On Broadcast in Radio Networks- Priblem Analysis and Protocol Design Imrich Chlamtac & Shay Kutten ABSTRACT In this paper we develop a graph-oriented model for dealing with broadcast in radio networks. Using this model, optimality in finding an optimal protocol is NP-hard. A polynomial time algorithm is proposed under which a channel is assigned to nodes from global, multiple-source broadcasting considerations. In particular, nodes participating in the broadcast do not interfere with each other's transmissions, but otherwise simultaneous channel reuse isparmotted. Protocol implementations of this approach by frequency division and by time division are given. It is shown that, using these protocols, bounded delay for broadcasted messages can be guaranteed.