2.3 Wireless Networking Standards and RFID Technology

Overview of Wireless Networking Standards

• Wireless networks are standard in homes and businesses.

• The IEEE 802 committee governs wireless networking standards, with the 802.11 standard specifically focusing on wireless networks.

• The term "WiFi" is frequently used as an abbreviation for 802.11 networks, trademarked by the WiFi Alliance.

802.11 Standards Timeline

1. 802.11a

   • Release Date: October 1999

   • Frequency Range: Operates in the 5 GHz band

   • Maximum Speed: 54 Mbps

   • Range: Limited range due to higher frequency absorption by objects

   • Current Usage: Rarely seen today as most have upgraded to newer standards.

2. 802.11b

   • Release Date: Concurrent with 802.11a

   • Frequency Range: Operates in the 2.4 GHz band

   • Maximum Speed: 11 Mbps

   • Advantages: Surfaces longer range due to frequency bouncing; common interference with other devices like baby monitors, Bluetooth, etc.

   • Current Usage: Difficult to find in operation; often replaced by newer standards.

3. 802.11g

   • Release Date: June 2003

   • Frequency Range: Operates in the 2.4 GHz band

   • Maximum Speed: 54 Mbps

   • Compatibility: Backward compatible with 802.11b.

   • Interference: Same issues with other devices as 802.11b.

4. 802.11n (WiFi 4)

   • Release Date: 2009

   • Frequency Range: Can operate on both 2.4 GHz and 5 GHz bands

   • Maximum Theoretical Throughput: 600 Mbps (using 4 streams with MIMO)

   • MIMO Support: Yes, allowing multiple signals to be sent simultaneously

   • Bandwidth Capacity: Supports wide channel widths of up to 40 MHz.

5. 802.11ac (WiFi 5)

   • Release Date: January 2014

   • Frequency Range: Exclusively operates in the 5 GHz band

   • Maximum Throughput: Nearly 7 Gbps across 8 streams with multi-user MIMO

   • Channel Bandwidth: Supports up to 160 MHz for greater data transfer.

6. 802.11ax (WiFi 6)

   • Release Date: February 2021

   • Frequency Range: Operates in both 5 GHz and 2.4 GHz

   • Maximum Theoretical Throughput: 9.6 Gbps

   • OFDMA: Introduces Orthogonal Frequency Division Multiple Access for more efficient communication in crowded areas.

Summary of Theoretical Throughput

• 802.11a: 54 Mbps (1 stream)

• 802.11b: 11 Mbps (1 stream)

• 802.11g: 54 Mbps (1 stream)

• 802.11n: 150 Mbps per stream, 600 Mbps maximum

• 802.11ac: 867 Mbps per stream, 6.9 Gbps maximum

• 802.11ax: 1.2 Gbps per stream, 9.6 Gbps maximum

Networking Considerations

• Range: Standard home access points typically provide coverage of about 40-50 meters.

• Directional Antennas: For long-range wireless connections, particularly between buildings, fixed directional antennas like YAGI may be required.

• Regulatory Compliance: When installing networks, be aware of local regulations regarding frequency usage and signal strength.

Other Wireless Technologies

• RFID (Radio Frequency Identification): Used for access cards, inventory tracking, and personal pet identification.

  • Types: Active (with power source) and passive (no battery, powered through energy capture).

• NFC (Near Field Communication): Facilitates two-way communication, such as mobile payment systems and device pairing.