OFC’10 Summary ---Core Networks Part III

1. OFC’10 Summary ---Core Networks Part III Avishek Nag

2. OFC’10 Technical Sessions on Core Networks OMM: Path Computation and Routing I OMU: Path Computation and Routing II OThP: High Speed Routing OTuG: Network Architecture and Control I OWR: Network Architecture and Control II OWH: Restoration and Protection OTuK: Quantum Communication Symposium II: Networking OWM: Advanced Networking Technologies OWY: Energy Efficiency and Next-Generation Networks

3. OFC’10 Technical Sessions on Core Networks OTuK: Quantum Communication Symposium II: Networking OWM: Advanced Networking Technologies OWY: Energy Efficiency and Next-Generation Networks

4. NFOEC’10 Technical Sessions on Core Networks NTuA: Network Design NThA: Network Restoration NThE: Multi-Layer Networks NMD: Converged Networks NWA: Advanced Network Applications NThF: Next Generation Optical Network Technology NMB: Migrating to 100G NTuB: High Speed Network Technologies NWC: Network Testing and Characterization

5. Quantum Communications Symposium II Demonstrates coexistence of classical and quantum signals for quantum key distribution in a DWDM reconfigurable networking environment using a ROADM. shows how the limiting noise mechanism can depend on the link configuration. Demonstrates the first 10GHz clock-rate, differential-phase-shift-keyed quantum key distribution system on a 10Gb/s multi-user WDM-PON network. A dual feeder fiber scheme is used to reduce spontaneous Raman scattering-induced inter-channel cross-talk.

6. Quantum Communications Symposium II A solution for high-speed QKD system equipped with low loss receivers with high visibility, highly efficient photon detectors with small dark count probability, and a stable clock synchronization system is proposed. A hierarchical metropolitan quantum cryptography network upon the inner-city commercial telecom fiber cables is reported in this paper.

7. Quantum Communications Symposium II Proposes a simple method for passive preparation of decoy states in quantum key distribution with coherent light. It involves linear optics together with a photo-detector. The performance is comparable to the active decoy schemes.

8. Advanced Networking Technologies Experimental demonstration of a novel sensing system based on FBG sensors with comprehensive self-healing capability in a mesh-ring-based topology by utilizing the FSR and periodic filtering characteristics of the AWG. Simultaneous 3 × 10-Gbps error-free photonic transmissions with clear eye-openings are demonstrated in the 1-μm, C-, and L-wavebands by using an ultrabroad-waveband photonic transport system comprising a 3.3-km-long holey fiber transmission line.

9. Advanced Networking Technologies A hardware accelerated QoT estimation tool used in the DICONET impairment-aware optical network. Performance evaluation is given by examining different network scenarios in terms of network size and number of wavelengths. An FPGA-based buffer management hardware with 8 input ports, which implements a parallel and pipeline mechanism to support over-200-Mpacket/s/port asynchronous variable-length optical packet switching, is proposed.

10. Advanced Networking Technologies

11. Energy Efficiency & Next Generation Networks Review of key advanced technologies for next-generation optical networking. Advanced physical layer techniques for 100 Gb/s transmission, packet-based transport in core and metro networks, and novel candidate architectures for next-generation optical access. Based on traffic models the energy consumption of adaptive networks is compared to networks with constant power consumption.

12. Energy Efficiency & Next Generation Networks Evaluation of energy efficiency of mixed-line-rate (MLR) optical networks. A comparative study of energy efficiency of MLR and single-line-rate (SLR) networks shows that MLR is more energy efficient than SLR networks. Proposes AWG based optical switching fabric architectures and demonstrates their energy efficiency over electronic backplanes and interconnects

13. Energy Efficiency & Next Generation Networks Energy consumption of electronic burst switching is modeled and compared to electronic packet switching in the network core and edge. It is shown that burst switching can provide significant energy savings relative to packet switching. Energy-efficient traffic grooming scheme for promoting greener optical networks. The scheme considers a modular node architecture, reuses already active components during request allocations, and conserves total energy consumption in the network.

14. Migration to 100G Report on the transmission of a 107Gb/s DPSK-3ASK optical channel over 335km fiber (SSMF). DPSK-3ASK is targeted to meet the requirements of a metro network. Spectrally-efficient 100Gb/s coherent transponder technology in carrier networks can yield substantial CAPEX and OPEX savings. This paper discusses these economic gains and how a carrier can maximize their return on optical transport investment.

15. Migration to 100G Propose an approach that first designs each ROADM-to-ROADM section independently to minimize the OSNR penalty in each section. Then the whole network is examined to see if adding ROADM sites to long sections would be beneficial for reducing the number of regenerations in all possible paths. Operational efficiency improvements of optical networks enabled by digital coherent receivers are discussed in view of reliability, agility, performance and reduced operational complexity. Several specific technologies are briefly introduced to deliver some more insight.

16. High Speed Network Technologies Study of high bit-error tolerant frame/lane alignment for 100 Gb/s multi-lane transmission with advanced modulation formats. Bit-error allowance/correction for frame/lane alignment improves the bit-error tolerance up to BER of 10^-2 Recently revised ITU-T G.709 defines a container for 100 Gbps signals called an OTU4. This paper highlights some of the reasons the OTU4 bit rate, frame structure, and mapping scheme were chosen.

17. High Speed Network Technologies 40G OTU3 performance results for Continuously-Interleaved concatenated BCH (CI-BCH) FEC, demonstrating best-in-class performance for a 7% overhead hard-decision FEC and offers option to tradeoff coding gain for reduced FEC decode latency. Constant envelope formats including CPM may reduce the impact of nonlinear impairments arising from intensity variations and the associated nonlinear phase noise. The advantages of CPM versus QPSK are quantified and possible deployment opportunities are identified.

18. High Speed Network Technologies Reach estimations for several variable-bitrate OFDM schemes are presented and discussed in the framework of a transparent EU core network scenario. 44% reduction on OE interfaces is found compared to a fixed-bitrate 40Gb/s network.

19. Network Testing and Characterization A tunable modulated broadband source and narrow-bandwidth filter are used to measure chromatic dispersion, group-delay ripple, and pass-band shape of DWDM-network light paths. This new method is simple and suitable for in-service measurements. Proposes a novel in-service optical reflectometry based on the correlation detection using a pseudo-noise signal superimposed on the downstream signal. Using the proposed technique, in-service monitoring of TDM and WDM PONsis demonstrated

20. Network Testing and Characterization Demonstration of enhanced sensitivity of a commercial OTDR by employing novel bidirectional analysis techniques. The method is applicable to measurements of cabled fiber where fluctuations in local mode field diameter are due to factory variations. Demonstration of an energy-autarkic FTTx monitor. A special protocol and sophisti-cated hardware reduce the electrical operating power to 0.7μW, which can be delivered by an optical supply signal of only 5μW/monitor at a separate wavelength.

21. Network Testing and Characterization This paper presents area-optimized implementations of Galois Field multipliers that exploit the unique programmable logic cells in the Xilinx FPGA, enabling a 100 Gb/s EFEC block with significantly lower footprint within an optical transport FPGA. A novel four-tone probe signal is used to measure end-to-end residual chromatic dispersion in single 50-GHz DWDM channels of a long-haul ROADM network while transmitting more than 30 live signals in neighboring channels.

22. Conclusion • Trends… • Quantum key distribution in optical networks • Green networks • Advanced networking paradigms • Migration towards high bit rates and associated technologies viz., OFDM, coherent receiver… • Real time performance monitoring