Patent ID: 7526200
Filing Date: 2009-04-28
Classification: H04B,H04J

Abstract:
1. An optical transmission apparatus comprising: a memory for storing a time when each optical transmitter starts to transmit an optical signal; optical transmitters for transmitting optical signals; first monitor units for monitoring optical signals from the optical transmitters; a multiplexer for multiplexing the optical signals from the optical transmitter into a multiplexed signal; a second monitor unit for monitoring each optical signal which is multiplexed in the multiplexed signal from the multiplexer; and a processing unit for detecting an overlap in wavelength of transmitted optical signals according to a result of monitoring of the first and the second monitor units; wherein the processing unit determines which one of the optical transmitters whose time is stored in the memory has a time which is nearest to the time when the overlap was detected as an indication of a failure of the one of the optical transmitter.