NFC stands for Near Field Communication. It enables short range communication between compatible devices. At least one transmitting device and another recieving device is needed to transmit the signal. Many devices can use the NFC standard and are considered either passive or active.
So NFC devices can be classified into 2 types:
- Passive NFC devices –
These include tags, and other small transmitters which can send information to other NFC devices without the need for a power source of their own. These devices don’t really process any information sent from other sources, and can not connect to other passive components. These often take the form of interactive signs on walls or advertisements.
- Active NFC devices –
These devices are able to both the things i.e. send and receive data. They can communicate with each other as well as with passive devices. Smartphones the best example of active NFC device. Card readers in public transport and touch payment terminals are also good examples of the technology.
How does NFC work?
Like other wireless signals Bluetooth and WiFi, NFC works on the principle of sending information over radio waves. Near Field Communication is another standard for wireless data transition which means devices must adhere to certain specifications in order to communicate with each other properly. The technology used in NFC is based on older technology which is the RFID (Radio-frequency identification) that used electromagnetic induction in order to transmit information.
This creates one major difference between NFC and Bluetooth/WiFi. NFC can be used to induce electric currents within passive components rather than just send data. This means that their own power supply is not required by passive devices. Instead they can be powered by the electromagnetic field produced by an active NFC component when it comes into range. NFC technology unfortunately does not command enough inductance to charge our smartphones, but QI charging is based on the same principle.
The transmission frequency is 13.56 megahertz for data across NFC. Data can be sent at either 106, 212, or 424 kilobits per second which is quick enough for a range of data transfers like contact details to swapping pictures and music.
The NFC standard currently has three distinct modes of operation to determine what sort of information will be exchanged between devices.
- The most common used in smartphones is the peer-to-peer mode. Exchange of various piece of information is allowed between 2 devices. In this mode both devices switch between active when sending data and passive when receiving.
- The second mode i.e. read/write mode is a one-way data transmission. The active device, possibly your smartphone, links up with another device in order to read information from it. NFC advertisement tags use this mode.
- The third mode of operation is card emulation. The NFC device can function as a smart or contactless credit card and make payments or tap into public transport systems.
Comparisons with Bluetooth –
There are several important technological differences between NFC and bluetooth but NFC has some significant benefits in certain circumstances.
The major advantage of NFC over bluetooth is that it requires much less power consumption than Bluetooth. This makes NFC perfect for passive devices, such as the advertising tags as they can operate without a major power source.
But this power saving does have some major drawbacks. First and the foremost is that the range of transmission of NFC is much shorter than Bluetooth which is a major drawback. NFC has a range of around 10 cm, just a few inches whereas Bluetooth connections can transmit data up to 10 meters or more from the source. Another drawback is that NFC is quite a bit slower than Bluetooth. NFC can transmit data at a maximum speed of just 424 kbit/s, whereas Bluetooth 2.1 can transmit 2.1 Mbit/s and with Bluetooth Low Energy around 1 Mbit/s .
NFC has one another major advantage i.e. faster connectivity. It uses inductive coupling(i.e. the absence of manual pairing) which takes less than one tenth of a second to establish a connection between two devices. While modern Bluetooth connects pretty fast, NFC is still super handy for certain scenarios as mobile payments.
Samsung Pay, Android Pay, and even Apple Pay use NFC technology though Samsung Pay works a bit differently than the others. While Bluetooth works better for connecting devices together for file transfers, sharing connections to speakers, and more, we anticipate that NFC will always have a place in this world thanks to mobile payments — a quickly expanding technology.
Attention reader! Don’t stop learning now. Get hold of all the important CS Theory concepts for SDE interviews with the CS Theory Course at a student-friendly price and become industry ready.