Cell phone towers produce a signal that is as close to a flat pattern as possible. As a practical matter, this signal doesn't reach very high and most aircraft are shortly out of range. However, the annoyance level to the pilots continues in headsets or on the cockpit speaker as a regular buzz as long as the offending cell phone searches for a signal. Absent a dramatic change in the patterns of signals produced by ground-based towers, conventional cell phone service is not coming to high-flying aircraft. The problem will control itself. Relax and enjoy.
Mark Bragg
