data such as expiration dates,
manufacturing timestamps, and so on) and dynamic
repositories from other supply chain participants
(including information such as track-and- trace
observation data, temperature readings, and other
observations made as a product moves through the
supply chain).

The Object Naming Service
• The ONS is the authoritative source for locating
EPC Information Services instances. For example, a
retailer can locate a manufacturer’s EPCIS instance by
querying an ONS server.
• To tagging medicines with RFID tags and installing
readers to record the inventory, two things are needed
a service that maps EPC codes to the relevant
product information, and a service that can provide
the address of a particular EPC code’s information.
 EPCglobal calls these services the EPC Information
Services and the Object Naming Service, respectively.

• One of the overarching principles behind the design of
the ONS was that it should leverage the existing
Internet standards and infrastructure wherever
possible. Following this principle, the ONS uses the
Domain Name System (DNS) for resolving EPCs.
• The EPC query and response formats follow the DNS
standards. As aresult, the EPC being queried is
converted to a domain name and the result is returned
as a valid DNS resource record.

DNS
• The Directory Naming Service (DNS) forms the
backbone of the Internet and represents one of the
largest and most successful implementations of a
distributed database anywhere

Understanding the ONS
• The steps involved would thus go something like
this
An EPC event manager receives a tag reader event
and in turn sends the sequence of bits containing
the EPC from the tag to an RFID integration server.
• Bit Format: [10 00000000000000101100
00000000000001111
000000000000000001000001]
• Decimal Format: 2.44.15.65

Types of Name Servers
• The RFID integration server converts this bit
sequence into the Universal Resource Identifier
format and sends it to a local ONS resolver.
• urn:epc:2.44.15.65
• The ONS resolver converts the URI into a domain
name and issues a DNS query for NAPTR (naming
authority pointer) records for that domain:
• 15.44.2.onsroot.org

• The root of the domain name tree is denoted by a
single dot and is called the root domain.
• The authoritative name servers for the root domain
are called root name servers.

The URI form of the EPC is converted into DNS form using the following process:
• Remove the urn:epc: header. In our example, the
URI is urn:epc: 2.44.15.65
• Removing the header gives us 2.44.15.65.
• Remove the serial number field from the EPC,
giving us 2.44.15.
• Invert the order of the remaining fields, giving us
15.44.2
• Append “.onsroot.org,” giving us
15.44.2.onsroot.org.

Understanding ONS Query Result Formats
• The DNS resource record consists of the following
fields: Order, Pref, Flags, Service, Regexp, and
Replacement

• Order
• The order field describes the equivalence of NAPTR rows returned
from a load-balancing perspective.
• Pref
• The Pref field is also used to designate priority with regard to
interpreting the rows in the result set. Records with lower Pref
numbers should be processed before those with higher numbers.
• Flags
• If the Flags field is set to “u”, it means the Regexp field contains a
URI. The corresponding value in the Service field provides an
indication of the type of service.
• Service
• The Service field is used to designate different types of services. The
format of this field is EPC+service_name. The legal values for service
_name include pml, html, xmlrpc, and ws. The EPC portion is used to
differentiate it from other types of NAPTR records, while the
+service_ name portion is used to describe the service class.
• expression.

• Regexp
• The Regexp field specifies a URI for the service being
described. The service types persently envisioned by
EPC global only need the hostname and additional path
information for description, but the regular expression
type is used because DNS uses NAPTR records to
conditionally rewrite URIs. The POSIX Extended
Regular Expression format is used to describe this field.
• Replacement
• This field specifies the replacement portion of the
rewrite

• The service codes are as follows:
• PML
• This method is used to obtain Physical Markup
Language (PML) documents about a product.
• HTML
• This service returns a URI that will resolve to static
web content. This method can be used to access a web
site that contains existing product information. An
application would get this information from the RFID
integration server and would typically display the
contents of this page using a web browser.

• XMLRPC
• The URI returned by this service will resolve to a
server capable of responding to XMLRPC requests. An
application would call methods on this server by
POSTs containing XML similar to the example below:
• WS
• O This method is used to connect to a web service that
can get detailed product tracking information by
calling public interfaces made available by
manufacturers or distributors. The RFID integration
server in this case will receive a Web Service
Definition Language (WSDL) file that describes the
aforementioned web serviceS

The EPC Information Services
• The EPCIS is an upcoming EPCglobal standard
whose goal is to enable disparate applications to
leverage EPC data via EPC-related data sharing,
both within and across enterprises.
• The EPCIS defines a standard interface for
capturing and sharing EPC- related data.

