RSSI

[tharun]

Hi all,

          What is a good RSSI for TRIO ER450. Can i have the RSSI classification of the industrial radios.

Thanks,

[Joel_Weder · Accepted solution]

I have attached a data sheet (brochure) for the ER450 radio. As it is obsolete, that datasheet is not available any more on our website. The basic radio sensitivity is -118 dBm for 12 dB SINAD. (see page 5)  But that number is more to compare against voice type radios. The data sensitivity will vary depending on the modulation type used in your radios. That is on page 6, but also here:

4800 bps    -111 dBm   NOTE: all measured at 1x10-6 BER (bit error rate)

9600 bps   -110 dBm

19200 bps  -106 dBm

For a reasonably reliable link quality, the industry standard is to design for at least 20 dB of fade margin. This is the difference between the radio's sensitivity (at configured data rate) and the predicted or measured signal level. So desired signal level is:

4800 bps   -91 dBm or more (less negative)

9600 bps   -90 dBm or more

19200 bps -86 dBm or more

I am not sure what you meant by "RSSI classification" If we have not answered this, please reply with clarification of that.

[tharun]

Please list down the RSSI stages (very strong. strong, weak) for trio ER450  as per the attached the image.

[Joel_Weder]

It's not quite so easy, because I don't know the configured radio data rate, which would tell me the radio's receiver sensitivity at that rate. So I won't give you exact dBm levels at this point. But for each general state, I can say what the approximate Fade Margin will be. You must go back to earlier comments or the ER450 data sheet we have shared, and find the specified data rate, which will tell you the sensitivity for the speed your radios will operate at.

Fade Margins: (approximate)

Below 0 dB  No communication

0-9 dB     Very weak

10-19 dB  Weak

20-29 dB  Good

30-39 dB  Very strong

40+ dB     Extremely strong

NOTE:  A 0 dB fade margin would occur at the point where the radio is hearing a signal equal to the specified receiver sensitivity in dBm at the over-the-air data rate of the radios.