Physical Object Tagging
and Decoding
Amnon Dekel
Embedded Computing Seminar
Fall 2005
Prof. Scott Kirkpatrick
Outline
•
•
•
•
•
Introduction
Object Tagging Methods
Object ID Acquisition in the Field
Data Entry in the Field
Some Applications
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Introduction
• Tagging
– The act of creating a linkage between a
physical object and a symbolic representation
of that object
Physical
Object
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Tag
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Symbolic
representation
3
Introduction
• Why Tag?
– Because the “Brave new world” of
Ubiquitous/Pervasive computing needs a way
to identify the world and what is happening in
it
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Introduction
• Why Tag?
– Enable Context discovery
– Enable Categorization
– Minimize errors
– Minimize ambiguity
– Enable linkages between objects
• Physical to physical
• Physical to symbolic (services)
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Introduction
• Why Tag?
– Context discovery
•
•
•
•
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Location (physical and symbolic)
Task (where in the process, service management)
Change (relative to planned)
Behavior Patterns (learn, react)
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Object Tagging
Object Tagging
• Two main methods
– Passive Tags
– Active Tags
Note: I use a slightly different meaning than the
existing Active/Passive
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Passive Visual Tags
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Passive Visual Tags
• Passive Visual Code Tags: Many Types
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Passive Visual Tags
• Passive Tagging:
– “Dumb” Tags which do not react to their
surroundings
– Stick and Forget
– Very Cheap
– Need Line of Site
– Range
• Normal use: Up to ~1.5 M
• Range can grow by enlarging the tag
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Passive Visual Tags
• 1 D Bar Codes:
– Provide a simple and inexpensive method of encoding
information that is easily read by inexpensive electronic
readers.
– Allows data to be collected rapidly and with extreme
accuracy.
– Consists of a series of parallel, adjacent bars and spaces.
– Predefined bar and space patterns or "symbologies" are
used to encode small strings of character data into a
printed symbol.
– Can be thought of as a printed type of the Morse code
with narrow bars (and spaces) -> dots, and wide bars ->
dashes
http://www.taltech.com/TALtech_web/resources/intro_to_bc/bcbascs.htm
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Passive Visual Tags
• 1 D Bar Codes:
– The different symbologies have different capabilities for
encoding data. For example the
• UPC symbology used to identify retail products always contains
12 numeric digits
• The general purpose Code 39 or Code 128 bar code
symbologies can encode variable length alphanumeric data up
to about 30 characters in length. These types of bar codes are
called "linear symbologies" because they are made up of a
series of lines of different widths.
– Most commercially available bar code scanners are able
to read all of the different linear bar code symbologies
therefore you do not need different readers for different
types of bar codes.
http://www.taltech.com/TALtech_web/resources/intro_to_bc/bcbascs.htm
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Passive Visual Tags
• 1 D Bar Codes:
12 Digits 
30 Chars 
http://www.taltech.com/TALtech_web/resources/intro_to_bc/bcbascs.htm
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Passive Visual Tags
1 D Bar Code Usage
Code Standard
Uses
UPC (Universal Product Code)
Retail stores for sales checkout; inventory, etc.
Code 39
Identification, inventory, and tracking shipments
POSTNET
Encoding zip codes on U.S. mail
European Article Number (EAN)
A superset of the UPC that allows extra digits for country identification
Japanese Article Number (JAN)
Similar to the EAN, used in Japan
Bookland
Based on ISBN numbers and used on book covers
ISSN bar code
Based on ISSN numbers, used on periodicals outside the U.S.
