[Tinyos-help] Tinyos Delay

Arik Sapojnik sapojnik at gmail.com
Tue Apr 6 12:14:24 PDT 2010


I tried to raise the same questions on this forum several months ago, but
also didn't get a clear answer.
So, relying on this (the lack of negation) and on My results, the results
posted here:
http://sourceforge.net/apps/mediawiki/takatuka/index.php?title=Results
And here:
http://www.pats.ua.ac.be/content/publications/2009/dvdakker09tinyspotcomm.pdf

I conclude that this is the minimum achievable delay.

Arik



On Tue, Apr 6, 2010 at 20:18, Deeksha Rao Sahib
<ecedeek at ece.iisc.ernet.in>wrote:

> Hey Arik,
>
> So can i conclude that this min delay cannot be avoided??
> > Hi Deeksha,
> >
> > I have investigated the same issue, and tried to reduce the CSMA
> > thresholds;
> > but couldn't achieve less then about 18 mSec (average).
> > Of course it depends on the packet's size.
> >
> > Arik
> >
> >
> > On Tue, Apr 6, 2010 at 15:56, Deeksha Rao Sahib
> > <ecedeek at ece.iisc.ernet.in>wrote:
> >
> >>
> >> Hi,
> >>
> >> If the delays are due to backoffs then disabling the CCA should give me
> >> lesser delay rite??
> >>
> >> But its still the same..
> >>
> >> Printing local times at CC2420 Transmit and Receive programs what i
> >> found
> >> out is that at the sender there is a min delay of 9ms between call
> >> AMSend.send command and the SendDone event.
> >>
> >> Also at the receiver side there is a delay of 13ms by the time receive
> >> event is triggered in the application when compared with the timestamp..
> >>
> >> Can these delays be trusted or is there any mistake in this analysis??
> >>
> >> >
> >> >> On Wed, Mar 31, 2010 at 1:40 AM, Deeksha  Rao Sahib
> >> >> <ecedeek at ece.iisc.ernet.in> wrote:
> >> >>>
> >> >>> Hi all,
> >> >>>
> >> >>> I am using FTSP in my code for time sync and I've been trying to
> >> >>> measure
> >> >>> the hop delay for different links in the network. From the initial
> >> >>> tests
> >> >>> using global time and the timestamps i figure out that the per hop
> >> >>> delay
> >> >>> is about 20 ms.
> >> >>>
> >> >>> My applications requires that this delay be minimized. How can this
> >> be
> >> >>> done??
> >> >>> Any inputs would help...
> >> >>
> >> >> Some of that delay is due to MAC backoffs etc. before the packets are
> >> >> sent. You can reduce them but that can invite suboptimal MAC
> >> >> performance.
> >> >>
> >> >> - om_p
> >> >>
> >> >> --
> >> >> This message has been scanned for viruses and
> >> >> dangerous content by MailScanner, and is
> >> >> believed to be clean.
> >> >>
> >> >
> >> >
> >> > --Deeksha
> >> >
> >>
> >>
> >> --Deeksha
> >>
> >> --
> >> This message has been scanned for viruses and
> >> dangerous content by MailScanner, and is
> >> believed to be clean.
> >>
> >> _______________________________________________
> >> Tinyos-help mailing list
> >> Tinyos-help at millennium.berkeley.edu
> >>
> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
> >>
> >
> >
> >
> > --
> > Best Regards,
> > Arik Sapojnik
> >
> > --
> > This message has been scanned for viruses and
> > dangerous content by MailScanner, and is
> > believed to be clean.
> >
> >
>
>
> --Deeksha
>
> --
> This message has been scanned for viruses and
> dangerous content by MailScanner, and is
> believed to be clean.
>
>


-- 
Best Regards,
Arik Sapojnik
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