Close

3. LoRaWAN System Range Testing

A project log for Environmental Toolkit for an Ecological Area

LoRaWAN IoT system with the Arduino MKR WAN 1300, that help my community to monitor the air quality and water of our ecological area

Guillermo Perez GuillenGuillermo Perez Guillen 07/26/2022 at 19:110 Comments

The received signal strength indicator (RSSI) is a reference scale (in relation to 1 mW) to measure the power level of the signals received by a device in wireless networks (typically WIFI or mobile telephony).

The scale tends to the value 0 (zero) as the center; y represents 0 RSSI or 0 dBm. Although theoretically it can be the case of measuring positive values, generally the scale is expressed within negative values; the more negative, the greater the loss of signal. On this scale a level of 0 dBm is equal to 1 mW (milliwatt).

RSSI indicates received strength, not signal quality; since the latter is determined by contrasting the intensity of the signal with respect to the signal-to-noise ratio.

Below you can see a table that can serve as a reference for the signal intensity.

Signal strength (dBm)QualifierAppropriate uses
-30ExcellentThis is the maximum achievable signal strength and will be appropriate for any usage situation
-50ExcellentThis excellent signal level is suitable for all network uses
-65Very goodRecommended for smartphones and tablets
-67Very goodThis signal strength will be sufficient for voice over IP and video streaming
-70AcceptableThis level is the minimum signal strength required to ensure reliable package delivery and will allow you to browse the web and exchange emails
-80BadAllows basic connectivity, but packet delivery is unreliable
-90Very badA noise that inhibits most functions
-100WorstTotal noise


LINK TESTS WITH THREE TYPES OF ANTENNAS

The quality of the signal is bad according to our table, in the image below we see reception signals between -97 and -102 dBm.

The signal improved remarkably between -64 and -76 dBm, I only observe some instability in maintaining the signal as it goes up and down continuously.

The signal is good and stable, staying between -64 and -69 dBm for a long time.

Honestly, sending a message between two nodes in short links can feel like a real accomplishment. But the industry-wide excitement around LoRa is anchored in its long-range communication capabilities.

LONG LINK TEST 

Discussions