Abstract: Star data network with logical ring function preferably utilizing token access, including a line concentrator with a plurality of bypass switches each arranged for its respective link in a node in the data network. Each bypass switch in the concentrators is provided with a preferably active signal processing element adapted on one signal side for superimposing an incoming and outgoing signal on the same transmission line in the link and on its other side for smoothing out the incoming signals contribution to the outgoing signal, and in that the transmission line in the link is connected to the node via a preferably passive signal processing element with a function corresponding of the function of the preferably active signal processing element, the transmission line preferably being a coaxial cable installed in an earlier terminal network.