Hi Peng, If RSSI is low, it will be a very good estimator of no-signal received. But if RSSI is high, you need the LQI to be sure that the signal is still useful. The LQI means exactly that: Link Quality Indicator. I guess it is defined in the 802.15.4 standard, and the CC2420 just implement it in order to be compliant.
Cheers! Sergio On Wed, Jun 15, 2011 at 5:07 PM, Peng Du <[email protected]> wrote: > Thanks Sergio, > > So does it mean RSSI can only be used to detect potential problem such > as an obstructing object which cause the value to decrease, rather > than interference caused by nearby communications? > > And what is the other indicator in CC2420? Is it LQI? Or it has to be > manually calculated? > > Cheers, > > Peng > > On 15 June 2011 16:00, Sergio Valcarcel <[email protected]> wrote: > > Hello Peng, > > it is quite simple. RSSI is measuring power, it does not matter quite > much > > whether it comes from noise, interference or useful signal. > > That is the reason because there is another quality indicator which > measures > > signal to noise ratio. > > Cheers! > > Sergio > > > > On Wed, Jun 15, 2011 at 4:14 PM, Peng Du <[email protected]> wrote: > >> > >> Hello everyone, > >> > >> I always thought the RSSI value read from received packets would fall > >> as the interference grows. However I just found that the reading > >> actually rises when I switch on a commercial interference generator.. > >> > >> Would anyone point out why this is happening? Thanks very much. > >> > >> Regards, > >> > >> Peng > >> _______________________________________________ > >> Tinyos-help mailing list > >> [email protected] > >> > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help > > > > >
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