Abstract: A process is disclosed for frame synchronization in a time division multiplex system which, while ensuring a high degree of synchronization reliability, requires only a small transmission capacity. In accordance with the invention, before a synchronous state is reached, a synchronization alarm (SA=1) is given and the recognition of two consecutive synchronizing words (100010) defines the beginning of a test period (P). If synchronizing words (100010) are constantly received during this test period (P), the synchronization alarm (SA=1) is disconnected. If only one single synchronizing word (100010) is not recognized during the test period (P), the synchronization alarm continues. Commencing from the synchronous state, the synchronization alarm is given if a plurality of synchronizing words are not recognized (FIGS. 3 to 6).

Abstract: A method is disclosed for transmitting data between two time multiplex systems via a joint or common transmission path. Bit flows output by two time multiplex systems at the transmitter side are chronologically bit-wise interlaced with the aid of a diplexer at the transmitter side and are then reassembled into two bit flows by a diplexer at the receiver side of the time multiplex systems. The bit flows of the first and second time multiplex systems are defined by frames with first and second synchronization words, respectively. At the beginning of transmission, the two receiver side systems are adjusted to the first synchronizaton word. After recognizing the first synchronization word in one of the receiver sides the correct assignment is produced for the bit flows to the two multiplex systems.

Abstract: For use in connection with apparatus for determining the distortion characteristic of a data transmission path, a circuit arrangement is described for varying the phase of a reference signal against which the transmitted signal is compared in the receiver. A synchronizing device operates to produce a lag or lead in the pulse output of a timing generator, as a function of lagging or leading distortion. The synchronizing device is designed to operate according to a rectangular control characteristic so that the measured error values always relate to identical phase shifts in the reference signal.