What is "Channel Map"?

[Mitch996]

This concept keeps popping up when I'm dealing with mesh networking.

My guess is that, to avoid air collision, packets/pdus are sent on a randomized or predefined combination of channel frequencies, since BT allows a total of 40+ frequencies on the 2.4Ghz band, messages will be sent using this pattern:

23, 42, 48, 21 to avoid or minimize collision.

Can someone give me a concise yet condensed and accurate description on this?

[endnode]

Channel map is just restriction of "full" 37-channel space normally used during BLE connection for frequency hopping. If any side decides that some channel is noisy or it has other problems it can try to narrow the space but still the hopping sequence will be pretty much the same (just once it's turn on "excluded" channel then it jumps to next and so on). Now I don' know how exactly it works in BT SIG mash or other mesh technologies which are not using BT LE LL PDUs but I guess it's the same principle.

[run_ar]

Some more details about the channel map here. Note that when dealing with Mesh, you might not be connected? if so you are using the advertisement channels which is not part of the channel map.