Hi!
On Wed, 12 Aug 2009, Rémi Villé wrote:
2009/8/12 Omprakash Gnawali <[email protected]>
On Tue, Aug 11, 2009 at 9:31 AM, Rémi Villé<[email protected]> wrote:
2009/8/11 Rémi Villé <[email protected]>
2009/8/10 Omprakash Gnawali <[email protected]>
On Mon, Aug 10, 2009 at 7:14 AM, Rémi Villé<[email protected]>> wrote:
2009/8/6 Rémi Villé <[email protected]>
2009/8/6 Rémi Villé <[email protected]>
Hi,
I would like to count the number of transmissions/retransmissions during
a simulation with TOSSIM.
For now, I only need to write this count on stdout using gdb(), but I
dont know where is the ideal place to add it, I would like to estimate the
number of (re)transmissions with as much accuracy as possible.
Thanks,
Rémi
It's dbg().
I must do that because I have modified the CtpRoutingEngine to use node to
node similarity, and if I count the number of transmission using only
Send.sendDone (of CollectionC.CollectionSenderC), I have not the total
number of retransmission/retransmission...
You can put your debug statements in the AM layer.
- om_p
I didn't find exactly where to put the dbg statement in the AM layer yet,
but maybe it would be a better idea to measure the data throughput (packets
per second delivered) in the java application, it may be equivalent and
costless for nodes in a future real deployment test.
I think the good place to put the dbg statement is in "event void
Model.sendDone(message_t* msg, error_t result){...}" in the
tos/lib/tossim/TossimActiveMessageC.nc file, but I'm not sure it includes
Ack and re-transmissions...
CTP retransmissions are done using the AM layer: each retransmission
is a new packet as far as the AM layer is concerned. As long as you
instrument the AM layer, you should catch all the retransmissions.
- om_p
Thanks for your help, I think I can distinguish ack and other transmission
thanks to
tossim_metadata_t* metadata = getMetadata(msg);
and
metadata->ack != 0
You can take a look in the TossimPacketModelC.nc to see how the ack
field is used. It's set to TRUE when the .requestAck is called and then is
returned as the answer for the .wasAcked. The model is suppose to set it
to FALSE if the packet did not get to the destination.
So, to make thinks clearer: there is ack packet in TOSSIM. The
PacketAcknowlegements interface is simulated just by tracking in a
variable (the ack from metadata) if the packet got it to the other end or
not.
It's not a crucial question for me now, but is there a parameter in
tossim_metadata_t, tossim_header_t or tossim_footer_t which can allow me to
distinguish transmissions and re-transmissions?
The re-transmissions in CTP are application layer re-transmissions. Said
differently, CTP doesn't use the PacketLink interface that can
automatically retransmit the packet up a certain number of times. So I
think you should probably instrument the CtpRoutingEngineP.nc to print at
each send something informations about the packet that will allow you to
know when the same packet is sent. There might be already some dbg
statements that do this already there. :-)
Note: I presume you are not using the CC2420sim.
All the best!
Razvan ME
_______________________________________________
Tinyos-help mailing list
[email protected]
https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
