Patent ID: 7639677

Claim:
An optical transponder having a switching function, said optical transponder comprising: a plurality of optical-to-electrical (O/E) or electrical-to-optical (E/O) converters for O/E or E/O conversion of signals from or to a plurality of optical fiber links; a switch for changing a data path of an input tributary signal from a plurality of channels being transmitted over the plurality of optical fiber links; an STM-64/OC-192 mapper/demapper for mapping the tributary signal, which has been switched to a different data path by the switch, to an STM-64/OC-192 signal or for demapping the STM-64/OC-192 signal to the tributary signal; and a transmission delay time compensator for compensating for a differential delay caused by transmitting a plurality of said STM-64/OC-192 signals over various links among the plurality of optical fiber links when each said STM-64/OC-192 signal is demapped to a corresponding tributary signal; wherein said transmission delay time compensator is arranged for (i) buffering an earlier-arrived STM-64/OC-192 signal among the STM-64/OC-192 signals that are transmitted via the various optical links, (ii) reading the buffered, earlier-arrived STM-64/OC-192 signal upon arrival of a later-arrived STM-64/OC-192 signal among the STM-64/OC-192 signals, and (iii) recombining the later-arrived STM-64/OC-192 signal with the buffered, earlier-arrived STM-64/OC-192 signal to thereby compensate for said differential delay; and wherein said switch is coupled between the converters and the STM-64/OC-192 mapper/demapper, to be downstream of said converters and upstream of said STM-64/OC-192 mapper/demapper.