Re: [Ubertooth-general] it is possible to configure ubertooth to a specific range of BT channels?

[Dominic S. <dom...@gm...>]

On 3 June 2014 12:39, Michael Mehari <meh...@gm...> wrote:
>
> First, you did increment 32 channels every time you hop in sweeping mode
and i wonder why you used 32 and how can i adapt it to variable bluetooth
channel ranges.

The jump was to avoid spending too much time in one part of the spectrum,
i.e. to avoid noise from other devices, or parts of the spectrum that the
target connections may not be using.  This way we spread those quiet spots
across the results, rather than having them all consecutive.  We also want
to avoid moving at the same rate as Bluetooth devices, we intentionally
want to collide with their channel choices at irregular intervals.

> Second, it is again on the sweeping mode and you switch channels 25 times
per second. Was there a good reason for this choice?

Sweep mode is used for surveying the spectrum, we aren't trying to receive
all of the Bluetooth packets, but rather to receive packets from all of the
piconets in range.  Hopping more slowly gives us the chance to see multiple
piconets as the hop past our current channel.

Changing either of these values should be as simple as changing the value
in the code, although you'll probably want to adjust the check in lines
1290-1291 to respect the range that you're setting on your Ubertooth.

Thanks,
  Dominic

> On Thu, May 22, 2014 at 7:32 PM, Dominic Spill <dom...@gm...>
wrote:
>>
>> On 22 May 2014 15:40, Michael Mehari <meh...@gm...> wrote:
>> >
>> > My problem was to assign specific ubertooth devices to a specific
spectrum band. For example, Ubertooth dev 1 to BT_channel 1-15, . . .
>> > I looked inside the sniffer source code (ubertooth-rx) and it seems it
only has two options. Either set to a specific channel or the entire 79
bluetooth channels?
>> >
>> > So my question is, it is possible to configure the ubertooth device to
a specific range of BT channels?
>>
>>
>> It's not possible with the current firmware, but would be possible with
some firmware modifications.  You could add a control message that set the
limited set of channels (or use the set_afh_map command) and then set the
desired hopping method.
>>
>> I assume you're not trying to follow a connection, but are more
interested in monitoring a section of the spectrum?  So you want to break
the spectrum up in to six parts and use an Ubertooth in sweep mode in each?
>>
>> Have you also considered using a software defined radio implementation?
 You would still need multiple radio devices (such as HackRF), but it may
be an interesting alternate angle to the problem.
>>
>> Thanks,
>>   Dominic
>
>
>
>
> --
> regards,
> Michael T. Mehari
> GSM: +32485310659