Overview
This lecture covers the basics of wireless networking standards, frequency usage, and mechanisms for optimizing wireless connections, focusing on standards like IEEE 802.11 and key wireless technologies.
Wireless Networking Standards
- The IEEE (Institute of Electrical and Electronics Engineers) 802.11 committee sets global standards for wireless networking.
- Older naming conventions like 802.11ac, 802.11ax, and 802.11b are now matched with simpler names: Wi-Fi 5, Wi-Fi 6, Wi-Fi 6E, and Wi-Fi 7.
- Future wireless standards will increment Wi-Fi numbers (e.g., Wi-Fi 8, Wi-Fi 9).
Frequency Bands and Channels
- 802.11 uses 2.4 GHz, 5 GHz, and 6 GHz frequency bands, often in combination.
- Frequencies are grouped into "channels" for easier reference (e.g., Channel 6 for 2.4 GHz centered at 2437 MHz).
- Wireless bandwidths commonly used are 20 MHz, 40 MHz, 80 MHz, and 160 MHz.
Spectrum and Channel Bandwidth
- The 2.4 GHz range offers three non-overlapping channels, typically using 20 MHz bandwidth each.
- The 5 GHz and 6 GHz ranges provide more available channels and variable bandwidth options.
- More frequency options in 6 GHz allow reduced interference and higher performance.
Device Compatibility and Band Steering
- Not all devices support all frequency bands; older devices may only use 2.4 GHz.
- Band steering allows administrators to direct devices to optimal frequency bands.
- Devices usually connect to the strongest signal, but this may not always provide the best throughput.
Regulation and International Standards
- Each country regulates its own wireless frequencies (e.g., FCC in the US).
- Global standards require international cooperation for interoperability and conflict reduction.
Wireless Interoperability Features
- 802.11h adds interoperability for networks to coexist in the same area.
- ITU (International Telecommunications Union) provides global wireless guidelines.
- DFS (Dynamic Frequency Selection) enables access points to auto-select conflict-free frequencies.
- TPC (Transmit Power Control) lets access points adjust device power to minimize interference.
Key Terms & Definitions
- IEEE 802.11 — The family of standards for wireless networking.
- Wi-Fi 5/6/6E/7 — Simplified public names for various 802.11 standards.
- Channel — A specific frequency range used for wireless communication.
- Bandwidth — The width of the frequency band used, measured in MHz.
- Band Steering — Technology for directing devices to optimal frequency bands.
- DFS (Dynamic Frequency Selection) — Auto-chooses frequencies to avoid conflicts.
- TPC (Transmit Power Control) — Allows adjusting device power for optimized communication.
Action Items / Next Steps
- Review bandwidth and channel allocation diagrams in course materials.
- Research your local country’s wireless frequency regulations.
- Read about the differences between Wi-Fi 5, 6, and 6E.