I would trust ED (which has higher resolution anyways) over RSSI, but I have no proof that it is better. Miklos
2011/10/5 Marc Barceló <[email protected]>: > Hi Miklos, > > Yes, I have done it and many other tests to discard other reasons. The > conclusion is that in the same conditions the two measures give different > values in dBm. In this case, which measure do you thing should we trust? Do > you agree that the ED measure should be equal or lower than the RSSI measure > since it only considers IEEE 802.15.4 power? > > Thanks in advance, > > BR > > Marc > > El 05/10/2011, a las 12:03, Miklos Maroti escribió: > >> Hi Marc, >> >> 10 dBm difference between two motes is completely normal. You should >> reverse the roles of the two nodes and compare the result. >> >> Best, >> Miklos >> >> 2011/10/5 Marc Barceló <[email protected]>: >>> Hi Miklos, >>> >>> Thanks for the answer. I have not changed the RF230DriverLayerP file. In >>> fact, I have used both measurements in two different motes but using >>> exactly the same conditions. I think it is normal to have some dB between >>> them, but I think the difference is too high. Any idea about the reason >>> then? >>> >>> On the other hand, since the ED measure only measures the IEEE 802.15.4 >>> packets power, should it not give always equal or less power than the RSSI >>> measure, which takes into account every signal received in the measured >>> region? >>> >>> Thanks in advance for the help, >>> >>> Marc >>> >>> >>> El 05/10/2011, a las 10:03, Miklos Maroti escribió: >>> >>>> Hi Marc, >>>> >>>> Have you changed the RF230DriverLayerP file? I think the ED and RSSI >>>> measurements are not performed at the same time. The ED is done >>>> automatically by the hardware after the SYNC byte is received, while >>>> the RSSI is done manually when the first interrupt is handled. This >>>> could cause some difference. >>>> >>>> Best, >>>> Miklos >>>> >>>> 2011/10/5 Marc Barceló <[email protected]>: >>>>> Hello to everyone, >>>>> >>>>> I am a researcher working on WSN, using IRIS motes (which use RF230 Radio >>>>> Hardware). I am measuring the received power from one mote to another. >>>>> The RF230 datasheet says that two different measures can be used, Energie >>>>> Detection (ED) or Received Signal Strength Indicator (RSSI). To convert >>>>> the measured values to dBm, according to the datasheet, for the first >>>>> case it is necessary to do: PRF = ED_VAL -91. For the second case the >>>>> following has to be done PRF = RSSI_BASE_VAL + 3•(RSSI - 1). The problem >>>>> is that these measures does not seem to be equivalent since using the ED >>>>> measure I receive more power( a difference greater than 10 dB) in >>>>> comparisson with the RSSI measure. I am using the Basic operating mode >>>>> so, since what I know, both measures should be very similar. >>>>> >>>>> I would appreciate any help, >>>>> >>>>> Best Regards >>>>> _______________________________________________ >>>>> Tinyos-help mailing list >>>>> [email protected] >>>>> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help >>>>> >>> >>> > > _______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
