Subcarrier Label Research Articles

Simultaneous erasure and rewriting of a subcarrier-multiplexed label in an all-optical label swapping scheme

A simplified all-optical label swapping scheme is proposed and experimentally demonstrated for all-optical packet switching. This scheme is based on the sub-carrier label multiplexing technique but it significantly reduces the cost and complexity of the label erasure and rewriting process at the intermediate nodes. This is accomplished using a shared interferometric filter for all wavelength channels to separate the payloads and labels as well as using gain-saturated RSOAs for label erasure and rewriting. Label swapping process is realized through re-assigning optical subcarriers to each output wavelength channel and rewriting the new label with RSOAs. The BER-free transmissions experimentally demonstrate the feasibility of the proposed scheme.

Optical labeling using carrier suppressed second harmonic subcarrier label

AbstractA carrier‐suppressed second harmonic subcarrier‐multiplexed labeling technique for optical label switching network is demonstrated. It provides frequency doubling for optical subcarrier label so that requirement for high bandwidth optical or electrical components can be reduced. The results of two‐span transmission of 10‐Gb/s payload with 1.244‐Gb/s subcarrier label show improved performance of the labeling technique. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1468–1470, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22418

All-Optical Label Swapping, Clock Recovery, and 3R Regeneration in 101-Hop Cascaded Optical-Label Switching Router Networks

This paper experimentally demonstrates the cascaded operation of an optical-label switching router for up to 101 hops, with optical label swapping, optical clock recovery, and 3R regeneration (re-amplification, reshaping, and retiming) at each hop. The optical label swapping utilizes all-optical payload/label separation and label rewriting with subcarrier label. An interferometer wavelength converter enables the reshaping function, while the synchronous modulation driven by the optically recovered packet clock performs the retiming function. The optical label swapping and 3R regeneration enable the packets to traverse a large number of hops while maintaining the signal quality to support the scalability of the optical-label switching network

Optical subcarrier labeling transparent to the payload format using carrier suppression technique

In this letter, we propose an optical subcarrier labeling technique that guarantees the transparency to the payload modulation format based on carrier suppression of the payload. We experimentally demonstrate transparent wavelength conversion based on four-wave mixing in a highly nonlinear fiber and subcarrier label insertion for a 10-Gb/s differential phase-shift keying payload and a 155-Mb/s amplitude shift keying subcarrier label with an overall penalty of 1.8 dB for the payload and 1.7 dB for the label.

BER Performance of All-Optical Subcarrier Label Swapping With 2R Regeneration

This paper proposes and demonstrates an all-optical subcarrier label swapping subsystem with 2R (reamplification, reshaping) optical regeneration and wavelength conversion. The experimental results show error-free operation with reshaping and regeneration leading to negative power penalty for signals with impaired signal-to-noise and extinction ratios. While the experiment was conducted on a single wavelength channel, a multiwavelength optical label switching system can incorporate this technique in parallel. The 2R regeneration in the all-optical label-swapping subsystem implies its viability in a scalable optical-label switching network.

All-optical subcarrier labeling based on the carrier suppression of the payload

We report on a new approach to all-optical subcarrier labeling based on sideband generation through carrier-suppression of the payload. The experimental transmission over 50-km standard fiber of a 10-Gb/s payload data multiplexed with a synchronized 1.25-Gb/s subcarrier label is carried out with less than 1-dB receiver power penalty, clearly demonstrating the feasibility of this sideband optical labeling scheme. The requirements to the modulation index and dc bias along with the limitation of the input extinction ratio are discussed.

Method for optical subcarrier label generation using carrier suppression technique

A novel method for optical subcarrier label generation is proposed and demonstrated with a dual-drive Mach-Zehnder modulator performing carrier-suppressed modulation. An optical signal consisting of a 10 Gbit/s payload and a 156 Mbit/s label was generated, and its performance was evaluated in a 50 km standard fibre transmission link.

A novel optical label swapping technique using erasable optical single-sideband subcarrier label

To support optical multiprotocol label switching (MPLS) technology in an optical network, we have demonstrated subcarrier label swapping in a 96.2-km, three-node experiment, by using optical single-sideband modulation and an optical notch filter. At each intermediate switching node, an old subcarrier label can be suppressed by 25 dB, while the burst-mode 2.5-Gb/s payload experienced only 2-dB power loss.

All-optical label swapping with wavelength conversion for WDM-IP networks with subcarrier multiplexed addressing

We report the first demonstration of all-optical label swapping with wavelength conversion and subcarrier multiplexed addressing for WDR IP. This demonstration utilizes a module which is based on cascaded semiconductor optical amplifier wavelength converters that perform the functions of label removal, label rewriting, payload 2R regeneration and double sideband subcarrier label regeneration. Replacement of double-sideband subcarrier labels on a hop-by-hop basis addresses the problem of dispersion induced fading in a multihop fiber network. A direct detection subcarrier receiver is used to recover the label. Switching over four wavelengths covering 16 nn is demonstrated with noninverting wavelength conversion of 2.5-Gb/s payloads and burst mode recovery of 10-Mb/s labels. BER measurements of better than 10/sup -9/ for the wavelength-converted payload and rewritten labels at all wavelengths are presented.