NFC protocol

- Oct 10, 2018-

NFC protocol

Near field communication is called NFC. This technology is similar to the RFID standard. We know that there are two types of fields around the RF antenna. Near field and far field. The near field refers to the electromagnetic radiation near the antenna (ie, the area reaching 2D 2 /λ), and the far field refers to the EM radiation away from the antenna. NFC has become very popular because short-range communication (several millimeters) has a very low data rate (several thousand bits per second). The NFC protocol is based on the RFID standard published and outlined in ISO/IEC 18092.

NFC is used in a variety of contactless applications, including access control for railways and offices, healthcare, information exchange, payments, and consumer electronics. NFC is basically a peer-to-peer communication method. It always requires initiators and goals. There are two types of communication based on power. In active communication, the initiator and target will alternately generate EM fields and communicate with each other. In passive mode, the target will receive power from the NFC reader. In passive mode, it is easy to make NFC targets using stickers and no battery is required.

NFC devices operate based on inductive coupling. Induction is the generation of current by passing a wire through a magnetic field (H). As far as we know, NFC devices have built-in coils. The magnetic field from the NFC device generates power in these coils, which initiates data transmission through the radio waves. Two devices (target and initiator) share this capability.

NFC technology has three modes of operation. They are readers, point-to-point and card emulation.

The reader/writer mode conforms to ISO/IEC 14443 and FeliCa specifications. In this mode, the NFC device can read the tag. The labels here are usually integrated into smart posters or stickers.

The peer-to-peer mode complies with the ISO/IEC 18092 standard. In this mode, the device is self-powered. The two devices communicate with each other and share information. Users of this mode can exchange Bluetooth or WLAN link setup parameters and exchange data, such as digital photos or virtual business cards.

In the card emulation mode, the data stored on the card is read by the NFC reader. A card with this mode is called a smart card and is used for various applications such as ticketing, payment, purchase, transfer access control mechanisms, and the like. In this mode, an NFC-compatible device communicates with the reader just like a smart card. This mode is two-way communication.

NFC frequency and data rate

NFC operates in the unlicensed ISM band of approximately 13.56 MHz. It supports data rates of 106 Kbps, 212 kbps and 424 Kbps. NFC uses a bandwidth of 14 KHz to map the data on the RF carrier. The sidebands of the NFC RF modulation spectrum can be extended to +/- 1.8MHz.

NFC application

NFC has a wide range of applications. Very few of them are outlined below. The following can be used with NFC phones and NFC smart cards.

• It is used for airport and rail passes, getting information from smart posters, getting information from kiosks, paying for bus or taxi fares.

• For vehicles to adjust seat position, open the door, pay parking fees, etc.

• For entry and exit locations in the office, exchange business cards, log in to the PC, print on a copier, etc.

• This is an NFC user using a credit card in this restaurant and so on. Figure 2 depicts the payouts in the NFC-compatible USIM, earning loyalty points, obtaining and using coupons, sharing information and coupons.

• Use the theater stadium at the entrance to get event information and more.

• It is used to download and personalize apps, check usage history, remotely lock phones, and more.

N-Mark is used for all NFC-compliant products. It is a global symbol for identifying and accepting NFC-compatible short-range wireless communication devices.