AUSTIN, Texas -- Movies and TV shows lead us to believe that when you dial 9-1-1, operators automatically know your exact location; but the Travis County Sheriff's Office says that's not the case.

We rely on our cell phones for just about everything, but in an emergency situation, they may not live up to our expectations.

"A lot of people think we know exactly where you are when you call us, but we don't,” said Melanie Rhodes, Travis County Sheriff’s Office Communication Supervisor. “We need for you to tell us so that we can send an officer to your location."

911 dispatchers for the Travis County Sheriff's Office say most people think that dialing 911 from a cell phone provides their GPS location.

"When a person is in a very distressed situation, the first thing they want is to get out what's going on, and that's important, we're gonna need that immediately, but the address is gonna be so critical," said 911 dispatcher Charlotte Trevino.

And in some cases, dispatchers are left helpless without that information.

"A coworker of mine was saying that she received a call from a woman who was calling from a phone, and she didn't know where she was and she was being attacked, and there's really nothing that we could do about it," said Rhodes.

While a cell phone can ping off of the nearest tower, that isn't enough - especially in rural parts of the county.

"The typical thing that comes in is from a cell tower,” Trevino said. “That can be a five mile radius of where they are, and I have no idea where a person is unless they tell me."

If you don't know the specific address, dispatchers say giving intersections or nearby landmarks can help.

"Maybe somebody stabbed you and you're bleeding, you don't know how fast that’s going to become fatal,” said Trevino. “We need to be able to get there fast."