Error correction transmission apparatus

Abstract

An encoder adds an identifier, being different when the coding should be done or not, into a predetermined location in an original signal, while a decoder reads out the identifier added and detects the condition of coding, so as to decide the execution (ON) of the decoding process to be done or not, automatically. Further, in each of the encoder and the decoder, there is provided a delay output portion, which provides an output treated with only a specific delay but not executing the coding/decoding thereon, separately from a coding process portion or a decoding process portion, wherein a selection can be made, at which one of the signals from the respective process portions and the delay output portion should be outputted, by a setup in an outside operation system with use of a selector.

What is claimed is:  
     
         1 . A transmission apparatus, comprising: 
 a first optical signal receiver which receives a first optical signal transmitted from a first transmission path;    a second optical signal receiver which receives a second optical signal transmitted from a second transmission path;    a first optical signal transmitter which transmits a third optical signal onto a third transmission path;    a second optical signal transmitter which transmits a fourth optical signal onto a fourth transmission path;    an interface for distribution system; and    a cross connect switch which exchanges electric signals from said first and second optical signal receivers and said interface for distribution system, and which sends out them into said first or second optical signal transmitter, or into said interface for distribution system, wherein,    a decoder for error correcting code of said first or second optical signal receiver and an encoder for error correcting code of said first or second optical signal transmitter are independently controllable for each.