Frequency sharing is when two or more transmitters use the same transmission frequency.
Frequency sharing can refer to the fact that the transmitters are geographically correspondingly far apart and do not interfere with each other, but it can also be a time-delayed use of the same transmission frequency. Frequency division multiplexing. A frequency range can also be split by dividing the frequency range into individual transmission channels and assigning the different channel frequencies to different transmitters.
The frequency division technique is used when there may be interference between different transmission frequencies or when the use of multiple frequencies is not possible.