Communicating on a battle field is crucial.  As the battlefield becomes more complex, more information needs to be shared and more people need to know about it.  Secure, undetectable communication is a holy grail of battle field communication.  If the enemy knows what you are telling others, then they can take appropriate action.  The next best solution is to at least know someone is in the area and talking.  That alone can help the enemy figure out what the other side knows and is talking about, or preparing to do.  The shorter the transmission, the harder it is to locate the transmitter.  Like homing in on a sound in a dark room.