Code 128
Used in preference to Code 39 because it is more compact
Interleaved 2 of 5
Used in the shipping and warehouse industries
Codabar
Used by Federal Express, in libraries, and blood banks
MICR (Magnetic Ink Character
Recognition)
A special font used for the numbers on the bottom of bank checks
OCR-A
The optical character recognition format used on book covers for the human readable
version of the ISBN number
OCR-B
Used for human readable version of the UPC, EAN, JAN, Bookland, and ISSN bar codes
and for optional human-readable digits with Code 39 and Interleaved 2 of 5 symbols
See: http://searchcio.techtarget.com/sDefinition/0,,sid19_gci213536,00.html
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Passive Visual Tags
• 1D Barcode History:
– 1948: Woodland and Silver build prototype system
• Used ink and 500 watt light
– 1952: US Patent 2,612,994
– 1966: First commercial product
• The National Association of Food Chains (NAFC) put out a call to
equipment manufacturers for systems that would speed the
checkout process
–
–
–
–
–
–
1967: RCA installs reader in Cincinnati – standards needed
1970: Logicon: UGPIC standard, Sylvania Railroad Car scanning
1973: UPC standard
1974: First UPC scanner (NCR), first checkout: Packet of gum
1981: LOGMARS (Code 39) for the DoD
1984: Barcodes are mandated by Wal-Mart (remind you of
something?)
http://www.barcoding.com/Information/barcode_history.shtml
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Passive Visual Tags
• 2D Bar Codes: use 2 dimensions to get more
storage capacity
http://www.taltech.com/TALtech_web/resources/intro_to_bc/bcbascs.htm
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Passive Visual Tags
• 2D Bar Codes: use 2 dimensions to get more
storage capacity
– New "2-Dimensional" bar code symbologies like PDF417,
Aztec Code, Data Matrix and QR Code are also now
available that can encode several thousand bytes of data in a
single bar code symbol including text or binary data.
– The newer 2D bar code symbologies typically require special
bar code readers that are designed specifically for reading
them.
http://www.taltech.com/TALtech_web/resources/intro_to_bc/bcbascs.htm
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Passive Visual Tags
• The 2D “standards”:
– QR Code
– Data Matrix
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Passive Visual Tags
• QR Code
– 1994: Released by Denso wave
– The specification is disclosed and the
patent right owned by denso wave isn’t
exercised.
– Has been approved by various
standards bodies over the years,
• i.e. approved iso standard (ISO/IEC18004)
and available for purchase in their store
http://www.engadgeted.net/archives/2005/09/18/matrix-codes-visual-code-recognition-on-cellphones/
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Passive Visual Tags
• QR Code
– Uses three position detection patterns located
at corners of the symbol
– a data area and a quiet zone outside of the
symbol.
– The symbol size ranges from 21×21 to 177×177
modules (increases in steps of 4 modules per
side)
– it supports four error correction levels using
Reed-Solomon code.
– QR codes can store up to 7089 numeric
characters, 4296 alphanumeric characters or
2953 bytes
Position detection
http://www.engadgeted.net/archives/2005/09/18/matrix-codes-visual-code-recognition-on-cellphones/
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Passive Visual Tags
• QR Code
– 40 versions
Version
1
40
Modules
ECC Level
Data bits
Numeric
Alfanumeric
Binary
Kanji
7%
152
41
25
17
10
* 15%
128
34
20
14
8
25%
104
27
16
11
7
30%
72
17
10
7
4
7%
23,648
7,089
4,296
2,953
1,817
* 15%
18,672
5,596
3,391
2,331
1,435
25%
13,328
3,993
2,420
1,663
1,024
30%
10,208
3,057
1,852
1,273
784
21x21
177x177
http://www.denso-wave.com/qrcode/qrgene2-e.html
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Passive Visual Tags
• Micro QR Code
– Micro qr code sacrifices
storage capacity (35 Num,
21 ANum, 15 Binary) for a
smaller print footprint.
– It has only one position
detection pattern,
– supports fewer levels of
error correction
– ranges in symbol size
from 11×11 to 17×17
modules.
http://www.denso-wave.com/qrcode/microqr-e.html
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Passive Visual Tags
• Data Matrix Code:
– Invented by RVSI Acuity Cimatrix
– Has been placed in the public domain
– Is an approved iso standard
(ISO/IEC16022) and available for
purchase in their store
http://www.engadgeted.net/archives/2005/09/18/matrix-codes-visual-code-recognition-on-cellphones/
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Passive Visual Tags
• Data Matrix Code:
– Uses two solid borders as handles for alignment
– Two broken borders on the opposite corner as
syncs for module sampling
– Uses a data area and a quiet zone outside of the
symbol.
– Additional handles and borders are added with growing
matrix dimensions. (size ranges from 10×10 to
144×144)
– Supports Reed-Solomon error correction.
