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RFID Implementation Architecture for real
time scenarios
by Shilpa Reddy04-02-2007 |
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Article:
Radio Frequency Identification technology is all about identifying an object
through emitted radio ways. The technology revolves around 2 major components -
Tag and a Reader. Though RFID technology in theory is similar to bar code
technology, from an operation perspective it is different from bar code
technology. Unlike Bar code, RFID doesn't require Line of Sight reading while
Bar code requires. The transmission range of RFID even ranges for about more
than 90 ft depending on various Readers.
History:
To talk a little bit about history of RFID, it has been there for about 60
years now. This was first used by Britain to identify aircraft in World War II.
This has not become all that popular so far due to the associated cost factor
behind manufacturing Tags/Readers. From 1998 there has been a revolutionary
invention around creating tags that are cheaper and affordable to be
implemented.
RFID Implementation Components -
RFID Implementation can be done by adopting few key components. The key
components that form part of RFID implementation architecture are -
1. Tags -
a. What are Tags - Tags comprise of simple silicon chip with an aerial
mounted on a substrate. This aerial emits radio waves which will be read by the
reader. The Tag contains Unique Identification Number provided by EPC
(Electronic Product Code) and can also have other details depending on other
requirements.
b. Types of Tags - Active and Passive. Active tags themselves contain power
and they emit radio waves which reader reads. The Passive tags are those which
don't have power capability within them and hence depends on reader to send
power to the tag and retrieve information of the tag.
c. Classifications of Tags - Class 0 which is read only these can only
transmit EPC code to the reader, the other classification is Read/Write (complex
tags) which transmits the code to the reader and also the flags within it can be
modified based on response from Readers. There are few special made Tags which
destroy themselves after updating the code.
d. Printers - Printers print EPC code/other info on Tags. There are printers
like Zebra which print unique identification number on the tag.
2. Readers -
a. What are Readers? - Readers contain antennas that send and receive RF data
to and from Tags. A reader may have multiple antennas.
b. Various Vendors of Readers - The various Vendors that provide Readers are
Alien, Symbol RFID Solutions (Matrix) etc. These vendors provide Reader hardware
along with set of APIs to be used to read the tags.
3. RFID Engine - RFID Engine is the key component that reads tags, processes
those and outputs the tags info to the desired destinations. The two components
that form this RFID Engine are below -
a. Data Acquisition Engine - This can be designed/developed as a .net
component. This component consumes APIs provider by various Reader vendors. It
reads the Tag info, collects them one at a time or in bulk depending on the
scenarios configured and routes the tag (s) info to the next layer Data
Processing Engine through .Net Remoting.
b. Data Processing Engine - This can be designed/ developed as a .net
component. This component receives tag(s) info provided by Data Acquisition
Engine. This will contain rules configured for various scenarios. Depending on
the scenario, the respective rules will be applied on the received tags to
filter tags data. The output tag(s) after all the filtration will be flowed to
the desired output depending the architecture requirement.
Technical Architecture Proposal with various Scenarios -
I have explained the implementation of RFID in various real life scenarios
with the technical architecture below
1. Conveyor -
a. Architecture Diagram
b. Implementation Process
i. Shipments containing RFID tags will be placed on Conveyor belt
ii. At the end of the conveyor, RFID reader will be positioned.
iii. The operator (human) at the end of the conveyor belt, logs into the
system and opens Conveyor Web Application and clicks on the event start reading
iv. From WebApp, a trigger goes to the RFID engine layer. This layer on
receiving trigger for start event, send the start command to the Reader. The
Reader on the conveyer end has configurable flags to start/stop reading the tags
in its vicinity.
v. Data Acquisition uses the APIs provider by the reader. Through this API,
Data Acquisition engine retrieves EPC code of each of the Tags one by way. DAE
further forwards the EPC ID to the Data Processing Engine.
vi. Data Processing Engine, reads the tags and applies rule to check if the
ID is corrupted or filter if it is already being read. Once it passes this check
this id will be placed in MSMQueue. assed to Web App's method
vii. WebApp reads from the Queue and displays on the UI to the user info
about each shipment.
viii. Once all the shipments are through, WebApp send a Stop Reader trigger
to the RFID engine, which sends the Stop flag to reader. Reader on receving this
flag stops reading the tags anymore.
c. Pros/Cons
i. Pros: The following are the pros of using RFID in Conveyor -
1. Scanning of shipments will be faster as line of sight scanning is avoided.
2. Reduced manual operations
ii. Cons: The following are the cons of using RFID in Conveyor -
1. Equipment would be expensive relatively
2. Possibility of tags getting tampered and hence not being read. This can be
mitigated by ensuring quality of tags
2. Shelf
a. Architecture Diagram
b. Implementation Process
i. Goods containing RFID tags will be arranged on shelves
ii. RFID readers will be placed on shelves to read the tags.
iii. The type of configuration that is required for these kinds of readers,
are the readers should be configured to switch on and start reading on periodic
intervals for defined amount of time.
iv. In this scenario, when the radar switches on to start reading, the
various tags info will be collected in bulk in the data acquisition engine.
