Hi. I have poor mobile signal in my home, on my old Galaxy S4, I had intermittent signal to get calls and texts, now on my upgraded Galaxy S6 its worse, hardly anything is coming through. When I have received texts it has been the day after they were sent.
Welcome to the community and thanks for posting. I'm sorry to hear you're having signal trouble with your new Galaxy S6.
You can check the signal coverage in your area here. I also have to point you in the direction of the disclaimer at the bottom which reads:-
"This map is only a guide and is not a guarantee of service availability in a particular location. It shows outdoor coverage only. As with all radio-based systems, service may be affected by a number of local factors, such as building materials, tree cover and weather conditions".
Do you get a decent signal away from home?
Do other networks have trouble at your property?
In summary, no one can guarantee an indoor signal because of the things mentioned. The S6 could possibly have an antenna problem but if the signal is fine elsewhere then it could dispel this theory.