[Tinyos-help] shorter (cc2420/telosb) radio range in t2 compared to t1?

[Philip Levis]

On Nov 4, 2007, at 5:41 PM, Jeongyeup Paek wrote:

>
> To close the thread for now... my hypothesis was wrong.
>
> I went back to
> t1/CntToRfm/TOSBase, t2/BlinkToRadio/BaseStation,
> on the same testbed and the range seems to be identical.
>
> The main difference between my code and above (I think)
> is capturing timestamp at sfd interrupt.
> I need further investigation and experiments with my code.
>
> Thanks to everyone for help.

Good to know. Thanks for following up on this. Yeah, interrupt  
handler durations are tricky on radio stacks; when Sam Madden was  
writing TinyDB, he observed something very similar, and it took him  
and Wei Hong about 2 days to figure out the cause was changing  
timestamps from 16 to 32 bits; the few extra cycles made packet  
reception drop by something like 80%.

Phil