Radio-frequency identification (RFID)

2.2 Explain wireless networking technologies

📘CompTIA A+ Core 1 (220-1201)

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Definition:
RFID stands for Radio-Frequency Identification. It is a wireless technology used to track, identify, and manage objects using radio waves. Unlike barcodes, RFID does not need a direct line of sight—this means the system can read RFID tags even if they are hidden inside objects, boxes, or behind walls.

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Components of RFID

There are three main parts of an RFID system:

1. RFID Tag (Transponder):
   • This is a small device attached to an object.
   • Contains data like a unique ID or product information.
   • Two main types:
     • Passive RFID: No internal power source. It gets power from the RFID reader’s radio waves. Shorter range, cheaper, common in IT asset tracking.
     • Active RFID: Has its own battery. Can transmit signals over longer distances. Used in environments where tracking moving assets over large areas is needed.
2. RFID Reader (Interrogator):
   • A device that sends radio waves to the tag and receives the signal back.
   • Reads the data stored in the tag.
   • Can be connected to a computer or network to process and log the information.
3. Antenna:
   • Part of both the tag and reader.
   • Helps send and receive radio signals between tags and readers.

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How RFID Works in IT Environments

1. Asset Tracking:
   • IT departments attach RFID tags to servers, laptops, and peripherals.
   • RFID readers can quickly scan a room to check which assets are present.
   • Example: Checking all laptops in a data center without opening each cabinet.
2. Inventory Management:
   • RFID can automatically track IT inventory as it moves in and out of storage.
   • Saves time compared to manually scanning barcodes.
3. Security Access:
   • RFID cards or fobs are used for controlled access to rooms or data centers.
   • The reader verifies the tag ID and grants or denies access.
4. Lifecycle Management:
   • IT can track the lifecycle of equipment: when it was purchased, used, serviced, or retired.
   • Helps in audits and compliance reporting.

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RFID vs Barcodes

Feature	RFID	Barcode
Line of Sight Needed	❌ No	✅ Yes
Can Read Multiple Items at Once	✅ Yes	❌ No
Data Storage	More (can store unique ID + info)	Limited (just ID)
Durability	High (tags can be embedded)	Low (can be damaged)
Cost	Higher	Lower

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Frequencies and Ranges

RFID uses different radio frequencies for different purposes:

1. Low-Frequency (LF):
   • Range: ~10 cm
   • Used for access control and asset tracking inside a room.
2. High-Frequency (HF):
   • Range: ~1 meter
   • Common for inventory management and library systems.
3. Ultra-High-Frequency (UHF):
   • Range: 3–10 meters or more
   • Used in large warehouses or data centers to track equipment automatically.

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Advantages of RFID in IT

• Fast and automatic scanning of many items at once.
• Can track assets in real time.
• Reduces human error compared to manual tracking.
• Can enhance security for sensitive IT areas.
• Works in environments where barcodes fail (dust, metal, or enclosed spaces).

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Things to Remember for the Exam

1. RFID is wireless identification using radio waves.
2. Three main parts: Tag, Reader, Antenna.
3. Tags can be passive (no battery) or active (with battery).
4. Used for: asset tracking, inventory management, IT security, lifecycle management.
5. Works without line of sight, unlike barcodes.
6. Frequencies: LF, HF, UHF — different ranges for different applications.