NFC i.e. Near Field Communication is a way of communication between two electronic devices one among which is mostly a portable device such as smartphones. These devices can communicate with each other when brought within 4 cm of range. NFC is being used in various ways such as sharing photos, making mobile payments, getting information of posters etc. This process requires atleast one of the devices involved to have internet access.
The NFC device can work in three modes:
- NFC peer-to-peer
- NFC reader/writer mode
- NFC card emulation
In this both the devices are active devices that is both devices generates radio waves through which they communicate with each other. Only one device generates radio waves at a time and receiver connects to it and receives the shared files and when another device is active the first one does not generate the signals. The radio waves are generated at the carrier frequency of 13.56 Mhz.
In this one device is active and other device is passive. In this user access the information from the NFC tag using Smartphones. Active device reads/writes the data to NFC using the principle of electromagnetic induction. NFC device sends the radio waves at carrier frequency of 13.56 Mhz. Whenever the active device is brought withing the range it generates radio waves which are detected by the chip in passive device which in turn generates power for chip and activates it for transferring the information stored in it. Once the device is powered up the chip responds back by the technique known as Load Modulation. In this technique the tag uses internal clock of chip and generates auxiliary frequency of 848 khz.
NFC Card emulation:
This is similar to NFC reader/writer in which one device is portable such as smartphones and are mostly used for making mobile payments. Both the devices involved are active devices. In this our smartphone work as passive smart card, therefore do not generate radio waves and responds back to requested data by payment terminal. Its operating principle is similar to reader/writer mode.
Various Applications of NFC:
NFC is being used for profile sharing, pairing different devices, mobile payments, information sharing using smart posters and business cards, home automation, health care, library systems and personal usage etc.
Just by using NFC brightness of embient lights in room can be changed. It can be used for changing the temperature of the AC as well as in auto close doors.