Spectral efficient DWDM optical label generation and transport for next generation internet

Abstract

A novel optical carrier suppression and separation (OCSS) technique is used to generate spectral efficient DWDM optical labels and payload. The advantages and disadvantages of using different techniques to generate optical labels are compared. The transmission performance of the optical label and payload is experimentally and numerically investigated. These numerical and experimental results show that the optical label and payload generation and transport using the OCSS technique can be applied to wide-area metro and core network. subcarrier multiplexing technique results in interference be- tween the two label sidebands when detected by a square-law device. In the fixed-rate serial technique, bit-serial labels are used. Serial labels are placed at the head of each packet, buffered by optical guard-bands that facilitate label removal and reinsertion. Fixed-rate serial labeling requires strict synchro- nization between the payload and label, which is exceedingly difficult to achieve in real optical data routing networks. In orthogonal modulation schemes, the label or payload suffer a diminished extinction ratio (ER) due to physical limitations. This lowered ER obviously limits signal transmission distance, excluding such a solution from use in core optical networks. This paper investigates the performance of optical carrier suppression and separation (OCSS) techniques for payload and label generation in optical systems and networks. Optical carrier suppression techniques along with high performance optical components are used to demonstrate the novel optical label and payload generation method, OCSS (10). The optical components employed, such as fiber Bragg gratings (FBGs), arrayed wave-guide gratings (AWG's) and narrow bandwidth optical inter-leavers are becoming evermore commercially viable for use in real systems. The remainder of this paper is organized as follows: In Sec- tion II, details of the OCSS principle are analyzed and different techniques to generate optical labels and payload are compared. Section III describes the transmission experiments for single channel payload and label over 300-km single-mode fiber (SMF-28) and eight-channel DWDM payload and label with 0.4-nm channel spacing over 200-km SMF-28. The numerical simulation results for eight-channel DWDM are shown in Sec- tion IV. In Section V we show an optical network experiment with three nodes demonstrating that our method can be applied in practical optical networks of the future. The conclusion is given in Section VI.