EPCglobal CONCEPTS IN THE SUPPLY CHAIN

1

• EPCglobal CONCEPTS IN THE SUPPLY CHAIN

Peter H. Cole Professor of RFID Systems
University of Adelaide Director of the Auto-ID
Laboratory _at_ Adelaide
2
EPCglobal CONCEPTS IN THE SUPPLY CHAIN

• Modified by Alfio R. Grasso
• Deputy Director
• Auto-ID Lab, ADELAIDE

3
Outline

• RFID in the supply chain
• The emerging EPC technology
• The key concepts
• Physics of RFID
• RFID systems
• Coupling calculations
• RFID protocols
• The work of Auto-ID Labs
• Conclusions

4

• PART 1
• RFID IN THE SUPPLY CHAIN

Photos courtesy of Mirrabooka Systems
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Tag reading
The black spot
Reader Tx typically 1W, 6dB gain Antenna But
propagation loss, resulting Rx at Tag typically
µW On tag, Some RF used for DC power, some used
for modulation More loss back to Reader
Rx Therefore a very weak reply is obtained
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Matrics (Symbol) Tags
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Alien Technology Tags
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Intermec Tags
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RFID Readers
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RFID Antenna(s)
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The supply chain
Global Supply Chain
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Example applications

• What can you do with this technology ?
• Supply chain benefits
• Reduce out of stocks, reduce inventory, speed up
  delivery, check freshness, track and trace,
  produce to demand, identify sources of diversion,
  identify counterfeiting, theft prediction, faster
  recalls
• Consumer benefits
• Direct order from home, smart appliances, (e.g.
  microwave, washing machine, refrigerator), smart
  healthcare, assisted living
• New and less expected benefits
• Customized products, smart recycling,
  checkout-less stores

13

• PART 2
• THE EMERGING EPC TECHNOLOGY

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The Auto-ID Center

• Global, industry funded research program
• Massachusetts Institute of Technology (1999)
• Cambridge University (2000)
• University of Adelaide (2002)
• Japan, China, Switzerland (2003)
• Mission
• Create the internet of things
• Research for the benefit of mankind

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About the Center

• End User Sponsors Include
• Procter Gamble, Gillette, Uniform Codes Council
  (UCC), CHEP International, EAN International,
  International Paper, Philip Morris Group, Johnson
  Johnson, Wal-Mart, Yuen Foong Yu, United States
  Postal Service, Westvaco, Unilever,
  Kimberly-Clark, Tesco, Coca-Cola, Knight Ranger,
  Dai Nippon Printing, Department of Defense,
  United Parcel Service
• Vendor Sponsors Include
• NCR, Savi Technologies, Sun Microsystems, Flint
  Ink, Markem, Invensys, Sensormatic, Cashs,
  Rafsec, Flexchip, Alien Technology, Philips
  Semiconductor, SAP, Checkpoint, ThingMagic,
  Accenture, AC Nielson, Avery Denison, Ember
  Corporation, PWC, Accenture
• Trade Bodies
• AIM Global, GCI, GMA, FMI, NACS, NACDS, AIM,
  POPAI, IMRA, ARTS, UTSA

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The Auto-ID Center Vision

• The internet of things
• Physical objects connected via the internet
• Simple identifying labels on objects
• Unlimited associated data in a data base
• Connections via an intranet or the internet
• Freely available world wide standards
• High performance protocols and software
• A scalable system not choked by expansion

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• PART 3
• THE KEY CONCEPTS

Photo courtesy of Sugar Research Institute
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Key concepts then

• The Electronic Product Code (EPC)
• Tags bearing it and readers reading it
• The Object Name Service (ONS)
• The Physical Mark-up Language (PML)
• Smart scalable networking for the physical world
• The savant, an event manager and router

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Key concepts now

• Electronic product code
• Formats for various applications
• ID system
• Tags and readers
• EPC middleware
• Replaces the savant
• ALE engine and interfaces
• Performs filtering a data routing for clients

• Discovery services
• ONS discovery service
• Discovery services for events
• EPC information services
• Enables users to securely exchange information
  with trading partners
• EPCIS Capturing
• EPCIS Accessing

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Use of electromagnetic fields

