Investigation on the Signal Misalignment in Subcarrier Multiplexed Optical Label Swapping Routers: An Experimental Verification

This paper presents a theoretical and experimental evaluation of the subcarrier-multiplexing label and payload alignment in an optical label-swapping router; optical packets, which are composed of label and payload, are transmitted from the edge router to the core router, where the labels are processed, and the new labels are reassembled to the payload in a synchronized operation. True delays of the signals in the core router are precisely evaluated, and synchronization aspects are studied in detail. For the first time, to our knowledge, the experimental verification allows the evaluation of the delay-tolerance range in the process of coding the baseband label onto the optical packet without affecting the normal operation of the router. Key issues found in the core-router implementation are thoroughly described throughout this paper.