Ricard Vilalta

• PhD
• Senior Researcher at CTTC Catalan Telecommunications Technology Centre

This paper explores the potential of network digital twins (NDTs) in networking (both IP Ethernet networks and optical transport networks), highlighting their integration with cloud-native software-defined networking (SDN) controllers and intent-based networking enabled by generative artificial intelligence (GenAI). The proposed framework represent...

This paper, an extended version of a tutorial presentation given at OFC’24, aims to provide an overview of key aspects in the design and development of a control plane for multiband over spatial division multiplexing optical networks following software defined networking principles. The tutorial will address system design considerations such as the...

Effective management of end-to-end 6G network services is crucial, with peak capacity requirements for 6G transport connections expected to exceed 1 Tb/s. As demand for high bandwidth rises, there is a growing necessity for high-capacity optical fiber links, including ultra-wideband (UWB) and multiple fiber links within the network. Scaling up to a...

In cross-border mobility scenarios, interactions between mobile network operator (MNO) infrastructures and multi-access edge computing (MEC) systems across international borders are required at both the control and data planes to provide seamless and uninterrupted services to users transitioning between two MNOs. However, the exchange of informatio...

The emergence and consolidation of increasingly programmable optical devices such as transceivers, amplifiers, multiplexers, or ROADMs—which allow their remote configuration and control by adopting software-defined networking principles such as model-driven development—is enabling the evolution toward gradually more autonomous networks. Such networ...

Research on vehicle-to-everything (V2X) is attracting significant attention nowadays, driven by the recent advances in beyond-5G (B5G) networks and the multi-access edge computing (MEC) paradigm. However, the inherent heterogeneity of B5G combined with the security vulnerabilities of MEC infrastructure in dynamic V2X scenarios introduces unpreceden...

As the fifth generation (5G) mobile communication systems are commercially deployed, they bring new services, enhance user experiences, and offer various opportunities to different industries. Despite its advancements, 5G encounters several challenges. To tackle these issues, global industrial, academic, and standards organizations are actively res...

This paper presents an end-to-end transport SDN control system for packet (IP) and multi-granular (WDM/WBDM/SDM) optical networks for 6G transport. The dynamic routing and resource assignment combining wavelength, waveband, and spatial resources is also addressed.

This tutorial aims at presenting the key aspects in the design and development of control plane for Multi-Band over SDM optical networks following Software Defined Networking Principles. The tutorial will address system design considerations such as the systematic use of data modelling model driven development, will detail selected, industry adopte...

We present a hierarchical energy monitoring framework to systematically analyze energy consumption in computing, IP, and Optical networks. We demonstrated the framework on the laboratory testbed to validate the practicality and scalability.

A SDN controller based on TeraFlow is designed and implemented to control optical networks including parallel fibers a nd o ptical-band s witching. A n e xperimental validation is carried out with OpenConfig transponders and OpenConfig augmented multi-granular nodes.

This paper presents the architectural and data model extensions necessary to provide support for SmartNICs from SDN controller perspective. It later presents a use case for providing anomalous behaviour profiling support using the proposed extensions.

Transport network operators support diverse services for multiple tenants. Wavelength division multiplexing (WDM) and space division multiplexing (SDM) enable optical virtual networks by using spatial channels and virtualized devices on top of the optical transport network infrastructure. Integrating network function virtualization (NFV) and softwa...

The use of Network Digital Twins (NDT) in optical networks is a promising development that can improve network optimization, decision-making, and testing. The proposed architecture that utilizes SDN controllers to deploy NDTs presents a novel approach to achieving these benefits. The virtual representation of the physical optical network provided b...

The introduction of futuristic and challenging use cases of 5G and 6G communications will demand strict requirements in terms of high bandwidth and low latency. Optical backbone networks need to tackle these new network scenarios by offering highly efficient, flexible, and scalable technologies and solutions. In this context, elastic optical networ...

A trend in future networks (i.e., beyond 5G and 6G) is the increasing virtualization and disaggregation of networks (i.e., Open Radio Access Network, network function virtulization/software-defined networking, or disaggregated optical networks, among others). This trend leads to a multi-vendor situation appearing in the telco arena (i.e., hardware...

To support the pervasive digital evolution, optical network infrastructures must be able to quickly and effectively adapt to changes arising from traffic dynamicity or external factors such as faults and attacks. Network automation is crucial for enabling dynamic, scalable, resource-efficient, and trustworthy network operations. Novel telemetry sol...

We present P5; an event-driven policy framework that allows network operators to realize end-to-end policies on top of P4-based data planes in an intuitive and effective manner. We demonstrate how P5 adheres to a service-level agreement (SLA)by applying P4-based traffic engineering with latency constraints.

We demonstrate a scalable processing of OPM data using ML to detect anomalies in optical services at run time. A dashboard will show operational SDN controller metrics, raw OPM data, and the ML assessment results.