• Coupling is via electromagnetic fields
• There is little margin for poor performance
• Tag receives so little power
• Reply is even weaker
• Electronic Circuit has a threshold of operation
• Electromagnetic Wave behaviour influenced by the
  environment
• Metal, Moisture, etc!
• RFID is a technology that is working on the edge
  of performance
• We must understand their properties
• Many reasons why a poorly configured RFID system
  will not work

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• PART 4
• THE PHYSICS OF RFID

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The field vectors

• A full theory of electrodynamics, including
  the effects of dielectric and magnetic materials,
  must be based on the four field vectors
• Electric field vector E
• Magnetic field vector H
• Electric flux density vector D
• Magnetic flux density vector B

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Faraday Laws Free Space

• Electromagnetic fields are represented by curved
  lines in 3D Space. At any point in space the
  field has a strength and direction.
• In free space only two of the 4 are needed
• E - Electric Field Vector
• H - Magnetic Field Vector
• E describes the force that will be experienced by
  a charge at that point
• H describes the force that a short wire carrying
  a current will experience at that point

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Faraday and media

• The additional vectors D and B are flux densities
  and are required to describe the properties when
  polarised or magnetised media are present.
• D - Electric flux density vector
• B - Magnetic flux density vector

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Material state vectors
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Laws in differential form Maxwells Equations
Vortex

• Two basic forms of field
• Vortex Field lines go in closed loops (top 2)
• Source Fields emerge outward from a source
  (bottom 2)

Source
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Propagation

• Maxwell's equations tell us that even in the
  absence of charges or currents at a point, a
  varying field (either E or H) will create a
  vortex of the other type of field (H or E).
• Predicted Electromagnetic propagation of waves.

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Electromagnetic propagation
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Electromagnetic waves

• They propagate with the velocity of light
• (Light is an electromagnetic wave)
• Velocity c is 300,000,000 m/s
• Wavelength - frequency relation is c fl
• At 13.56 MHz 3108/13.56106 22 m
• At 915 MHz 3108/915106 328 mm
• But not all electromagnetic fields are
  propagating waves some are just local energy
  storage fields

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Energy Storage

• From Maxwells equations
• An electric current can create a vortex of
  magnetic field
• Electric charges can be a source of electric flux
  density
• Such field have the following properties
• They can store energy per unit volume locally,
  but diminish rapidly (1/r3)
• They can cause energy to propagate away from the
  source

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Boundaries

• Maxwells equations also tell us what happens
  near a metallic surface
• Electric Field is perpendicular to the surface
• Magnetic Field is tangential to the surface

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Boundary Condition electric field
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Boundary Condition magnetic field
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The basic laws how they work

• Gausss law
• Electric flux deposits charge
• Electric field cannot just go past a conductor,
  it must turn and meet it at right angles
• Faradays law
• Oscillating magnetic flux induces voltage in a
  loop that it links

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Near and far field distributions

• Electric field launched by an electric dipole
• There is also a magnetic field not shown
• Near the antenna a source field is created
• Far field a vortex is created

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Fields of a Magnetic Dipole(oh dear)
Near Field
Far field
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The radian sphere

• At br 1, r l/2p, and
• The phase factor e-jbr is one radian
• Inside this sphere the near field predominates
• Outside this sphere the far field predominates

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Near and far fields

• The far field is an energy propagating field
• The near field is an energy storage field
• Near field - far field boundary is l/2p
• Boundary
• 13.56 MHz 3.5 m
• 915 MHz 52 mm

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• PART 5
• RFID SYSTEMS

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Issues in RFID Design

• Active or passive
• Operating frequency
• Electric or magnetic fields or both
• Material (SAW) or microelectronic (MBS)
• Focus on passive systems, active for the future?

