[Tinyos-help] LQI measurments with Tmote-Sky sensor?

[rahim_net at yahoo.fr]

Hi,

I'am using Tmote Sky sensors and I need some help about LQI measurments.
To calculate LQI values I use Delta application with the trawler tool. I' have some remarks.
with a maximum of power transmission (0dbm) and
distance of 3 meters, I found stronge values. However,
in the literature we speak about a value between 50 and 110 
then I'
have these questions:
1)-  why values upper than 110 and  lower then 50 even under
perfect conditions.
2)-  Why values are very large (few thousands)? However in
the standard 802.15.4 it is mentioned that the LQI value is an integer between 0 and 255 (on 8bits)
3)- Since the LQI is calculated when a packet is received, how about the packet when the value is higher than 110 or especially
255. (is it droped, is a bad packet, is it normal to calculate to calculate a very high value (thousands))?
4)- is there an other mean to calculate LQI values without using Trawler? is a manner to debug this directly in a console?
5)-  Are the values on the Trawler tool the true calculated values of LQI?.

thanks for your help in advance.
Denzel


      
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