If you're experiencing signal problems frequently, then you should probably contact your network provider. On the other hand, you can also try fixing your problems by buying a home cellular booster. I haven't tried it myself, but from what I read from the website, it sounds like it could do a lot to increase your signal strength. It's a bit expensive, but if can really deliver results as promised, then I'd say that it's a pretty great find!
In case you decide to buy one, don't forget to tell me how it goes! I might need one for myself too. :)