Hi Faisal,
U can put some seqeunce number in the packet at the application layer,
but then, if MAC has to retransmit the packet because it gets lost in
collision, it will maintain the same application-layer sequence number, it
will not update ur sequence number, so at the receiver u'll receive the
packet with the same seq number as u put in the sender, so u won't even know
that there was a collision which resulted in a retransmission. So u'd never
know how much time was wasted for collisions and retransmissions. Anyway, if
u think that this time is negligible from ur application's point of view, u
can go for it.
Bibudh
Bibudh Lahiri
Graduate Research Assistant
Department of Electrical and Computer Engineering
Iowa State University
http://www.ece.iastate.edu/~bibudh/
On 4/2/07, Faisal Karim <[EMAIL PROTECTED]> wrote:
Hi Bibudh
1) Thats true, I also dont know the answers yet :-) after these
experiments I'll try them on real motes as well.
2) For second problem you are right and that was the reason I asked the
question on list. And one interesting observation is the difference between
receive() and sendDone() is always 31 seconds within single hop.
I was thinking to start considering the timing from send() instead of
sendDone() by this the processing time, queuing time etc will also be
considered. One concern can be than may be the send() will not send
packet(collisions etc), so to hack around im thinking to put some sort of
sequence no. or identifier in packet at src than check that on receiver.
Any suggestion
Regards
Faisal
----- Original Message ----
Date: Mon, 2 Apr 2007 14:04:34 -0500
From: "Bibudh Lahiri" <[EMAIL PROTECTED]>
Subject: Re: [Tinyos-help] sendDone() called before receive
To: tinyos-help@millennium.berkeley.edu
Message-ID:
<[EMAIL PROTECTED]>
Content-Type: text/plain; charset="iso-8859-1"
Hi Faisal,
As an idea, it sounds OK, but I'd like to mention a thing or two:
1) I'm not sure how close this would be to the transmission delay that u'd
obtain on real motes
2) If the problem of receive() being called in the receiver before
sendDone() being called in the sender persists (as u reported), then u'll
have a problem.
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