[Tinyos-help] [Q] Measuring of round trip time between two motes

[Chong Hui Kim]

Dear all,

I have measured round trip time between two motes using Timer B.
I called one mote was TX mote and the other was RX mote.
To measure the round trip time, I read the Timer B register of "TX mote" before call SendMsg.send() the Timer B register of "TX mote" after ReceiveMsg.receive() event, and computed the difference of two time values.

In my experience, I set the control peiord as 50ms, 100ms, 500ms, and 1000ms.
For 50ms, 100ms, and 100ms, average round trip time was 22ms, max time was about 35ms, and min time was about 9.6ms.
For 1000ms, average round trip time was 14.5ms, max time was about 19ms, and min time was 9.6ms.

I found that average and max round trip time decreased for 1000ms period.

How can I explain this result?

Thanks in advance,
Chong Hui Kim.
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