PC World
SAN FRANCISCO — In the race to get drones into the sky and zipping across cities delivering packages and snapping photos, cellular networks are quickly emerging as the preferred way of keeping them in touch with the ground.
But researchers are finding that getting a reliable signal a hundred meters up in the air isn’t as easy as it might seem, and that could present a challenge for companies like Amazon, which want to fly drones over distances greater than WiFi or similar technology allows and maintain contact with the craft during their flight.
The problem is that cellular networks are designed to provide coverage at ground level—where the customers are—and not up in the air. Take a look at any cellular base station antenna and you’ll notice its antennas points down, not horizontally or up.
Read full story: Drones get bad cell service, but an old ambulance will help