2.2 Explain wireless networking technologies
📘CompTIA A+ Core 1 (220-1201)
NFC (Near Field Communication)
Definition:
NFC stands for Near Field Communication. It is a wireless communication technology that allows devices to exchange data over very short distances, usually 4 cm (about 1.5 inches) or less.
It is a subset of RFID (Radio Frequency Identification) technology but designed for two-way communication between devices, meaning both devices can send and receive information.
Key Features of NFC
- Short-range communication:
- Works only at very close distances. This makes it secure and controlled, because devices need to be practically touching to exchange data.
- Low speed and low power:
- NFC is not for big file transfers like videos. It’s mainly for small amounts of data—like authentication tokens, access keys, or contact information.
- Two-way communication:
- Unlike some wireless technologies that only send data one way (like RFID tags), NFC devices can both send and receive information.
- Works with existing devices:
- Many smartphones, laptops, and peripherals have NFC built in, so you don’t always need extra hardware.
Types of NFC Communication
NFC can operate in three modes:
- Reader/Writer Mode:
- One device reads or writes data to a passive NFC tag.
- Example in IT: Scanning an employee ID badge to log into a secure system.
- Peer-to-Peer Mode:
- Two NFC-enabled devices exchange information directly.
- Example in IT: Two smartphones sharing Wi-Fi network credentials or files with a tap.
- Card Emulation Mode:
- The device acts like a contactless card.
- Example in IT: A smartphone acting as a security badge to unlock doors or authorize printing jobs.
Common Uses of NFC in IT Environments
For CompTIA A+, you should know real IT-relevant examples of NFC:
- Secure Access Control:
- Employees tap NFC-enabled ID cards or smartphones to enter a building or room.
- IT systems read the NFC token and allow access based on permissions.
- Device Pairing:
- NFC can automatically pair devices with Bluetooth or Wi-Fi.
- Example: Tapping a laptop to a printer to instantly set up a connection.
- Authentication:
- Some IT systems use NFC for two-factor authentication (2FA).
- Example: Tapping an NFC security key to log in to a company portal.
- Data Exchange:
- Sharing small bits of information securely between devices.
- Example: IT support sharing Wi-Fi credentials with a mobile device using NFC.
Advantages of NFC
- Secure: Very short range makes it harder for hackers to intercept.
- Simple to use: Just tap the device—no complex setup.
- Convenient: Can replace physical cards or cables.
Limitations of NFC
- Short range: Needs close contact.
- Slow speed: Not suitable for large files.
- Limited support: Not all devices have NFC, especially older ones.
Important Exam Notes
- NFC is a wireless communication technology for very short distances.
- It supports three modes: reader/writer, peer-to-peer, card emulation.
- Common IT uses: secure access, authentication, device pairing, data exchange.
- It is secure due to short range, but slow and limited to small data transfers.