20EC7020E -RFID AND FLEXIBLE
SENSORS
UNIT 5
Flexible Sensors
World of wearables- Attributes of wearables-Textiles
and clothing: The meta wearable –Challenges and
opportunities- Future of wearables-Need for wearable
haptic devices-Categories of wearable haptic

World of wearables (WOW)
• In today’s digital world the term “wearable” has a new
meaning! Today it brings up images of accessories
such as a smartwatch on a business executive’s wrist, a
head-mounted display worn by an immersive gamer, a
tiny sensor on a cyclist’s helmet, or a smart garment a
runner uses to track and monitor her steps.

WOW: the world of wearables
enabling digital lives.

The role of wearables
• wearables can perform the following basic
functions or unit operations
Sense
Process (Analyze)
Store
Transmit
Apply (Utilize)

Unit operations in obtaining situational awareness:
the role of wearables.

Data-information-knowledge-value paradigm

Big data analysis
• The emerging concept of big data Park and
Jayaraman discussed the role of wearables in
relationship to “big data”.
• Big data refers to large amounts and varieties of
fast-moving data from individuals and groups that
can be processed, analyzed,and integrated over time
to create significant value by revealing insights into
human behavior and activities

Medical loss ratio and wearables
• Wearables enable this remote health monitoring of
patients. The health data can be wirelessly sent to
the physician’s office by the wearable, negating the
need for office visits. Consequently, the cost of care
decreases. Moreover, the ability to continuously
track patients’ health can help identify any potential
problems through preventive interventions and thus
enhance the quality of care while eliminating
unnecessary procedures since the cost of prevention
is significantly less than the cost of treatment.

The Ecosystem Enabling Digital Life
• The advancements in, and convergence of,
microelectronics, materials, optics, and
biotechnologies, coupled with miniaturization, have
led to the development of small, cost-effective
intelligent sensors for a wide variety of applications

Smart mobile communication devices
• A key component of the ecosystem is the smart
mobile communications device smartphone and/or
tablet that provides a platform for “information
processing on the go” for anyone, anytime, and
anywhere. The global mobile data traffic is
projected to increase from 19.01 exabytes per
month in 2018 to 77.5 exabytes per month in 2022
at a compound annual growth rate of 46%.

Social media tools
• Easy-to-use social media tools such as Facebook,
Instagram, and Twittercomplete the eco-system that is
digitizing, connecting, and continuously transforming
our lives. Indeed, virtu-ally everything is being
captured and is being reduced to a sequence of 0 s and
1 s inside the hardware, but with significant value to
the user/viewer on the outside! Now that we have
defined a wearable, established the important role of
wearables, and have defined the components of an
ecosystem to enable digital life with wearables at its
core.

Attributes of Wearables
• A sensor is defined as “a device used to detect,
locate, or quantify energy or matter, giving a signal
for the detection of a physical or chemical property
to which the device responds” .Not all sensors are
necessarily wearable
• From a physical standpoint, the wearable must be
lightweight and the form factor should be variable
to suit the wearer

• The wearable motherboard – A user-centric approach
to the design of wearables
• Research in flexible electronics
 printing electronics (thin-film transistors, thin-
metal films, nanomaterials, and carbon nanotubes,
among others) onto elastomeric substrates resulting in
“electronic skins” with pressure and temperature
sensing capabilities

Requirements For Creating And Developing A Useful Wearable
Sensor System.
• Different types of sensors
The latest trends in commercial wearables

Textiles and Clothing : The Meta-wearable
• Wearable Motherboard Architecture

Applications of wearables
• The wearable system is responsible for sensing,
processing, analyzing, and transmitting the results
to the user.
• The number of connected wearables worldwide is
expected to increase from 325 million to 1.1 billion
in 2022

Textile-based wearables in the market

Challenges and Opportunities
• The success of any innovative product in the marketplace
depends on:
• Its effectiveness in successfully understanding the user’s needs
and meeting them
• Its compatibility with or similarity to existing products or
solutions
• The extent of behavioral change needed to use the new product
• The reduction in the cost of current solutions or technologies it
aims to supplant
• The improvement in the quality of service (or performance)
• The enhancement of the user’s convenience

Technical challenges
• The success of wearables depends on the ability to
connect them seamlessly in a body worn network.

Making a business case:
stakeholders and metrics

The Future of Wearables : Defining the Research
Roadmap
• The paradigm of “Information Anywhere, Anytime, Anyone”
is a reality today.
• Tactile and haptic information is essential for completing
tasks and control operations. Haptic feedback systems can be
classified into three types according to their mechanical
grounding configur
• ation:
• Grounded Type
• Non-grounded Type
• Wearable Type

Research roadmap for wearables:
need for a transdisciplinary approach

Need for Wearable Haptic Devices
• Haptic feedback systems can be classified into three
types according to their mechanical grounding
configuration:
 Grounded Type
 Non-grounded Type
 Wearable Type

Categories of Wearable Haptic
• Force Feedback
• Vibro-Tactile Feedback
• Electronic Feedback

UNIT PPT - 20EC7020E -RFID AND FLEXIBLE SENSORS

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