I'm sitting in the airport, waiting to pick someone up as I write this.

I just moved from a standing spot 50 feet away from where I am now sitting, finding a new power outlet to charge my iPhone while picking up a much better cellular signal in the process. I wasn't able to load web pages 50 feet away; everything in Safari is running smoothly now. I'm not sure I would've received any calls at my old standing spot; here at my new spot I know I will.

Sometimes it's just a slight, small change that can make all the difference in what you're doing. You just have to move a bit, and see if the reception improves. It could make the difference between getting a call and missing it.