After collecting all the tag info, the collection of tags will be sent to Data
Processing Engine
v. Data Processing engine applies the following rules -
1. Since there is possibility of having multiple readers, a single tag can be
read by multiple readers, there by filtering should happen to pick only single
tag info.
2. Since the reader reads for defined amount of time, the same set of tags
can be read multiple times by the same reader. There by this filtration has to
be done to pick only once.
3. There is a possibility of bad data for some tags in the surroundings which
are not part of the shelves also to be read by the reader. These tags have to be
filtered out based on the initial no of the EPC code which signifies the reader,
purpose.
vi. Once the above rules are applied, the resultants set of tags information
can be dumped in the form of an xml into some shared location.
vii. A windows service can be written which keeps polling this shared drive
and once the file is found it can have the logic to process this info based on
the need.
c. Pros/Cons
Pros: The following are the pros of using RFID in Shelf -
1. Reduced manual operation to scan the goods to find out their status
2. Goods can be traced easily by the location of their reader by reducing the
pain of searching across the huge shelf.
3. Operator receives notification on periodic intervals about the goods.
Cons: The following are the cons of using RFID in Shelf -
1. Equipment would be expensive relatively due to the requirement of multiple
readers depending on volume of goods.
2. Possibility of tags getting tampered and hence not being read. This can be
ensured by ensuring quality of tags beforehand.
3. Logistics
a. Architecture Diagram
b. Implementation Process
i. Goods that are to be shipped to a different location will be having RFID
tags attached to them. These will be loaded in a truck.
ii. RFID readers can be located at regular check points between source and
destination.
iii. The reader at check points reads the tags in its vicinity and passes the
tag info to the Data Acquisition Engine. Data Acquisition Engine collects all
the tags info in bulk and then transmits those to the Data
Processing Engine.
iv. Data Processing Engine applies the following rules -
1. Since the reader read tags for defined amount of time, the same set of
tags can be read multiple times by the same reader. There by this filtration has
to be done to pick only once.
2. There is a possibility of bad data for some tags in the surroundings which
are not part of the carriage also to be read by the reader. These tags have to
be filtered out based on the initial no of the EPC code which signifies the
reader, purpose.
3. Since the tags will be exposed externally, various environment conditions
like rain, dust might affect in transmission of radio frequency waves resulting
in tags not being read by reader.
v. Once the above rules are applied, the resultants set of tags information
can be dumped in the form of an xml into some shared location.
vi. A service can be written which polls the shared location and whenever the
file is placed, reads the tags info from the file and sends a notification
(email) to the configured representative of the logistics organization.
c. Pros/Cons
Pros: The following are the pros of using RFID in Retail -
4. Shipments can be tracked easily unlike being clueless of shipments
although shipping process.
5. Loss of shipments can be identified early in the game.
6. Reduced manual operations
Cons: The following a re the cons of using RFID in Retail -
3. Equipment would be expensive relatively.
4. Possibility of tags getting tampered and hence not being read. This can be
mitigated by ensuring quality of tags beforehand
5. Environmental conditions might affect reading of tags.
4. Retail
a. Architecture Diagram
b. Implementation Process
i. Products in the retail store will be embedded with RFID tags. These will
be placed in shelves in the stores. The type of tags that can be used here will
be Read/Write tags.
1. Scenario 1: RFID readers at Cash Counter
a. At the Cash Counter once the payment process starts, a signal can be sent
to the Cash Counter reader through RFID Engine to start reading.
b. Once the Reader receives signal to start reading, it reads all the tags in
its vicinity and deactivates those. It then passes the tags info to the Data
Acquisition Engine. Data Acquisition Engine collects all the tags info in bulk
and then transmits those to the Data Processing Engine
c. Data Processing Engine applies the following rules -
i. Since the reader read tags for defined amount of time, the same set of
tags can be read multiple times by the same reader. There by this filtration has
to be done to pick only once.
ii. There is a possibility of bad data for some tags in the surroundings
which are not part of the collection also to be read by the reader. These tags
have to be filtered out based on the initial no of the EPC code which signifies
the reader, purpose.
d. Once the above rules are applied, the resultant set of tags information
will be sent to the web application through web service and displays the product
info on the UI
e. As an alternative to deactivating the Tag, after the tag is read in the
UI, it can be removed also.
2. Scenario 2: RFID Readers at Exit gate.
a. At the Exit gate, when the reader reads any tag, a voice signal can be
generated by configuring reader itself.
c. Pros/Cons
Pros: The following are the pros of using RFID in Retail -
7. Billing process will be faster as line of sight scan is not required for
products and all the products will be read instantly
8. Theft of products will be reduced
9. Reduced manual operations
Cons: The following are the cons of using RFID in Retail -
6. Equipment would be expensive relatively.
7. Possibility of tags getting tampered and hence not being read.
Conclusion -
As the RFID technology is being refined on an ongoing basis, by inventing
light weight and low cost tags and readers, the adoption of it in various real
life scenarios will become increasingly more. RFID is a revolutionary technology
to influence the current state and various functions are planning to adopt it to
improve their process.
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