Intentional radiator

An intentional radiator is a thing that sends out signals like a radio or Wi-Fi router. They have to follow certain rules to make sure they don't disrupt other signals in the air. It's like when you're playing with your toy car in the living room, you have to be careful not to bump into the furniture or people around you. Intentional radiators are the same way, they have to follow the rules or they might interfere with other signals and cause problems.