| 摘要 |
A communication system includes a head end, a plurality of nodes, and a pair of transmission lines forming respective rings for carrying signals in opposite directions between said nodes to provide full duplex operation. A switch is located at each node for selectively breaking the continuity of each ring. The switch is normally open and the switches at the remaining said nodes are normally closed so as to divide the rings into two dynamically changeable logical segments. In the envent of a line break, the normally open switch closes, and one of the other switches between the break and the head end opens so that the dynamically changeable segments terminate on either side of the break. Node communications terminate at the head end. Node communication services switch direction of transmission to the head end based on a determination of a valid transmission path to the head end. |
