Near field communication (NFC)
- Abhishek
- Dec 23, 2017
- 4 min read
NFC stands for “Near Field Communication” . As its says for itself, it enables communication between devices supporting NFC over a short range.
As any other type of wireless communication it also requires one transmitting device, and another device to receive the signal.
TYPES OF NFC DEVICES
A range of devices at the global level uses NFC standards and based on how they work, can be classified as Active or Passive.
Passive NFC devices
Passive NFC devices can send information to other NFC devices without the need for a power source of their own.However they can't read or process the information sent by the other NFC devices.
Or simply we can say that a passive NFC device contains information that other devices can read but they cannot read any information sent by any other NFC devices.
e.g- NFC tags
NFC TAGS
A near field communication tag (NFC tag) is a sticker or wristband with small microchips that can be read by in range active devices. Information is stored in these microchips. A NFC tag has the ability to send data to other active NFC devices.
There are 4 types of NFC tags:-
Tag 1 Type: The Tag 1 Type is based on the ISO14443A standard. These NFC tags are read and re-write capable and users can configure the tag to become read-only. Memory availability is 96 bytes which is more than sufficient to store a website URL or other small amount of data.However the memory size is expandable up to 2 kbyte. The communication speed of this NFC tag is 106 kbit/s. As a result of its simplicity this tag type is cost effective and ideal for many NFC applications.
Tag 2 Type: The NFC Tag 2 Type is also based on ISO14443A. These NFC tags are read and re-write capable and users can configure the tag to become read-only. The basic memory size of this tag type is only 48 bytes although this can be expanded to 2 kbyte. Again the communication speed is 106 kbit/s.
Tag 3 Type: The NFC Tag 3 Type is based on the Sony FeliCa system. It currently has a 2 kbyte memory capacity and the data communications speed is 212 kbit/s. Accordingly this NFC tag type is more applicable for more complex applications, although there is a higher cost per tag.
Tag 4 Type: The NFC Tag 4 Type is defined to be compatible with ISO14443A and B standards. These NFC tags are pre-configured at manufacture and they can be either read / re-writable, or read-only. The memory capacity can be up to 32 kbytes and the communication speed is between 106 kbit/s and 424 kbit/s.
Active NFC devices
Active NFC devices are able to both send and receive data, and can communicate with each other as well as with passive devices.
e.g- Smartphones
Active NFC devices like Smartphones would not only be able to collect information from NFC tags, but it would also be able to exchange information with other compatible phones or devices and could even alter the information on the NFC tag if authorized to make such changes.
MODES IN WHICH AN ACTIVE NFC DEVICE CAN WORK
NFC card emulation—enables NFC-enabled devices such as smartphones to act like smart cards, allowing users to perform transactions such as payment or ticketing.
NFC reader/writer—enables NFC-enabled devices to read information stored on inexpensive NFC tags embedded in labels or smart posters.
NFC peer-to-peer—enables two NFC-enabled devices to communicate with each other to exchange information .
SO,HOW IT WORKS??
NFC works on the principle of sending information over radio waves.The technology used in NFC is based on older RFID (Radio-frequency identification) ideas, which uses electromagnetic induction in order to transmit information.A reader emits a small electric current which creates a magnetic field that in turn bridges the physical space between the devices. That field is received by a similar coil in the client device where it is turned back into electrical impulses to communicate data such as identification number status information or any other information.This is one of major difference between NFC and Bluetooth/WiFi, as it can be used to induce electric currents within passive components as well as just send data.And this is the way a passive NFC device like a NFC tag can power itself.
NFC works in the 13.56 MHz radio frequency spectrum using less than 15 mA of power for data transmission over really short distances.Data can be sent at either 106, 212 or 424 kilobits per second or 53 kilobytes per second which is enough for a range of data transfers.
There are three signalling modes in NFC referred as NFC-A, NFC-B and NFC-F. Explaining them is going to take a whole new article so if you are interested and want to know more about it you can click here.
ADVANTAGES OF NFC
The conclusion sticks to why we need to use NFC when we have technologies like bluetooth..
A little comparison-
Bluetooth connections can transmit data up to 10 meters or more easily, while NFC has a far less range of than bluetooth.
Even some older versions of bluetooth like Bluetooth 2.1 can transfer data at a speed of 2.1 Megabits/s far faster than NFC.
However the major point in favor of NFC is enough to declare NFC a winner at certain scenarios and that point is faster connectivity. Due to the use of inductive coupling, and the absence of manual pairing, it takes less than one tenth of a second to establish a connection between two devices and is super handy to use at certain scenarios like Mobile payment systems.
Apart from this one more point in it's favor is that it has much lower power consumption than Bluetooth which makes it perfect for passive devices such as advertising tags.
I hope you have a clear idea about the NFC technology after reading this post. If you have any questions feel free to ask me through the contact section of my website .
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