Coexistence is a big topic and I may have to refer you to public literature. But suffice to say that the chipsets in this forum support the standard AFH as defined in BT SIG.
A high level overview of AFH is as follow:
1) To determine whether the channel is good or bad (occupied with other 2.4GHz devices) using RSSI or PER assessment.
2) To determine the "clean" channel map
It is adaptive to the spectrum in the sense that BT will avoid those crowded channels and use only the "clean" ones.
Thank you BoonT_56!
I'm asking this as on paper other modules (like TI) also support AFH. In BLE mode however, users report that some of these chips are just doing static-hopping and make obviously no use of a channel map. So I wanted to double check the behaviour of the Broadcom chips in BLE mode.
The hopping and channel map is integrated in BCM20737's transceiver itself, so the F/W and code running on it has no influence on this? In other words: I can run whatever firmware I want, the adaptivity and channel map is always enabled in BLE Mode?
I just learned that sometimes proper AFH in the sense as you described it only happens in standard BT mode and is often not implemented in the BLE stack of single-mode modules (hardware restrictions/cost reasons).
Does the AFH as you described it also happen in the LE stack (single-mode modules) and not only the standard mode (dual-mode modules) of Broadcom Modules?
I refer to page 9 of the 20737 datasheet and it states that the chip supports AFH in a manner described like the above, including the derivation of a channel map. For a user like us, AFH will just work and we do not need to "turn on" this feature in the FW.