| 摘要 |
<p>PURPOSE:To reconstitute a transmission route quickly by discriminating a fault of a transmission line with a synchronous error discrimination by consecutive confirmation of forward and backward protection and the conversion discrimination of an error rate of total flag bit number to an instantaneous flag error or an error rate of all bits to a coded error. CONSTITUTION:Forward backward protection means 3, 4 detect a synchronous error of each system and control information demultiplex means 5, 6 output respectively loopback information and NG information. Transmitters 33, 34 detecting a fault of a transmission line 36a or 38b multiplex transmission line fault information with loopback information processed by itself and stop the transmission to urge loopback. The stop of transmission is implemented for a prescribed time only and a host device or a subsequent device urged of the loopback uses a synchronizing error detection circuit to discriminate the transmission line fault to apply loopback processing. Thus, in the case of protection of the loop system in a digital relay system, the reconstitution of the transmission route is quickened.</p> |