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The usual way backscatter

• The most popular technology
• Tag contains a microcircuit and an antenna
• Tag is powered by the interrogation beam
• Frequency of that beam is chosen for good
  propagation
• Tag contains an internal oscillator
• Frequency of that oscillator is chosen for low
  power consumption
• Reply is offset from the interrogation frequency
  by a small amount

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Microelectronic Backscatter

• Concept can be applied from 10 MHz to 10,000 MHz
• Low propagation loss points to coupling using the
  far field
• Low power consumption requires a low frequency
  microcircuit
• Reply is by modulation of the interrogation
  frequency

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Relevant Issues

• Range is determined largely by the ability to
  obtain sufficient rectified voltage for the label
  rectifier system
• High quality factor resonance becomes important
  in small tags
• Relates to the need to obtain a large amount of
  stored energy by tuning, i.e. exploiting
  resonance
• But High Q tags can be de-tuned by the
  environment in proximity
• Reply is at sidebands of the interrogation
  frequency

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Interesting features

• Near and far fields
• Energy storage in the near field
• Energy propagation in the far field
• Radian sphere (rl/2p) is the boundary
• For small tag antennas
• Antenna gain or directivity in the far field is
  usually 1.5
• Tag will have a preferred orientation
• Nulls for linear tag antenna
• Some tags employ dual antennas
• No far field radiation in the polar direction
• Plenty of near field on the polar axis

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Label antennas

• Magnetic field free space
• Magnetic field against metal (boundary
  conditions)
• Electric field free space
• Electric field against metal (boundary
  conditions)
• Electromagnetic field
• Very small antennas respond to either the
  electric field or the magnetic field
• Somewhat larger antennas respond to both

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Planar printed coil

• 13.56 MHz tag
• Magnetic field normal to plane of tag, i.e.
  coming out of or into the slide
• Induced voltage in coil
• Voltage magnified by resonance, coil tuned to
  input capacitance of the circuit
• Not suitable for mounting on metal, but can mount
  normal to metal surface.

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Ferrite cored solenoid
Suitable for placing against metal
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Electric field bow tie
Small antenna that just respond to electric
field, which in this case is in the horizontal
direction
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Electric field box structure
Electric Field is vertical, bottom plate could be
placed on the metal surface.
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Electric Field Boundaries
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Electromagnetic field antenna

• Dimensions are no longer a small fraction of a
  wave length, so it responds to both electric and
  magnetic fields
• Operating principles are less clear

52

• PART 6
• COUPLING CALCULATIONS

Photo taken at Hendersons Automotive Technologies
Pty Ltd
Photo courtesy of the National Library Board
Singapore
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Field creation structures

• Near magnetic field
• Made by current carrying loops
• Near electric field
• Made by charged electrodes
• Far electromagnetic field
• Made by propagation from an originally near field

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Fields

• In the near field we can create either electric
  or magnetic fields
• In the far field (propagating wave) both magnetic
  and electric fields are created in equal (energy
  stored in a unit volume)
• However, in the far field multi-path propagation
  (reflections) can create standing waves, such
  that there are regions of extinction of electric
  field (nulls) and doubling of magnetic fields,
  and vice versa
• Hence good to have diversity by either moving the
  tag past a reader antenna, or having the reader
  antenna moving in relation to the tag
  (multiplexed antennas)

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Near and far field coupling theories

• Common feature a label driving field is created,
  how much signal can be extracted?
• In the near field of the interrogator, the
  driving field is mostly energy storage, and the
  amount radiated does not affect the coupling, but
  does affect the EMC regulator.
• Various techniques to create energy storage
  without radiating are then applicable.
• Some theorems on optimum antenna size are of
  interest.
• In the far field of the interrogator, the
  relation between what is coupled to and what is
  regulated is more direct, and such techniques are
  not applicable.

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Far field coupling theory

• In the far field the power received by the label
  depends upon the power flow per unit area (label
  size).
• Ae is therefore a Figure of Merit
• The larger the wavelength ? the better!
• The received power is NOT magnified by resonance,
  but resonance may be used for power matching!

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Near field coupling theory

• In the near field, the power received by the
  label depends on the energy stored per unit
  volume in the space occupied by the label
• Vc is the Figure of Merit
• Power received is magnified by resonance

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Measures of exciting field

• Near field antennas, the strength of excitation
  is reactive power density per unit volume Wv
• Far field antennas, the strength of excitation is
  the power flow per unit area Sr

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Significant conclusions

• Coupling volumes for well shaped planar electric
  and magnetic field labels are size dependent and
  similar

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Optimum Frequency?

• Coupling Volumes are similar!
• Ae Figure of Merit suggests that for lower
  frequencies of operation, the longer the
  wavelength, then in the far field this leads to a
  large effective area.
• So what is wrong with operation at low
  frequencies?

