Cell Phone Signals

I will never forget ten years ago when I was still using external antenna. I’d sometimes stayed in our roof and neighbor second floor balcony just to send SMS messages. Since we didn’t have cell phone sites yet near our place during that time. But how come there are still places even here in the metro where you will still need to use wilson cellular booster just to have cell phone signals? Hopefully time will come when there’s no need for us to climb up in the roof just to send an SMS message.