Right I understand now..I don't need to keep my units with in the command radius if they have radio communications...is one or two soldiers dedicated signals men and when they are killed no more wire laying? Or does any soldier do it?
Yes. men from telephone/cable group. If not, there is no connection. Yes, they can be killed. To communicate need a cable, any soldier can't carry it.
But you may do a voice communications if arrange troops in compact group.