I get very poor cellphone reception in my house. My S5 is running Android 5.0. My network is Straight Talk (Verizon) from Walmart. It is my understanding that I can't connect to my home wi-fi for cellphone calling. Is this true? Is there any way I can connect to my wi-fi? I really don't want to buy a Verizon signal booster for $250.00!! Any help would be appreciated. Thanks.