You must activate this service mode. This goes on the Samsung Galaxy S6 as follows:
1. Opens the home screen of the phone app
2. Changes here on the "keypad"
3. Give the following code on the numeric keypad: * # 0011 #
4. There now opens the service mode on the Samsung Galaxy S6
5. Typing top right on "More" and then on "WiFi"
6. Now Playing select "WiFi Power Safe Mode"
7. If this mode of "A" to "Off"
Your Samsung Galaxy S6 will now always use the highest transmitting and receiving performance of the Wireless Modules. This should now be ensured that your smartphone connects perfectly with the wireless network of your router.