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RFID

^{^{Flickr Free Image: RFID}}
[Please click the image to watch Avril Lavigne's "Here's to Never Growing Up"]

If you have visited a city called Warri in Nigeria, you would have heard the phrase, "You go old". It means you will grow old which is a good thing, right? Wrong! It means that you will get old while waiting for something to happen. Most of us are growing old while waiting on long checkout lines at grocery stores. It is expected that soon these lines could disappear when the famous Universal Product Code (UPC) barcodes are replaced by smart labels, also called radio frequency identification (RFID) tags.

^{Wikipedia Creative Commons: RFID Microcip Compared with a Grain of Rice}

RFID tags are intelligent bar codes that can communicate through a networked system to track every product that a buyer put in their shopping cart.

With the implementation of the RFID tags in grocery and other retail shops, customers could fill up their carts with RFID tagged items and walk right of the shops with the items; no queues, no waiting.

^{^{Pixabay Creative Commons}}

The (passive) RFID tags will communicate with the electronic reader which will detect every item in the cart as they walk out of the shop and ring each piece up almost instantly. If this reader is connected to a network connecting the retailers and manufacturers, the retailers can be notified of the items bought, and they can inform the customer's bank so that the bill will be settled without any further involvement of the customer. The manufacturers can also monitor inventory and incorporate the rate of sales in their supply chain management. How cool would that be?

The RFID Technology

It appears that everything I write takes me back to electromagnetic (EM) waves. RFID technology is based on EM waves. The early types of RFID employed Inductively Coupled RFID tags and Capacitively Coupled RFID tags and these seem like a good place to begin a discussion of RFID.

Inductively Coupled RFID Tags

These tags were powered by a magnetic field generated by the RFID reader. As we know from electromagnetics, moving electric charges (current) has the ability to generate a magnetic field around the conductor and a magnetic field is able to cause a flow of current.

^{^{Wikipedia Die Freie Enzyklopadie: Inductive Coupling}}

This production of electric current by magnetism and the generation of magnetism by an electric current is called Electromagnetic Induction and is the basis of the operation of inductively coupled RFID. The electric current in the RFID reader is primarily used to generate a magnetic field which induces electric current in the tags enabling the reader to read data from them. These were complicated tags made up of wires and antennas with an associated cost of production which hampered widespread application.

Capacitively Coupled RFID

Due to the cost implications of the inductively coupled RFID, the capacitively coupled tags were created to lower the cost of the technology to enable them to be used as cheap disposable tags for merchandise and possibly as a replacement for UPCs. These used conductive carbon ink instead of the metal coils used in inductive coupled RFID to exchange data with the reader. The technology, first projected by Motorola, did not quite catch on and was abandoned for newer innovations.

These innovations can store up to 2000 bytes of data and are made of a microchip and antenna. Some of them have batteries and are usually enclosed in plastic, silicon or glass. Their mode of operation is similar, the type notwithstanding. Tags that use batteries to send data are called active and those that do not are called passive. In between are those that have batteries but do not use the battery power to transmit data and those are called semi-active

How RFID Works

Before RFID tags, there were RF tags which are similar in function as the RFID tags except for one major difference. RF tags help the receiver identify the presence of a tag, and that's it. It does not provide any information as per the identity of the item bearing the tag, in which case if the RF technology is applied in a shop Anti-theft alarm, it would go off if a person has one item in a cart that was not properly checked out. The problem of identifying which item is left to the shop attendant or someone else. The most popular of these RF tags was the acousto-magnetic tag which speed and ease of scan made them excellent for anti-theft applications.

^{^{Free Image from Nellis.af.mil: Electronic Surveillance System}}

The RFID reader has a transmitter and a receiver fitted in it. If the RFID tag is used to identify products in a shop, then each product must have a concealed or visible RFID "tag". In an anti-theft application, walking through the doorway without paying for an item having an RFID tag would cause an alarm to be set off. This happens because the transmitter in one of the doors is continually sending off radio waves which would be picked up by an active RFID tag. On intercepting this radio wave, a small current would be generated in the label, causing it to release its radio signal at a specific frequency. The receiver in the other door (forming part of the anti-theft system) would receive this signal and sound the alarm.

Of course, the described scenario above would not play out the same way if the buyer had paid for the item. This is because the checkout assistant passes the items through, a deactivating device deactivates the electronic components in the RF label, so they no longer pick up or transmit a signal when the customer walks through the gates, ensuring that the alarm does not go off.

The operation of RFID is the same no matter the type of tag. Every tag works as follows:

Data is stored within an RFID tag's microchip, and this data remains there.
The tag would have an antenna that "listens" for EM energy from a reader's antenna until a reader sends a transmission in the form of EM energy.
The tag would receive the communication and use the energy (or energy from batteries, for active tags) and sends radio waves back to the reader.
The reader would then pick up the radio waves from the tag and interprets the frequencies and the encoded message as meaningful data.

Challenges

An obvious challenge that the RFID industry is facing as regards ubiquitous application of the technology in many aspects of life is the cost implications. If the industry can reduce the costs to acceptable levels, this would result in a network of smart RFID devices that can be used to monitor the entire supply chain as mentioned at the beginning of this post.

Other challenges that result to impeding widespread RFID implementation especially in the retail industry are reliability issues of the technology, privacy issues, lack of standards, data integration issues, and employee reluctance to change old ways of doing work. While cost is often mentioned as a significant challenge, privacy issues are the most dominant challenge that needs to be addressed before RFID can go mainstream, especially in the retail sector. Due to the enormous data generated by an RFID system, data integration issues are also a major problem that must be addressed.^[6]

The US of RFID by the US government as security measures in passports to curb forgery has also raised concerns bordering on:

skimming(a situation where unauthorised persons may scan the e-passport without holder's knowledge) or;
eavesdropping (a case where a bystander can obtain details of the e-passport as it is being scanned by an official). On these issues, the Department of Homeland Security has assured Americans that the e-passport is perfectly safe.^[5]

Conclusion

RFID tags are an improvement over barcodes. They offer much more than barcodes because they have read and write capabilities and data on them can be changed and locked. RFID tags are finding many applications from tracking cattle to inventory and supply chain management. RFID tags are also used in tracking pets, vehicles, airline passengers, Alzheimer's patients. It may soon help retailers to track user preferences. RFID is also being used in transportation devices such as highway toll passcards and passenger chip-embedded passes.

In spite of the potential widespread application of RFID, cost, security and data integration challenges have reduced the speed of adoption of RFID especially in the retail sector. It is hoped that we shall find the solutions to these problems in the next few years and therefore enjoy the ease of shopping and life that RFID can afford.

Here is to never wait on queues!

References

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RFID - Here is to Never Having to Wait