What is the point of Wi-Fi Association?

Question

In the 802.11-2020 standard, you can read, regarding 802.11 Association

To deliver an MSDU within an ESS via the DS, the DS needs to know which AP within the ESS to deliver the MSDU, so that the MSDU might ultimately be delivered to the addressed IEEE 802.11 STA. This information is provided to the DS by the concept of association.

Since Association happens after Authentication, and that Authentication is "directed" in that a STA sending some Authentication Request has to specify the MAC Address of the STA it wishes to authenticate with, I don't understand this sentence, as the AP within the ESS should be known from the Authentication phase.

My question is therefore the following: what exactly is the point of Association in 802.11 networks, and what goal does it achieves that couldn't be achieved using the Authentication phase.

Answer 1

You might want to see association as 'plugging the cable'. Associating connects a WLAN node to an SSID. Authentication is (usually) a prerequisite for association.

At least in theory, the authenticator isn't necessarily the wireless bridge/access point that provides association.

Answer 2

The Association means that the client is using the AP, in other words, there's a trust and a keep-alive - the authentication phase is the phase in which the AP or Controller acts as the authenticator for the client authentication.

You could implement different types of authentication - layer 2 or layer 3.

You can check the authentication and association status on almost all vendors in the industry today.

Best