– Can store up to 3116 numeric chars, 2335
alphanumeric chars or 1555 bytes.
http://www.engadgeted.net/archives/2005/09/18/matrix-codes-visual-code-recognition-on-cellphones/
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Passive Visual Tags
• Additional 2D codes
Multi-Colored Matrix
Maxi (UPS) Code
Circular bar-codes
Info Density is not clear, but
Supposedly large
93 Alphanumeric chars
138 Numeric chars
No Data Available
PDF417
Aztec
3000 chars
3750 digits
2725 chars
More Info: http://www.taltech.com/TALtech_web/resources/intro_to_bc/bcsymbol.htm
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Active Tags
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Active Tags
• Active Tagging is the use of objects that can
respond to electromagnetic pulses and return
data to a query system
– RFID
• Passive
• Active
• NFC
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Active Tags
• RFID
Chip
Antenna
Radio Frequency IDentification
– An RFID tag is a small object that
can be attached to or incorporated
into a product, animal, or person.
– RFID tags contain silicon chips and An EPC RFID tag used for Wal-Mart
antennas to enable them to receive
and respond to radio-frequency
queries from an RFID transceiver.
– Passive tags require no internal
power source, whereas active tags
require a power source.
– IMPORTANT: No need for Line of Sight Communication!
http://en.wikipedia.org/wiki/Rfid
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Active Tags
• RFID History
– 1939: Watson-Watt: IFF (identification Friend of Foe) for RADAR
– 1948: Stockman, H. Communication by Means of Reflected Power.
Proceedings of the IRE, pp 1196-1204, October 1948.
– 1973: first Patents:
• Active tag with rewritable memory
• Passive transponder used to unlock a door without a key
– Mid 1980s: First Industrial Systems:
• Active System for tracking Dangerous materials
• Passive RFID system (125 kHz radio waves) to track cows
– Since:
•
•
•
•
Move up the spectrum to the unregulated 13.56MHz wavelength and above
Greater range, capacity and data transfer rates (IBM UHF RFID Patents)
Access control, anti-theft, smart cards…
1999: Auto-ID Center set up at MIT  RFID into the supply chain (simple ID
on chip is used to access information online) ->move the data Off the chip
(and thus make it cheaper).
– The grail: the 1cent tag
http://en.wikipedia.org/wiki/Rfid
http://www.rfidjournal.com/article/articleview/1338/1/129/
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Active Tags
• RFID Frequencies
cars
From: FDIS 2004 presentation: Prospects for RFID Technologies
More Info: The RFID Handbook
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Active Tags
• RFID Frequencies
From: http://www.rfid-handbook.de/rfid/frequencies.html
More Info: The RFID Handbook
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Active Tags
• RFID Frequencies
– Each frequency range has its advantages and
disadvantages.
• Europe use 868 MHz. for its UHF applications while the US
uses 915 MHz. for its UHF applications.
• Japan does not allow the use of the UHF frequency for RFID
applications.
• Low Frequency tags (LF) are less costly to manufacturer
than Ultra High Frequency (UHF) tags.
• UHF tags offer better read/write range and can transfer data
faster then other tags.
• HF tags work best at close range but are more effective at
penetrating non-metal objects especially objects with high
water content.
Source: http://www.controlelectric.com/RFID/Types_of_RFID.html
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Active Tags
• Interference?
– EPC standard UHF tags operate in the 850-950 MHz
frequency band. There is an interference with 802.xx
wireless LAN standards.
– Older WAN standards operating in the 915 MHz band
can cause interference and may have to be replaced
as interference can occur.
– Effective site surveys are required prior to the
implementation of RFID equipment to understand the
current radio frequency environment of the location
you wish to install RFID technology.
http://www2.cio.com/ask%5Cexpert/2004/questions/question1910.html
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Active Tags
• RFID Identification Speed:
– ISO 18000-3 Mode 2:
• 200 static Items/sec (theoretic speed)
• Magellan has shown a demo of 100 items/sec.
– ISO 18000-3 Mode 5:
• 500 static Items/sec (not implemented because of
prohibitive equipment costs)
From: http://www.teco.edu/~krohn/collaborative.pdf
Also: Magellan: http://www.rfidjournal.com/article/articleview/445/1/1/.
