Star data network with logical ring function preferably using token access

Star data network with logical ring function utilizing token access, including line concentrators with a plurality of bypass switching means each arranged for a corresponding link to a node in the data network, wherein each of said links comprises at least one transmission line, and wherein each of said bypass switching means is provided with an active signal processing means having first and second signal sides, said active signal processing means being adapted for superimposing on said first signal side a first incoming and a first outgoing signal on a single transmission line in said corresponding link, and on said second signal side for smoothing out a second incoming signal's contribution to a second outgoing signal, said first incoming and first outgoing signals on said first signal side corresponding to said second outgoing and second incoming signals on said second signal side, respectively, said single transmission line in said corresponding link being connected to said node via another signal processing means with a function corresponding to the function of said active signal processing means.