No internet connection on my iPhone 6s Plus.

Hi, I need help. For the past week my internet phone service is very weak to the point where I have no service at all and I have to be restarting my phone every 5-10 minutes (about 10 times a day) in order to get service. Sometimes after restarting it, I still haven’t got any service. Btw my carrier is metro pcs. Can someone please help.