[Tinyos-help] Tinyos Delay

Arik Sapojnik sapojnik at gmail.com
Tue Apr 6 22:59:00 PDT 2010


Deeksha,

Look here why we couldn't configure the thresholds...

Arik


https://www.millennium.berkeley.edu/pipermail/tinyos-devel/2010-April/004371.html

On Tue, Apr 6, 2010 at 22:14, Arik Sapojnik <sapojnik at gmail.com> wrote:

> 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.
>>
>>
>
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