I found the appended THread in the archive.
That time, there was no answer to this mail.
But I have exactly the same problem to understand the architecture of
the packets.

It would be nice, if anyone could write a short explanation why the \x55
and the preamble are added to the packet.

Thanks a lot.


Hi all,
I was going through the and just to try and
understand how packets are generated. Is it right to say that preamble
has not being added to the payload?
“(packed_preamble, ignore) =

If it is being added how is it helpful on the receiver side because i
don’t see where it has been used or extracted. I know that it can be
used to contain the training sequence for channel estimation but i doubt
it has been used for the same here. I can only see the access code
correlator to mark the beginning of payload and no correlator for the
preamble. Is it right to assume that the access code correlator alone
can be suffice? What is the significance of ‘\x55’ at the end of
the packet before introducing usrp pad? I am asking because according to
my understanding it should make the end of payload(post amble) but I
don’t see a correlator for it.

Kind regards,