Get Wi-Fi protocol (802.11a/b/g/n) programmatically

Question

Through WifiManager, my Android app can get a lot of details about Wi-Fi. However I fail to get protocol type like a/b/g/n. I have a client requirement to do that.

Answer 1

You can partially deduce the protocol from the link speed

WifiManager.getConnectionInfo().getLinkSpeed()

By Wikipedia 802.11 protocols speed table you can tell if it is 802.11b, 802.11n or 802.11ag.
802.11n and 802.11ac full link speed tables

Link speeds of protocols 802.11a and 802.11g are the same, you can distinguish between them by the used frequency (5GHz or 2.4GHz) in the scan results.

Note that protocol can change during the connection, client and access point do negotiate protocols and speeds but they agree on a list and not on one specific speed.

I don't think there is a way to distinguish between 802.11n and 802.11ac in their overlapping speeds.