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Active Tags
• RFID Reader Costs
– Industrial readers cost
in the order of $2,0006,000, but small scale
systems are starting to
arrive:
• Home systems: $450
(iAutomate)
• Compact Flash Reader:
$150 (Syscan)
• Phidget RFID Reader:
$60 (Phidget)
• Press Release: $20
Reader (View)
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Active Tags
• NFC: Near Field Communications
– A standards-based, short-range wireless connectivity
technology that enables simple and safe two-way
interactions among electronic devices, allowing
consumers to perform contact-less transactions,
access digital content and connect devices with a
single touch
See: http://www.semiconductors.philips.com/news/content/file_1053.html
Near Field Communication Interface and Protocol -2
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Active Tags
• NFC: Near Field Communications
– NFC technology evolved from a combination of RFID and
interconnection technologies.
– Passive RFID Tags inside Nokia Phones (3300, 3500, 6360)
– NFC operates in the 13.56 MHz frequency range, over a
distance of typically a few centimeters.
– NFC technology is standardized in ISO 18092, ECMA 340, and
ETSI TS 102 190.
– NFC is also compatible to the broadly established contactless
smart card infrastructure based on ISO 14443 A, i.e. Philips
MIFARE® technology, as well as Sony’s FeliCa™ card.
– March 2004: Nokia, Philips and Sony establish the Near Field
Communication (NFC) Forum
See: http://www.semiconductors.philips.com/news/content/file_1053.html
Near Field Communication Interface and Protocol -2
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Active Tags
• NFC: Interference?
Standard: ECMA-352:1st Edition / December 2003
– OPERATING FREQUENCY (fc)
• 13.56 MHZ +/- 7 kHz.
– 6 External RF field threshold value
• NFCIP-2 devices shall detect external RF fields at the OPERATING
FREQUENCY with a value higher than HTHRESHOLD while
performing external RF field detection.
• The value of HTHRESHOLD = 0,1875 A/m.
– 7 RF Field detection
• In order to not disturb any communication on the OPERATING
FREQUENCY, an NFCIP-2 device shall not switch on its RF field
when it detects an external RF field, as specified in Clause 6.
Near Field Communication Interface and Protocol -2
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Object ID Acquisition
Object ID Acquisition
• Now that the information is in the world,
How do we access it?
– Passive Tags:
• Single Purpose Scanners
• Multi-Purpose Visual Recognition Systems
click
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Object ID Acquisition
• Now that the information is in the world, How
do we access it?
– Active Tags:
• RFID Readers
• Near Field Communications (NFC)
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Data Entry in the Field
Data Entry in the Field
• So the world is tagged and we can access
those tags and use them in a variety of
ways.
• The missing piece for a full cycle is to
enable data entry in the field
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Data Entry in the Field
• Why?
– Enable commercial transactions
• Which drives e-commerce in the field
– Enable bi-directional content services
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Data Entry in the Field
• Transactions:
– On board application uses ObjectID to carry
out a transaction (Buy, Rent, etc)
• NFC:
– Swipe your phone to the object (decode ObjectID)
– Send Transaction data commerce server (with ObjectID)
– Commerce Server notifies in store security system
• Visual Tags:
– Capture and decode ObjectID
– Send Transaction data commerce server (with ObjectID)
– Commerce Server notifies in store security system *
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Data Entry in the Field
Commerce Server
3. Notify
2. Transaction
In Store
Security
1. NFC ObjectID transfer
1. Visual ObjectID Decoding
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Data Entry in the Field
• Bi-Direction Content Services:
– On board application uses ObjectID to enable you to
communicate with a content service.
•
•
•
•
Get product information
Compare products
Collaborative Filtering
Personal Annotation
– Up-channel Technique:
•
•
•
•
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“Keying”: Click on Links or Text entry (Yuck!)
