Forum: GNU Radio Maximum length of packets using benchmark_tx/rx and packet_utils

3bcfc627a2c1d1dc13731223a2cd188b?d=identicon&s=25 Chris Valenta (Guest)
on 2013-02-28 02:03
(Received via mailing list)
Hey all,
I'm curious if there is a reason why the maximum length for a digital
packet payload is 4096 bits in packet_utils.py Currently this is limited
because of the length of the whitening mask, but if whitening is not
used...could this be increased? I know the framer_sink limits the length
of the total packet to 16 bits, but I'm using far less than this with no
success.

I've tried disabling whitening and commenting out the packet length
restriction of 4096 bits and put a larger packet through and it will
transmit fine, but not receive a correct packet. The received packet is
truncated as if all 16 bits in the framer_sink d_header_len limit aren't
being used.
Am I correct in this?
C539637020fd56193dd6daec746c4a84?d=identicon&s=25 Tom Rondeau (Guest)
on 2013-02-28 15:08
(Received via mailing list)
On Wed, Feb 27, 2013 at 8:03 PM, Chris Valenta
<valentac@sbcglobal.net>wrote:

> restriction of 4096 bits and put a larger packet through and it will
> transmit fine, but not receive a correct packet. The received packet is
> truncated as if all 16 bits in the framer_sink d_header_len limit aren't
> being used.
>
> Am I correct in this?
>

Chris,

I would assume that you can extend the packet length as you are trying.
But
it's possible that there is logic in the receiver that also expects
packets
to be 4096 or less because of this restriction in the transmitter. I
honestly can't remember off the top of my head.

But if you've removed the whitener, just remember that it's there for a
purpose to scramble the bits transmitted, so make sure you are
transmitting
random values to make the packets look white or you may run into issues
with the synchronizers.

Tom
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