GSM signal reception
Overview
Apart from signal strength important factor is stability of signal. Eg.:
- Device can work with -100 dBm, or even -104 dBm if signal is stable
- Device can have issues with -85 dBm if signal is going up and down
Values
| Best possible | Very good | Good | Low | Action recommended | Action required |
|---|---|---|---|---|---|
| -50 dBm | from -50 dBm to -70 dBm |
from -70 dBm to -89 dBm |
from -89 dBm to -94 dBm |
lower than -94 dBm |
lower than -98 dBm |
Troubleshooting
- Check if antenna is properly connected
- Use external antenna on cable if device is installed in metal box (install antenna oustide of the box)
- Use high gain external antenna in remote locations
- Move antenna (even changing orientation of antenna [rotate it] may affect signal)
- Send reboot SMS command (device uses a little more power for first connection and usually can setup initial communication). This "trick" should be used only to get information about signal strength or to force device to communicate for some time not as a permanent solution (!)