61
Quality Factors

• Radiation quality factors for both types of label
  formed within a square of side L are size
  dependent and similar
• These are calculated results for sensibly shaped
  antennas
• These show that by the time such antennas are
  matched, the Q factors required are so large,
  that operating bandwidths are impossibly small.
• High Q antennas are prone to detuning due to the
  environment.

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Optimum operating frequency
The optimum frequency for operation of an RFID
system in the far field is the lowest frequency
for which a reasonable match to the radiation
resistance of the label antenna can be achieved,
at the allowed size of label, without the label
or matching element losses intruding.
63

• PART 7
• RFID PROTOCOLS

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What is a protocol?

• Signalling waveforms
• Command set
• Operating procedure
• A back end interface
• whereby the identities of a population of tags
  in the field of a reader may be determined, and
  the population otherwise managed.

65
Constraints on protocols

• Electromagnetic compatibility regulations
• Differ with frequency range and jurisdiction
• Some convergence is occurring
• Reader to reader interference
• Readers confusing tags
• Readers blocking other reader receivers
• Simplicity (as reflected in chip size)
• Maybe that influences reliability as well

66
Auto-ID Center protocols

• The Auto-ID Center defined
• The Class 1 UHF protocol
• The Class 1 HF protocol
• The Class 0 UHF protocol
• EPCglobal has defined in addition
• Class 1 Generation 2 UHF protocol

67
Why are they different?

• Different field properties at HF and UHF
• Near and far field different field confinement
• Different field penetration in materials
• Different silicon circuit possibilities and costs
• Different electromagnetic regulations
• Read only memory technologies enable
  miniaturisation
• A high performance UHF system was available and
  was modified by the Center to manage privacy
  concerns

68
Protocols the major divide

• Tree walking
• More forward link signalling
• Prolonged periods of interrupted signalling
• Partial information of tag population remains
  relevant
• Adaptive round (terminating aloha)
• Less forward link signalling
• Long periods of un-modulated reader carrier
• Reader signalling is less
• No information from one response about others

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Characteristics similarities

• Both can select subsets of tags for participation
• Overt selection may reveal what is selected
• Forms of less overt selection are possible
• Tag sleeping has a role in both

70
Tree scanning concepts
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Concept of the adaptive round

• Labels reply once per round, in randomly chosen
  slots
• A group of n slots forms a round
• The number of slots in a round varies as needed
• Tags giving already collected replies moved to
  slot F

72
The C1G2 protocol

• Labels have an adjustable probability of replying
  on each query or repeated query
• Probability is adjusted to about a third
• Empty slots, singly occupied slots and multiply
  occupied slots are roughly equi-probable
• A wide range of forward and reverse signalling
  parameters are defined
• Some of them allow for narrow band reply
  signalling separated from the interrogation
  carrier

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• PART 6
• CURRENT DEVELOPMENTS

74
Auto-ID Center accomplishment

• By September 2003
• Tag reading protocols
• UHF Class 1
• UHF Class 0
• HF Class 1
• Tags (commercial chips to all protocols
  available)
• Savant
• Data filtering and event management software
  system
• Version 1 distributed, version 2 in development
• Field trial
• Three phases, then nearing completion
• PML
• Two phases of development
• Establishment of research laboratories
• USA, England, Australia, China, Japan, Switzerland

75
Transformation to Laboratories and EPCglobal

• Transformed
• 26 October 2003
• Auto-ID Labs
• Performs fundamental research related to EPC
  System
• Builds communities not already using EPC System
• Australasian Adoption Research Initiative
• EPC Global
• Manages and develops standards
• Markets EPC System

76
7th Auto-ID Lab

• April 1st, 2005
• ICU, South Korea accredited as the 7th Auto-ID Lab

77
The Auto-ID Laboratories
78
Laboratories research program

• Associate laboratories are contemplated
• 96 research topics (original six labs)
• 36 related to propagation and chip design
• 27 related to networking and software
• 35 related to business applications, privacy and
  security
• Korean lab interested in mobile sensor networks

79
EPCglobal network outline

• Discovery services
• ONS discovery service
• Discovery services for events
• EPC information services
• Enables users to securely exchange information
  with trading partners

