Abstract: A system (400), in its receiver aspect (e.g. 402), interconnects a terminal link (451) to either a first autonomous link (421) or a second autonomous link (431) depending upon the error conditions on the first and second links. The second link redundantly propagates the same data stream as the first link both in Extended Superframe Format (ESF) as generated in a transmitter (401) of the system. The two independent data streams are aligned in the receiver to compensate for the propagation delay difference between these two links. A predetermined number of first and second ESF superframes are stored in buffers during calculation of logic errors, if any, in each of the ESF superframes using the check data in each ESF superframe.