k-port line broadcasting in trees

Broadcasting is the process of message transmission in a communication network. The communication network is modeled by a graph G = (V, E), where the set of vertices V represents the network members and the set of edges E represents the communication links between two given vertices. We assume that G is connected and undirected. One vertex, called the originator of the graph holds a message that has to be transmitted to all vertices of the network by placing a series of calls over the network. A k- port line broadcasting in G is a model in which an informed vertex can call, at each time unit, at most k vertices and transmit a message through a path, as long as, two transmissions do not use the same edge at the same time.case k is not bounded the model is called all-port line model.this paper, we extend Cohen's work [6], that handles the all-port line model.