Just FYI, in the U.S.:
Cell sites typically emit about about 10 watts ERP (or less) per channel.
Cell phone transmitters can use many different frequency bands, depending on where you are located:
698-793 MHz (former TV Station analog broadcast frequencies)
824-849 and 869-894 MHz
1710-1755 MHz
1850-1995 MHz
2110-2155 MHz
The following frequencies may also be used, but to a much lesser extent:
2300-2360 MHz
2500-2700 MHz (MMDS or BRS - used for point-to-point networking/cable TV)
5150-5925 MHz (U-NII power limited to 250mW in part of the band, 1W in another)
Most consumer drones operate on the following frequencies:
2400-2483.5 MHz (also known as "Wi-Fi")
5725-5850 MHz (also known as "Wi-Fi")
DJI transmitters emit about 355mW (0.355W) in the U.S.
As
MaverickMavicMark said, there may be overload of the front end of the receiver in your drone if you fly too close to a transmitting antenna, even if it isn't on the exact frequency you are using. Best to approach slowly and if anything strange happens, pull the stick back and back out the way you came in.