With the current digital phones there is almost no chance of the phones interfering with the airplane's operations. When phones were analog their frequencies d

With the current digital phones there is almost no chance of the phones interfering with the airplane's operations. When phones were analog their frequencies did live in some of same ranges as the plane's equipment. Analog phone used lower frequencies to cover longer ranges. Back then we had of fewer towers so you had to use lower frequencies. The lower the frequency the more ground you can cover, the better reliability. Airplanes used the similar frequencies for all the same reasons. Now both planes and phones use better equipment with better FCC oversight on was frequencies and transmission type each uses. Airplanes rely more on satellite communication then terrestrial towers which further helps to prevent radio communication collision.