Optical Label Swapping Research Articles

High-Speed Optical Packet Processing Technologies for Optical Packet-Switched Networks

Asynchronous optical packet switching (OPS) is a promising solution to support the continuous growth of transmission capacity demand. It has been, however, quite difficult to implement key functions needed at the node of such networks with all-optical approaches. We have proposed a new optoelectronic system composed of a packetby-packet optical clock-pulse generator (OCG), an all-optical serial-to-parallel converter (SPC), a photonic parallel-to-serial converter (PSC), and CMOS circuitry. The system makes it possible to carry out various required functions such as buffering (random access memory), optical packet compression/decompression, and optical label swapping for high-speed asynchronous optical packets.

High-speed optical FSK modulator for optical packet labeling

We described a novel optical label swapping (OLS) technique for optical packet systems using frequency-shift-keying (FSK) optical labeling. High-speed optical FSK signal can be generated by using an external FSK modulator consisting of four optical phase modulators. The FSK modulator was based on optical single-sideband (SSB) modulation technique, and comprised of traveling-wave electrodes for high-speed frequency switching. We demonstrate 10 Gbps FSK transmission, and simultaneous modulation by FSK and intensity modulation (IM). OLS using double-sideband modulation was also demonstrated, where this technique can be used for a bundled wavelength-domain-multiplexing (WDM) channels without using an array of pumping light sources.

In-Band Time-to-Live Signaling System for Combined DPSK/SCM Scheme in OLS

We propose and validate experimentally a time-to-live (TTL) signaling system for an optical label swapping scheme based on 10-Gb/s differential phase-shift-keying (DPSK) packets and with 100-Mb/s subcarrier multiplexing (SCM) label. The proposed scheme allows fast packet discarding by using a 3-GHz subcarrier tone. DPSK payload has only a 2.4-dB power penalty at 10/sup -9/ bit-error rate after superimposing the SCM and TTL labeling signal.

Optical Label Swapping in a Packet-Switched Optical Network Using Optical Carrier Suppression, Separation, and Wavelength Conversion

We have experimentally demonstrated for the first time how to realize label swapping in an optical network where the label and payload are generated using optical carrier suppression and separation. The bit-error-rate performance for both the payload and label are evaluated at different nodes in this optical network.

Simultaneous Optical Label Erasure and Insertion in a Single Wavelength Conversion Stage of Combined FSK/IM Modulated Signals

We report on optical label swapping of combined frequency-shift keying/intensity modulation (FSK/IM) modulated signals by using a single wavelength conversion stage based on a semiconductor optical amplifier Mach-Zehnder interferometer. Simultaneous FSK label erasure and insertion at a bit rate of 156 Mb/s is successfully achieved for a 10-Gb/s IM payload with transmission over two spans of 40-km standard single-mode fiber.

Demonstration of all-optical packet switching routers with optical label swapping and 2R regeneration for scalable optical label switching network applications

This paper investigates comprehensive operation and experimentation of an all-optical packet switching router with optical label swapping and reamplification and reshaping (2R) regeneration, capable of multihop operation and Internet protocol (IP)-client interoperability. In particular, the experiment demonstrates successful packet switching and transport up to 11 hops with 10/sup -9/ bit-error rate and error-free up to four hops. Furthermore, this paper demonstrates the optical label switching (OLS) core router and edge routers working together to support IP-client-to-IP-client packet transport and switching across the optical label switching network. The edge router generates an optical label based on the IP header content of the packet and generates an optical label encoded packet, which subsequently ingresses into the OLS network. The optical label switching router (OLSR) forwards the packet with all-optical label swapping at each hop with 2R regeneration. The 2R regeneration leads to an experimentally measured negative penalty and a successful experimental demonstration of multihop cascaded OLSR operation with the edge routers interfacing with IP clients. The successful IP-client-to-IP-client packet forwarding via the edge routers and the cascaded multihop OLSR with all-optical label swapping indicate the viability of OLS in the scalable and transparent IP-over-optical Internet.

Performance of a SOA-MZI wavelength converter for label swapping using combined FSK/IM modulation format

This paper presents a theoretical and experimental assessment of the performance of a wavelength converter based on semiconductor optical amplifiers (SOA) in a MZI configuration for optical label swapping. The optical labeling of the signal is based on an FSK/IM combined modulation format for the header/payload, respectively. Experimental results are presented for a signaling scheme with payload data at 10 Gbit/s and an FSK label at 312 Mbit/s. Simulation results and measurements of the chirp properties of converted signals operating at data rates of 2.5 and 10 Gbit/s are presented. Conclusions and design guidelines are presented regarding the implications of the wavelength converter performance on the quality of the label and payload signals for fast packet/burst forwarding in optically labeled switched networks.

All-optical label swapping networks and technologies

All-optical label swapping is a promising approach to ultra-high packet-rate routing and forwarding directly in the optical layer. In this paper, we review results of the DARPA Next Generation Internet program in all-optical label swapping at University of California at Santa Barbara (UCSB). We describe the overall network approach to encapsulate packets with optical labels and process forwarding and routing functions independent of packer bit rate and format. Various approaches to label coding using serial and subcarrier multiplexing addressing and the associated techniques for label erasure and rewriting, packet regeneration and packet-rate wavelength conversion are reviewed. These functions have been implemented using both fiber and semiconductor-based technologies and the ongoing effort at UCSB to integrate these functions is reported. We described experimental results for various components and label swapping functions and demonstration of 40 Gb/s optical label swapping. The advantages and disadvantages of using the various coding techniques and implementation technologies are discussed.