Wireless transmission is unguided medium of sending data. Wireless communication involves no physical media to be involved during transmission, communicating wirelessly. Wireless signals are spread over the air and received by the antennas.

When an antenna is receives the signal ,it converts the digital data into wireless signals and spread all over within its frequency range. The receptor on the other end receives these signals and converts them back to digital data.

Radio Transmission

Radio waves of lower frequencies can be communicated through the shorter distance whereas the radio waves for high frequencies are used for longer distance communication.Its power decreases as the distance gets increases. High frequency radio waves have more power.

Radio waves of high frequencies are   absorbed by rain and other obstacles. They use Ionosphere of earth atmosphere. High frequency radio waves such as HF and VHF bands are spread upwards. When they reach Ionosphere, they are refracted back to the earth.