[Tinyos-help] mica2 vs. telosb range

[David Moss]

Interesting results.  Hardware wise, there are a few 
possibilities that I can think of:

* Antenna type - the telosb inverted-f antenna is a very 
good antenna.  The whip antenna attached to the mica's are 
much worse.  The impedance matching on older mica2's is 
very poor, which will significantly decrease the range.

* Interference - there's plenty of interference in the 900 
MHz band, especially with FSK on those CC1000's.  The 2.4 
GHz CC2420 uses DSSS, which is less likely to be affected 
by interference.  The 900 MHz cell phone bands surround 
the 900 MHz band, and spurs coming from the cell phone 
bands have been known to affect the link performance. 
 Also, any other 900 MHz device will negatively affect 
performance.  The solution is to add SAW filters to the 
antenna network, but that's pretty much a no go with 
off-the-shelf hardware.

If you're consistently finding that the 2.4 GHz spectrum 
performs much better in your environment, then go for it. 
 The tmote is a very solid, robust platform to develop on.

-David



On Sat, 03 Feb 2007 23:00:20 -0500
  Bruce <bedesign at optonline.net> wrote:
> Hi
> 
> Can anyone tell if they have had similar results. 
>Indoors using the inverted
> 
>F pcb antenna on telosb (2.4 GHz) we get approximately 
>300 feet between
> 
> motes and using the 900 MHz motes with the default 
>configuration we get
> 
> about 150 feet range. 
> 
> 
> 
> Thanks,
> 
> Bruce
> 
> 
>