Distributed Coordination Function (DCF)

The 802.11 DCF is responsible for many behaviors. These actions include (but are not limited to):

• Acknowledging good receptions
• Retransmitting failed transmissions
• Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA)
• Binary Exponential Backoff (BEB)

The purpose of this document is not to explain or defend aspects of the DCF. Instead, this document is to aid in the understanding of how the standard DCF behavior is realized within the Mango 802.11 Reference Design. This document is intended to be read alongside the actual wlan_mac_dcf.c​ and wlan_mac_low.c​ code themselves.

Rather than structure this documentation as a function-by-function pseudocode equivalent to the above-linked codebases, we will instead approach the documentation from the perspective of two different roles: MPDU transmission and MPDU reception. There is overlap between these roles in what functions they execute (e.g., MPDU transmission still has an element of frame reception to deal with acknowledgments).

MPDU Transmission

Pseudocode:

	if

MPDU Reception