• Electronic product code
• Formats for various applications
• ID system
• Tags and readers
• EPC middleware
• Replaces the savant
• ALE engine and interfaces
• Performs filtering a data routing for clients

80
EPCglobal structure
81
Membership (December 2004)
End Users
Solution Providers
End Users
Solution Providers
Total
Global
Total
Global
Europe
Asia
Austria
0
3
3
Australia
1
0
1
Denmark
1
1
2
Japan
7
14
21
Belgium
0
2
2
China
0
1
1
France
4
6
10
Singapore
2
2
4
Finland
0
2
2
Taiwan
0
9
9
Germany
11
12
23
India
1
6
7
Ireland
0
1
1
Hong Kong
0
17
17
Italy
0
2
2
New Zealand
1
0
1
Netherlands
2
2
4
Sth Korea
1
11
12
Russia
1
0
1
13
60
73
16.3


Spain
0
3
3
Middle East Africa
Sweden
2
0
2
Switzerland
2
0
2
Israel
0
1
1
UK
11
9
20
South Africa
0
2
2
34
42
76
17.0
0
3
3
0.7


Latin America
Brazil
1
1
2
Nth America
Colombia
1
0
1
Canada
2
6
8
2
0.7
1
3
US
138
148
286
140
154
294
65.5
449 members
82
Working Groups

• Business Steering Committee (BSC)
• Fast Moving Consumer Goods (FMCG)
• Healthcare and Life Sciences (HLS)
• Transport and Logistics (TLS)
• Technical Steering Committee (TSC)
• Hardware Action Group (HAG)
• Software Action Group (SAG)

83
FMCG Working Groups

• Data Exchange
• European Adoption Programme (EAP)
• Pilot and Implementation (PI)
• Reusable Transport Items (RTI)
• Strategic Planning
• Tag Data Standards (TDS) gt SAG
• Tag and Inlay Standards
• Asian Adoption Program (AAP)

84
HLS Working Groups

• Strategy
• Policy
• Process
• Information
• Technology
• Research

85
HAG Working Groups

• Class 1 Generation 2 (Work completed)
• Gen 2 Testing Certification
• Others planned

86
SAG Working Groups

• Reader Protocol
• Reader Management
• Filtering and Collection
• ONS
• Security
• Tag Data Translation
• EPCIS
• EPCIS Phase 2

87
EPCglobal network roles and interfaces
88
Standards Development Process
89
Transport Logistics (NEW)


90
Future Working Groups ?

• Automotive
• Aerospace
• Electronics
• Biologics

91
EPCglobal Conference

• http//www.epcglobalus.org/conference/

92

• PART 7
• CONCLUSIONS

Photo taken at Carlton United Beverages
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What to take away 1

• Simplicity of passive RFID for identity
• The weakness of the label reply
• Ubiquity of objects in supply chain
• Vision of the Auto-ID Center
• Electric and magnetic field concepts
• Source and vortex concepts
• Frequency wave length relation c fl

94
What to take away 2

• Near and far field concepts
• Radian sphere size and significance
• Boundary conditions near metal
• Behaviour of simple antennas
• Varieties of fast reading protocol
• Transformation of Center
• Auto-ID Labs research

95
What to take away 3

• EPCglobal networking concepts
• Standardised EPC
• Standardised readers, tags and protocols
• Standardised communication between roles

96

• Thank you

97

• EXCISIONS

98
The complete laws 1
Faraday's law The circulation of the electric
field vector E around a closed contour is equal
to minus the time rate of change of magnetic flux
through a surface bounded by that contour, the
positive direction of the surface being related
to the positive direction of the contour by the
right hand rule. Ampere's law as modified by
Maxwell The circulation of the magnetic field
vector H around a closed contour is equal to the
sum of the conduction current and the
displacement current passing through a surface
bounded by that contour, with again the right
hand rule relating the senses of the contour and
the surface.
99
The complete laws 2
Gauss' law for the electric flux The total
electric flux (defined in terms of the D vector)
emerging from a closed surface is equal to the
total conduction charge contained within the
volume bounded by that surface. Gauss' Law for
the magnetic flux The total magnetic flux
(defined in terms of the B vector) emerging from
any closed surface is zero.