The default behaviour on Windows 10 is to "let Windows manage cellular connections’. This means that the cellular interface is used when Ethernet or Wi-Fi disappear.
My question is what state is the modem in when Windows is not using it (regarding EM transmission)? Is the transmitter turned off and the receiver just polled for signal strength, or does the transmitter get used at all when Windows is not using the Cellular interface?
The reason for asking is regarding EM issues in a medical device.
Per my own experience, I think “Let Windows manage this connection” means Windows can activate data session when WiFi/LAN is not available, thus it changes to “Connected” for data transfer thru 3G/LTE network.
However, when it is not connect, the modem still registered to the network, that means it can receive/transmit info with network (i.e. call/sms).
So the transmitter is not completely off, and it still can emit RF.
If you need it to be completely off, you may need to use the “airplane mode” option.
Also be careful over the settings, the other day I was doing some testing on a mangOH red and a WP76, the PC had a wired Ethernet connection. I subsequently had a teams meeting running video, screen sharing, etc, got to the end of the hour to back to my testing and found that the WP76 was rather hot as I had run the call over it so the routing might not default to what you think.
Normally though @lotam is correct the unit will power up, attach and then when idle (so no user data session running) perform tracking/routing area updates as required by the network periodically (default value is every 90 minutes but is normally set by the network), that’s also assuming the unit is stationary, if its moving then it will perform an update each time it moves into a new tracking/routing area.
My testing suggests that ‘Airplane Mode’ does not power-down the module. It appears to have the same effect as disabling the network interface in Windows.
Can you confirm that ‘Airplane Mode’ and ‘Disabling’ the network interface both result in no transmissions?
We want to use your module in a medical device and yet your datasheet suggests that the module must be de-powered when near medical devices. Could you clarify?
