A wireless signal is an electromagnetic signal transmitted through air or another unbounded medium. It radiates through open space rather than remaining inside a cable. section 18.1.1
Treat wireless transmission as a shared operational environment:
- All devices within sufficient range can receive the signal, increasing privacy concerns. section 18.1.1
- Devices contend for airtime and operate in half-duplex mode because simultaneous transmissions can collide. section 18.1.1
- Interference, regulatory requirements, and coverage area affect wireless communication. section 18.1.1
- Encryption protects information because nearby receivers can capture wireless signals, even inside a private LAN. section 20.1.1
Nearby interception
An unencrypted login transmitted over a wireless LAN can be overheard by an attacker within range; encryption converts the message into unintelligible ciphertext. section 20.1.1
Figure 18.2 Similar to how frames are flooded to all devices connected to a hub, all devices within range of a wireless device receive its signals.
Compare wireless reception within range with frame flooding across devices connected to an Ethernet hub. section 18.1.1
