Patent ID: 7184661

Claim:
A transmission apparatus for use in a communication network to which a plurality of transmission equipment are connected through a plurality of transmission lines transmitting synchronous multiplex signals, wherein overhead for supervision, maintenance and operations of transmission equipment and transmission lines is added to a payload in which main signals are multiplexed, said transmission apparatus comprising: an optical transmitter that transmits said synchronous multiplex signals to said transmission lines, an optical receiver that receives said synchronous multiplex signals from said transmission lines, an overhead processing unit that adds said overhead to said payload and extracts said overhead out of said synchronous multiplex signals from said optical receiver, a cross connect unit that divides and multiplexes said payload inputted from said overhead processing unit, switches output routes of said payload for transmission to either of said transmission lines, and outputs to the overhead processing unit again, a clock unit that supplies a clock to at least said cross connect unit, an equipment supervision unit that supervises at least said cross connect unit and said clock unit and outputs an instruction signal based upon the result of the supervision, a switching control unit that controls switching of the transmission lines so that, being based upon said instruction signal and said overhead, said cross connect unit, said overhead processing unit and said optical transmitter, said synchronous multiplex signals may be transmitted to either of said transmission lines properly; and wherein upon said equipment supervising unit detecting a condition in which obstacles have occurred in more than one group in at least either of said cross connect unit and said clock unit, said equipment supervision unit inserts information about said obstacles in said instruction signal, and said switching control unit into which said instruction signal is inputted enables said overhead processing unit and the optical transmitter to output isolation instruction information to said transmission line.