[Tinyos-help] Tinyos Delay

Deeksha Rao Sahib ecedeek at ece.iisc.ernet.in
Tue Apr 6 10:18:55 PDT 2010


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
>> >>
>> >> --
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>> >>
>> >
>> >
>> > --Deeksha
>> >
>>
>>
>> --Deeksha
>>
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>
>
>
> --
> Best Regards,
> Arik Sapojnik
>
> --
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>


--Deeksha

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