Where does 802.11 fit in the IP Network Model?
802.11 is a set of data link and physical layer protocols.
Data Link Layer (MAC):
Responsible for reliable link-to-link data transfer.
- Channel access (CSMA/CA)
- Addressing
- Frame validation (management, data, control frames)
- Error detection
- Security mechanisms
Physical (PHY) Layer:
Responsible for putting bits "on the air".
For 802.11-based applications, the following functionality is not defined by 802.11 and must be implemented by the Application Layer (i.e., your code):
- Choosing a Radio Frequency (RF) channel to start/join a network
- Choosing which network to join
- When to start/join a network
- When to (re-)associate with a network