Wireless Networks Protocol (Wi-Fi)



  • Wireless fidelity
  • LAN Protocol
  • IEEE 802.11
  • Standards: a,b,g, and n
    • Frequency
    • Speed
  • Works in ISM band
  • Uses 2.4 GHz and 5GHz
  • Frequency band divided into channels
  • Governed by WiFi Alliance


802.11 Standard

  • WLAN standard
  • Uses air as transmission media
  • Concerned with the 2 lower layers of the OSI model
  • Data link layer
    • Logical link control (LLC)
    • Medium access control (MAC)
  • Physical layer
    • Physical layer convergence procedure (PLCP)
    • Physical medium dependent (PMD)


Infrastructure vs Ad-Hoc Modes

  • Infrastructure
    • Uses access point
    • Star topology
    • More commonly used
  • Ad-Hoc
    • Direct communication
    • Exists for short period
    • Suitable for meetings and conferences
    • More flexible in setup
    • Point-to-point



  • Service Set Identifier
  • Used to identify wireless LAN
  • Can be broadcasted or hidden
  • Length: 32 alphanumeric characters
  • Can be composed of several access points
  • Single access point can connect to several SSIDs



  • Carrier Sense Multiple Access Collision Avoidance
  • Uses request to send RTS and clear to send CTS to avoid collisions
  • Possibility of collision still exists
  • Lead to slower performance
  • Recovered by resending


Recommended Study Material
Learn on the go.
The app designed for the modern cyber security professional.
Get it on Google PlayGet it on the App Store
Practice Labs and Exam Vouchers

Congratulations! You're taking the first step to getting certified. Get some hands on experience with available practice labs OR save some money, support Cybrary, and purchase discounted exam vouchers. Ready to earn your next industry certification? Join cyber security's largest community and start learning today.


Our Revolution

We believe Cyber Security training should be free, for everyone, FOREVER. Everyone, everywhere, deserves the OPPORTUNITY to learn, begin and grow a career in this fascinating field. Therefore, Cybrary is a free community where people, companies and training come together to give everyone the ability to collaborate in an open source way that is revolutionizing the cyber security educational experience.

Cybrary On The Go

Get the Cybrary app for Android for online and offline viewing of our lessons.

Get it on Google Play

Support Cybrary

Donate Here to Get This Month's Donor Badge

Skip to toolbar

We recommend always using caution when following any link

Are you sure you want to continue?