If you notice in your Samsung Galaxy Note 4 that you can not receive phone calls or SMS, this may be due to an error in the Android system. Most of this appears only once, which is why you the following tip will help. This trick is used when the Samsung Galaxy Note 4 is no power, even though the bars are filled in the network signal strength indicator.
So in order again with the Samsung Galaxy Note 4 to connect to the wireless network of your provider, you must proceed as follows:
Does the status bar of your Samsung Galaxy Note 4 with two Fingerin down, then taps on the icon with the "aircraft". This is the airplane mode. Is the airplane mode enabled on the Samsung Galaxy Note 4, all compounds are separated with mobile Netzwen. This is important because then your Samsung Galaxy Note 4 tries to re-connect with existing networks again. This includes of course the mobile phone network.
After you leave about 20 seconds your smartphone in airplane mode, you can disable these again. Pulls to the status bar again with two fingers down and tapped again the "airplane" icon. That's it. Your Samsung Galaxy Note 4 should be connected to the wireless network and you be reachable again by telephone and SMS again.