802.11 Wireless Networks and Bluetooth Overview

Frequency Bands

• 2.4 GHz Range
  • Used by many 802.11 standards.
  • Common channels: Channels 1, 6, and 11.
  • Each channel is 20 MHz, ranging from 2412 MHz to 2482 MHz.
  • Limited number of channels.
• 5 GHz Range
  • More channels available than 2.4 GHz.
  • Suitable for environments with many access points.
  • Allows for larger bandwidths: 20 MHz, 40 MHz, 80 MHz, up to 160 MHz.
  • 160 MHz Bandwidth: Utilizes two non-contiguous areas for communication.

Channel Allocation and Regulation

• Channels assigned by IEEE with designated numbers for easy reference.
• Multiple access points should operate on different channels to reduce interference.
• Regulations vary by country, managed by governmental agencies.
• Regulations dictate frequency usage, power levels, and interference limits.

Bluetooth Networks

• Operates in the 2.4 GHz ISM (Industrial, Scientific, and Medical) band.
• Personal Area Network:
  • Short-range communication, typically up to 10 meters.
  • Connects peripherals like headsets, keyboards, and speakers to mobile devices.
• Industrial Bluetooth: Additional standards allow for communication distances over 100 meters.
• Uses unlicensed part of the 2.4 GHz band, accessible without special government licenses.

Summary

• 2.4 GHz has limited channels, overcrowded in areas with many networks.
• 5 GHz offers more channels and bandwidth options, reducing interference and improving throughput.
• Bluetooth complements 802.11 by enabling wireless connectivity for personal devices, using the widely accessible ISM band.