I travel by air almost every week, and many of those trips are to locations outside of the USA. In many airports I used to find cell service a little spotty. That is until (Through many observations of fellow travelers, cabin crews and airport employees.) I learned the secret to having the best service possible in any airport.
Here’s the tip…make your call from the center of any concourse. You’ll find the best results if you drag your oversized carry-on and computer bag (a large purse may be substituted ladies) and place them on both your left and right side, while facing either direction along the path of traffic. You may also face a gate, but then adjust the bags so one is in front of you and the other behind. It’s optimal to do this in front a of gate that is preparing to board, but only if the boarding area is small enough to ensure the passengers are queuing in the concourse.
Now…I haven’t fully tested this technique but can say, after 100’s of observations, that it’s certain to work.