In this blog post, we will look at how radio waves have gone beyond traditional broadcasting and have become a part of our everyday lives through various technologies such as RFID and NFC.
When most people hear the word “radio,” they probably think of radio broadcasts or DMBs hosted by DJs. However, the word “radio” also refers to radio waves and communication technology, not just broadcasting. Radio waves are used in various technologies today and have become deeply ingrained in our daily lives. For example, when borrowing books from a library, you don’t need to scan the barcode of each book. You can simply stack several books on the self-checkout machine and they will be automatically recognized and the loan completed. Also, at toll booths, vehicles can pass through without stopping and pay the toll automatically, and on buses, transportation cards are used instead of tokens. All of this is thanks to radio waves, especially RFID (Radio Frequency Identification) technology. RFID is making our lives more convenient, and in this article, we will learn about RFID, a “radio” technology in our daily lives that we have often overlooked, and NFC, which has evolved from it.
First, let’s take a closer look at RFID. RFID is, simply put, giving objects that cannot speak a voice with a unique frequency that can convey brief information. Objects with this unique frequency can exchange information without direct contact with the terminal. For example, a transportation card can transmit the age group and card balance of the passenger to a transportation card terminal even if it is in a wallet or bag, and a student ID card can prove that the cardholder is a student at the library entrance even through a wallet. As such, RFID is deeply embedded in our daily lives without us knowing.
The working principle of RFID basically consists of a tag that acts as the object’s vocal cords, an antenna that acts as the ears that hear the voice and the mouth that issues commands, and a reader that understands what the object is saying. The important point here is that RFID communicates using radio waves of a fixed frequency, not sound. The operation process begins when a tag attached to or embedded in an object transmits radio waves of a specific frequency. This radio wave contains 96 bits of information, including the type of RFID device, the device’s unique number, and the information to be sent and received, and an antenna tuned to the correct frequency receives this radio wave. The information received is processed by the reader, and if necessary, the antenna sends out radio waves containing the information again to modify the information stored in the tag.
RFID is largely divided into active RFID and passive RFID according to the power supply method of the tag. Active RFID is a type of RFID that is directly powered by the tag and can continuously deliver information in a loud voice. Thanks to these features, Active RFID is used in applications that require relatively long-range communication, such as object location tracking and high-pass systems. In contrast, Passive RFID is an RFID technology that uses tags that are temporarily powered by induced currents from the terminal, and is mainly used in cards that do not require a power supply, such as public transportation cards and student IDs.
RFID is also divided into several types depending on the frequency band used. RFID using LF (Low Frequency) frequency is inexpensive, but the communication distance is very short and the information transmission speed is slow, so it is used for livestock management, etc. On the other hand, RFID using UHF (Ultra High Frequency) frequency has a long communication distance and fast information transmission speed, so it is used for high-speed race record measurement, etc. RFID using HF (High Frequency, 13.56MHz) frequency has not been widely used due to the lack of a balance between cost and performance, but its use has increased as NFC technology has developed in recent years.
Now, let’s learn about NFC. NFC is a more advanced technology that complements the limitations of RFID and has transformed short communication distances into high security. NFC technology allows people to exchange business cards or make payments just by bumping their phones together, and it also allows people to use their phones as a transportation card. NFC is different from RFID in that it enables mutual communication. RFID terminals only have the function of an antenna and a reader, and tags exist separately, but NFC devices have a tag, an antenna, and a reader combined. Thanks to this, NFC devices can not only read and transmit information from other tags, but they can also be read by other NFC devices. This is like the evolution of the beeper (RFID) into a cell phone (NFC) that can send and receive text messages.
However, there are still challenges to be solved before NFC can usher in the era of smartphones replacing wallets. One of them is “lack of security.” Even though NFC is a technology based on long-distance communication, and the communication is short-range and the information is encrypted, it is not 100% secure. For example, if a hacker uses an NFC device to scan people’s bags or pockets in a crowded subway, there is a possibility that a large amount of personal information will be leaked in an instant. For this reason, NFC is currently mainly used for transportation cards that do not incur large losses. However, major card companies such as PayPal, Visa, MasterCard, and American Express are investing to solve security issues, so it is expected that the era of smartphones replacing wallets will come in the near future.
It is important for us to understand and adapt to the rapidly changing flow of technology. While enjoying the convenience of RFID and NFC, it is necessary to recognize and prepare for the risks that exist behind them. If radio used to connect people through music, stories, and videos, now radio waves are connecting people, machines, and things to make our lives more convenient and smarter.
