FRAME PSEUDO SYNCHRONIZATION PREVENTING SYSTEM

摘要

PURPOSE:To prevent the occurrence of frame pseudo synchronization or unestablished synchronization resulting from the appearance of a signal series whose pattern equal to a frame pattern at the outside of the range of the frame pattern in a signal of multi-frame structure. CONSTITUTION:A selector 3(13) used to insert a random pattern is provided to a transmitter side of a line interface 1(11) and a control bit used to inform established frame synchronization of a receiver side of a concerned station to a destination is defined in the frame pattern. The receiver side is provided with a control bit detector 6(16), and a control signal for the selector 3(13) is generated from an output of the control bit detector 6(16) and an output of a frame synchronization circuit 5(15) and the signal is used to allow the selector 3(13) to be thrown to the position of sending usual transmission data only when frame synchronization at both line interfaces opposite to each other is established.