i am just wondering how radio communication for a company works. I brought so many books but nobody seems to have straight forward answer or may be i have to dig a bit more. But before that lets ask to yahoo community to get some clue. how to select a specific rf signal and a propagation mode for the design and which modulation technique i will use and why? What about the radio transmitters? How can i draw a diagram of my design? Any few good links would do from the respected experienced radio engineers.