About Adaptive Frequency Hopping (AFH)

Hi Nordic,

I am using SDK 12.3.0 and S130 2.0.1. I have some questions about AFH.

1. Do Nordic stack keep track of some bad channels during communication and would skip the bad channels next time or there is no measurement of failure rate on a channel to black list it?

2. If there is no way to skip bad channels in BLE stack automatically, is there any solution we can skip the bad channels in application level? I know channel map is one of the solution but I want to know if I can count the failure rate on each channel during communication and setup a proper channel map over time.

3. What is the range of channel map? Can I just use 1 channel if needed?

Thanks.

  • Hi,

     

    Do Nordic stack keep track of some bad channels during communication and would skip the bad channels next time or there is no measurement of failure rate on a channel to black list it?

    No, the SoftDevice does not do this.

    If there is no way to skip bad channels in BLE stack automatically, is there any solution we can skip the bad channels in application level? I know channel map is one of the solution but I want to know if I can count the failure rate on each channel during communication and setup a proper channel map over time.

    A channel map update is driven by the master side. The problem here is that the Softdevice stack does not expose meta data, like re-transmits on a given RF channel etc, so this isn't easy to implement. Phones usually ban their currently used wlan channels to avoid overlap.

    3. What is the range of channel map? Can I just use 1 channel if needed?

    The minimum, per the bluetooth core spec v5 (vol 6, part B, chapter 4.5.8.1), is 2.

     

    Kind regards,

    Håkon

     

     

     

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