Emilio Hugues-Salas

Next generation elastic optical networks: The vision of the European research project IDEALIST

In this work we detail the strategies adopted in the European research project IDEALIST to overcome the predicted data plane capacity crunch in optical networks. In order for core and metropolitan telecommunication systems to be able to catch up with Internet traffic, which keeps growing exponentially, we exploit the elastic optical networks paradigm for its astounding characteristics: flexible bandwidth allocation and reach tailoring through adaptive line rate, modulation formats, and spectral efficiency. We emphasize the novelties stemming from the flex-grid concept and report on the corresponding proposed target network scenarios. Fundamental building blocks, like the bandwidth-variable transponder and complementary node architectures ushering those systems, are detailed focusing on physical layer, monitoring aspects, and node architecture design.

Software defined networking (SDN) over space division multiplexing (SDM) optical networks: features, benefits and experimental demonstration

We present results from the first demonstration of a fully integrated SDN-controlled bandwidth-flexible and programmable SDM optical network utilizing sliceable self-homodyne spatial superchannels to support dynamic bandwidth and QoT provisioning, infrastructure slicing and isolation. Results show that SDN is a suitable control plane solution for the high-capacity flexible SDM network. It is able to provision end-to-end bandwidth and QoT requests according to user requirements, considering the unique characteristics of the underlying SDM infrastructure.

Archon: A Function Programmable Optical Interconnect Architecture for Transparent Intra and Inter Data Center SDM/TDM/WDM Networking

This paper reports all-optical, function programmable, transparent, intra- and inter-data center networking (DCN) using space and time-division multiplexing (SDM/TDM) within data centers and wavelength division multiplexing (WDM) between data centers. A multielement fiber is used for SDM transmission to provide a large quantity of optical links between the top-of-racks (ToRs) and the function programmable cluster switch. Beam-steering large-port-count fiber switches, used as central cluster switches and intercluster switch, provide a single hop optical circuit switching solution, and also enable network function programmability for DCN to support variable traffic patterns and different network functions. A TDM switch as a plug-in function provides intra-cluster communication with variable capacity and low latency. The flat-structured intra data center architecture, with a circuit-switched SDM and TDM hybrid network enables scalable, large-capacity and low-latency DCN communication. In addition, all-optical ToR-to-ToR inter-DCN is realized through metro/core networks. A highly-nonlinear fiber based all-optical SDM-to-WDM converter transfers three SDM signals to three-carrier spectral superchannel signals, which are transmitted to the destination DCN, through the metro/core networks. The all-optical ToR-ToR cross-DCN connections enable the geographically distributed DCNs to appear as one Big Data center.

Field Experiments With a Grooming Switch for OTDM Meshed Networking

Field experiments of 42.7/128.1 Gb/s wavelength-division multiplexed, optical time-division multiplexed (WDM-OTDM) transmultiplexing and all-optical dual-wavelength regeneration at the OTDM rate are presented in this paper. By using the asynchronous retiming scheme, we achieve error-free bufferless data grooming with time-slot interchange capability for OTDM meshed networking. We demonstrate excellent performance from the system, discuss scalability, applicability, and the potential reach of the asynchronous retiming scheme for transparent OTDM-domain interconnection.

Next generation optical nodes: The vision of the European research project IDEALIST

As traffic demands become more uncertain and newer services continuously arise, novel network elements are needed to provide more flexibility, scalability, resilience and adaptability to todays optical networks. Considering these requirements, within the European project IDEALIST the investigation of elastic optical networks is undertaken with special focus on next generation optical node architectures. As an evolution of existent ROADMs and OXCs, these optical nodes will establish a new paradigm in which the network requirements will be efficiently addressed considering various emerging dimensions. In this article, we describe the drivers, architectures, and technologies that will enable these novel optical nodes. In addition, multivendor traffic interoperability, optical defragmentation, and node cascadability are also described as considerations in the node design.

On the filter narrowing issues in elastic optical networks

This paper describes the problematic filter narrowing effect in the context of next-generation elastic optical networks. First, three possible scenarios are introduced: the transition from an actual fixed-grid to a flexi-grid network, the generic full flexi-grid network, and a proposal for a filterless optical network. Next, we investigate different transmission techniques and evaluate the penalty introduced by the filtering effect when considering Nyquist wavelength division multiplexing, single side-band direct-detection orthogonal frequency division multiplexing, and symbol-rate variable dual polarization quadrature amplitude modulation. Also, different approaches to compensate for the filter narrowing effect are discussed. Results show that the specific needs per each scenario can be fulfilled by the aforementioned technologies and techniques or a combination of them, when balancing performance, network reach, and cost.

DORIOS: Demonstration of an all-optical distributed CPU, memory, storage intra DCN interconnect

We show an all-optical ultra-low latency server-to-remote memory/storage data center interconnection, exploiting programmable, flexible, bi-directional and data-rate transparent 4×16 Spectrum Selective Switches and supporting elastic WDM/TDM services using fast nanosecond tunable lasers.

Field trial of WDM-OTDM transmultiplexing employing photonic switch fabric-based buffer-less bit-interleaved data grooming and all-optical regeneration

We report, for the first time, a field trial of a novel 42.7Gbps/128.1Gbps WDM/OTDM grooming node, and confirm node interoperability and the data integrity of asynchronous retiming.

Secure NFV Orchestration Over an SDN-Controlled Optical Network With Time-Shared Quantum Key Distribution Resources

Quantum key distribution (QKD) is a state-of-the-art method of generating cryptographic keys by exchanging single photons. Measurements on the photons are constrained by the laws of quantum mechanics, and it is from this that the keys derive their security. Current public key encryption relies on mathematical problems that cannot be solved efficiently using present-day technologies; however, it is vulnerable to computational advances. In contrast QKD generates truly random keys secured against computational advances and more general attacks when implemented properly. On the other hand, networks are moving towards a process of softwarization with the main objective to reduce cost in both, the deployment and in the network maintenance. This process replaces traditional network functionalities (or even full network instances) typically performed in network devices to be located as software distributed across commodity data centers. Within this context, network function virtualization (NFV) is a new concept in which operations of current proprietary hardware appliances are decoupled and run as software instances. However, the security of NFV still needs to be addressed prior to deployment in the real world. In particular, virtual network function (VNF) distribution across data centers is a risk for network operators, as an eavesdropper could compromise not just virtualized services, but the whole infrastructure. We demonstrate, for the first time, a secure architectural solution for VNF distribution, combining NFV orchestration and QKD technology by scheduling an optical network using SDN. A time-shared approach is designed and presented as a cost-effective solution for practical deployment, showing the performance of different quantum links in a distributed environment.

Experimental Demonstration of Multivendor and Multidomain EON With Data and Control Interoperability Over a Pan-European Test Bed

The operation of multidomain and multivendor EONs can be achieved by interoperable sliceable bandwidth variable transponders (S-BVTs), a GMPLS/BGP-LS-based control plane, and a planning tool. The control plane is extended to include the control of S-BVTs and elastic cross connects, which combine a large port-count fiber-switch (optical backplane) and bandwidth-variable wavelength-selective switches, enabling the end-to-end provisioning and recovery of network services. A multipartner testbed is built to demonstrate and validate the proposed end-to-end architecture. Interoperability among S-BVTs is experimentally tested between different implementations. In this case, transponders are configured using the proposed control plane. The achieved performance with hard-decision and soft-decision FECs using only the information distributed by the control plane is measured against the performance of the single-vendor implementation, where proprietary information is used, demonstrating error-free transmission up to 300 km.