Re: [Discuss-gnuradio] Carrier Sensing only in gr_packet_sink?

[Tom Rondeau]

On Fri, May 25, 2012 at 4:32 AM, Marius <address@hidden> wrote:
> Hi!
>
> I have a short question: in my implementation of a state machine to
> implement a parser for a MAC sublayer standard (802.15.4) I used a
> Sync-Block. Now I found out that carrier_sense() is only in
> gr_packet_sink class. Does this make sense at all? Normally I'd apply
> some Carrier Sensing right before modulation, mostly to avoid blocks
> wasting performance on iterating over noise. I'm aware that a Squelch
> Filter might archive a similar effect, but that still means the other
> Signal Block go into general_work() routines.
> So, why is carrier_sense() not in gr_sync_block etc.?
>
> Best,
> Marius

That packet sink block is very old and mostly just an example, now.
It's largely been replaced by frame_sink_1 and
digital_correlate_access_code_bb (note that we will be moving
frame_sink_1 into gr-digital in 3.7; there was some talk about
removing packet_sink altogether).

If you follow the benchmark examples in
gr-digital/examples/narrowband, we actually implement the carrier
sensing in there, prior to the modulation as you say.

Hope this helps.

Tom