Wireless Networking Fundamentals

Wireless Networks

• A network is considered wireless if at least two terminals communicate via a wireless link.
• Wireless networks are an extension of wired networks.

Wireless vs Wired

• Wired networks:
  • Communication via cable
  • Signals propagate in one direction only
  • Signals received only by the destination
  • Easy to implement
  • Does not support mobility
  • Rigid and difficult to maintain
  • Expensive to deploy and expand
• Wireless networks:
  • Communication via radio waves
  • Signals spread in all directions
  • Signals received by the destination and all nodes in the wireless coverage area
  • Easy to maintain and expand
  • Less expensive deployment
  • Supports mobility

Benefits and Challenges of Wireless Networks

• Strong features:
  • Support mobility
  • Easy and fast deployment
  • Flexible and agile use
  • Easy and quick extension and maintenance
  • More cost-effective
• Challenges:
  • Security
  • Energy
  • Mobility issues (location, handover, mobile addressing, etc.)

Wireless Communication Medium

• Electromagnetic wave: a wave that propagates through electromagnetic fields
• Examples of wireless communication:
  • Home automation
  • Industrial automation
  • Sensor networks
  • Contactless payments
  • Access control

Wireless Local Area Networks (WLAN)

• Range: Medium (maximum 100 meters)
• Purpose: Connect machines that are moderately distanced via wireless links (at the building level)
• Standard: IEEE 802.11
• Technology: WiFi, HipeLan2 (Europe), etc.
• Example: A local network of a company connecting equipment via an access point

WLAN - WiFi

• 1997: Publication of the WiFi (Wireless Friendly) standard by WiFi Alliance
• WiFi is a set of wireless communication protocols
• Data rate: 5.5 Mbps, 11 Mbps (802.11.b), 54 Mbps (802.11.a, 802.11.g), 10 Gbps (high-speed)
• Frequency band: 2.4 GHz | 5 GHz
• Range: About 100 meters (300m)
• Standard: IEEE 802.11.x
• Evolution: .b, .a / g, .n / ac, ..., .ax, ...
• Security: WEP, WPA, WPA2, WPA3
• Architecture:
  • Infrastructure mode: connection via an access point
  • Ad-hoc mode: direct connection between devices

Bluetooth vs ZigBee vs NFC

• Bluetooth:
  • Technology: Wireless communication technology
  • Frequency Band: 2.4 GHz
  • Range: Short range, typically up to 100 meters
  • Data Rate: Medium data rate, up to multi-Mbps
  • Power Consumption: Moderate to high
  • Topology: Point-to-point, Star
  • Suitability for Large-Scale Networks: Limited (piconet)
  • Application Areas: Personal area networks, audio streaming, etc.
• ZigBee:
  • Technology: Wireless communication technology
  • Frequency Band: 2.4 GHz
  • Range: Medium range, typically up to 100 meters
  • Data Rate: Low to medium data rate, up to 250 Kbps
  • Power Consumption: Low
  • Topology: Mesh
  • Suitability for Large-Scale Networks: Good (Large networks)
• NFC:
  • Technology: Wireless communication technology
  • Frequency Band: 13.56 MHz
  • Range: Very short range, typically up to 10 centimeters
  • Data Rate: Low data rate, up to 424 Kbps
  • Power Consumption: Very Low
  • Topology: Point-to-point, peer-to-peer
  • Suitability for Large-Scale Networks: Not applicable