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1. Wireless network activity.
2. Ethernet port activity.
3. System LED with alternate mode for cellular modem status indication.
4. Signal strength.

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Cellular connection technology based on the System LED color:
Red: GSM
Yellow: 3G
Blue: LTE
Green: 5G NSA
Violet: 5G SA 

System LED alternate modem mode indications

When cellular modem interface is enabled, System LED have have alternate indications:

blinking - connection establishment in progress, modem registered in cellular network, APN is not activated yet

yellow  - established connection in 3G mode

blue - established connection in LTE mode

green - established connection in 5G NSA mode

violet - established connection in 5G SA mode

blinking red  - SIM card not inserted

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SIM slot usage

SIM card slot is designed to use with Micro SIM cards.
Nano SIM cards have different thicknesses, usage with an adapter is not recommended.

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