Send ObjectID query
Capture and Upload (Voice, Photo, Video)
Visual Gesture recognition (gesture represent simple
responses- i.e. Yes, No…)
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Applications
Applications
• Visual Tags
• Active Tags
– 1D:
• Item Number
• Manufacturer
• i.e. ISBN
– 2D:
• Web URL
• Object Information
• Gaming
• Rich location
information
• Physical Address
• Orientation Information
• Active Advertising
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– Supply Chain Management
– Real Time Location
Tracking
– Access Control
– People Tracking
– Baggage tracking
– Parcel Tracking
– Cloths Labels
– Animals
– Vehicle ID
– Electronic Locks
– Patients
– Communication ID’s
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Applications
• Demo1 : Visual Tags
• Demo2 : NFC
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Scenarios of Interest (to me)
• Shopping
• Moving Personal Media
… and how Tagging Technologies can be
used to help me Browse and Annotate the
world
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Shopping
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Shopping
Information Overload!
I can’t remember
what I want!
So many options!
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Shopping
• What can I do? I can use:
– A piece of paper
– Call my partner
– Remember by heart
– Or…
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Shopping
• Have my (Smart) Phone help me
• Remind me
• Give me more info on a product
• Tell me what others think of a product
• Suggest things to me (collaborative
filtering)
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Shopping
• Have my (Smart) Phone help me
– Give me more info on a product
• Visual decoding or NFC technology directs me to a
product information page
– Tell me what others think of a product
• Visual decoding or NFC technology directs me
to a product opinion page
– Suggest things to me (collaborative filtering)
• Visual decoding or NFC technology directs me to a
product suggestion page (People who bought this
also…)
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Moving Personal Media
• Now that our cell phones are rapidly
becoming our cameras and recorders,
how can we use Tagging technology to
enable them to become more integrated
into our media environment?
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Moving Personal Media
• What do we want to move?
– Our Media
• Photos
• Audio (personal recordings, music)
• Video
– Our Data
– Our Location
– Our Point of View
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Moving Personal Media
• Moving our media is relatively easy, isn’t
it?
– Install software on PC
– Install cable, or
– open wireless port
– Start communication session
– Move or Synch data
–…
• Too many steps, too complicated, too
many points of failure and actual failure
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Moving Personal Media
• Using Wireless data networking along with object
recognition we can make this as easy as point and
click:
– Point at the object you want to transfer your media to
– Click
• Your Camera-Phone decodes the ID of the object
• The ID is translated to an address online
• Your Camera-Phone transfers the media to the object over the
net
• Voila: your media is now shown on the device (TV, Computer,
iPod, etc)
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Moving Personal Media
I want to move my photo to my TV
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Moving Personal Media
I Zap my TV (with my camera or my NFC app)
Xxxxx
Xxxxx
Xxxxx
Capture and decode ObjectID
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Moving Personal Media
I Zap my TV (with my camera or my NFC app)
122.345.234.345.678.112
Capture and decode ObjectID
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Moving Personal Media
I send my photo to my TV
Send Photo to my TV
122.345.234.345.678.112
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Moving Personal Media
Enjoy!
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Moving Personal Media
Yes- I knowthe architecture could be designed to be
very different
i.e. direct communication
between the devices, etc…
But the concept remains the same
1. Capture code 2.Decode Address 3.Transfer
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Summary
Summary
• Two main forms of Object tagging
– Passive Tags (Visual Codes)
• Cheap
• Needs line of sight
(Most probably a transitional technology except in a few specific
cases)
– Active Tags (Electromagnetic Transfer)
• Getting cheaper (2004 ~$0.30 in large volumes)
• No need for line of site
• Starting to be integrated into consumer devices
(NFC)
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Summary
• Object Tagging will have a big effect on
our future
– (including our privacy, or lack of it)
– Many possible applications
– Big potential:
• Connecting the physical world with rich information
resources of the online world
• Enabling the ease of Ecommerce in the physical
world
• Adding the gigantic physical world market to the
Online Ecommerce ecosystem
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Summary
• Problems that still need to be overcome:
– Tag manufacturing costs still too high
• Goal: 1 cent RFID tags in volume (~2007)
– Conflicting and interfering systems
– Integration of NFC (or similar) technology in a
ubiquitous fashion
– Privacy concerns
– Culture
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Questions
• Amnon Dekel
amnoid at cs dot huji dot ac dot il
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