Disaggregation in optical networks is particularly relevant to be considered for the deployment of 5G services and towards the support of 6G. Particularly in the metro area network (MAN), this is especially crucial, as is the adoption of suitable photonic technologies enabling dense integration to design a sustainable network architecture. Furtherm...

This paper discusses the advantages and challenges of multiple architectures that consider the negotiation of inter-domain transport network slices using blockchain technologies. To this end, we presents results obtained using cloud-native ETSI TeraFlowSDN controller.

This demonstration showcases how TeraFlowSDN provides support for hierarchical control of multiple heterogeneous SDN domains (through IP, microwave and optical technologies). Different transport slices are offered with multiple SLAs and grouped to optimize resources.

A novel DRL solution for service provisioning over a cloud/EON stratum is presented. The benefit of DRL is that it can be adopted in different (unseen) EON topologies attaining better service blocking compared to traditional heuristics.

We experimentally demonstrate an SDN architecture for WDM VNTs to offload pass-through high bit-rate optical channels from overloaded ROADMs by provisioning spatial channels between the source and destination ROADM’s add-drop stages, and rerouting the optical channels.

Cooperative, Connected and Automated Mobility (CCAM) and Future Railway Mobile Communications System (FRMCS) use cases present strict requirements in terms of service end-to-end latencies, data-rates, reliability and service availability , posing challenges in the design of 5G network architectures for cross-border scenarios, where current roaming...

Due to the fact that the current variability of services is brought by the current networks and the new possibilities that will appear thanks to the near-future networks, Network Slicing has become one of the key elements to allow the co-existence of multiple computing and transportservices with different requirements (i.e., performance, security,...

This tutorial considers the evolution of software-defined networking (SDN) control for optical transport networks (OTNs) in disaggregated scenarios, focusing on its requirements and challenges when applied to “beyond 100G” networks, a term that jointly refers to the use of coherent technology, data rates beyond 100G, and the evolution of OTN standa...

We report the design of a TAPI SDN control plane for multi-band networks with externalized PLI-aware RMSA. We detail the architecture, data model extensions, algorithms and the implementation and validation in an emulated BT 22-ROADM network. © 2022 The Author(s) 1. Introduction Optical transmission exploiting multiple optical bands is the sole sol...

Maintaining a good quality of transmission (QoT) in optical transport networks is key to maintaining the service level agreement between the user and the service provider. QoT prediction techniques have been used to assure the quality of new lightpaths as well as that of the previously provisioned ones. Traditionally, two different approaches have...

Data center (DC) interconnection allows us to have optical transmissions between DCs directly connected to optical networks, avoiding the use of a packet-based infrastructure. Thanks to the use of next-generation pluggable coherent optics, it is possible to create connectivity services (CSs) across multiple optical transport domains. In this multi-...

We experimentally demonstrate a disaggregated metro area network that includes new photonic devices, node architectures, and sliceable bandwidth/bitrate variable transceiver, transmitting up to 8 × 11=88 spatial/spectral channels for a total capacity of 1.676Tb/s.

We experimentally demonstrate the dynamic reconfiguration o f W DM VNTs in response to SDM spatial channel failures. We present an SDN control architecture with gRPC-telemetry and analytics to detect failures and restore failed virtual WDM links

A deep reinforcement learning-based agent is presented to perform autonomous lightpath restoration upon a link failure event. The agent is evaluated against other heuristic algorithms under different traffic load and failure duration scenarios.

We propose an architecture to deploy Digital Twin Optical Networks (DTON), which provide a virtual representation of the physical optical network. DTON allow the assessment of specific behaviors before actual implementation in the physical network.

We demonstrate zero-touch device bootstrapping, monitoring, and L3-VPN service management using the novel TeraFlow OS SDN controller prototype. TeraFlow aims at producing a cloud-native carrier-grade SDN controller offering scalability, extensibility, high-performance, and high-availability features.

Unsupervised learning (UL) is a technique to detect previously unseen anomalies without needing labeled datasets. We propose the integration of a scalable UL-based inference component in the monitoring loop of an SDN-controlled optical network.

We propose and demonstrate a set of microservice-based security components able to perform physical layer security assessment and mitigation in optical networks. Results illustrate the scalability of the attack detection mechanism and the agility in mitigating attacks.

Network operators cannot change their footprint to upgrade the entire network to support SDN from scratch. Hence, network operators adapted the original SDN concept into a hybrid SDN approach to have a pragmatic, evolutionary, and economically viable solution. This article tests an SDN architecture based on a hierarchical structure of a Software-De...

Network operators have been dealing with the necessity of a dynamic network resources allocation to provide a new generation of customer-tailored applications. In that sense, Telecom providers have to migrate their BSS/OSS systems and network infrastructure to more modern solutions to introduce end-to-end automation and support the new use cases de...

Communication systems are used not only by voice or file exchange applications, but also by other types of applications due to the coexistence of multiple and different verticals. Each vertical has its own requirements in terms of key performance indicators (KPIs) for their applications. Mapping the verticals KPIs into network quality of service (Q...

This paper presents an experimental evaluation of network protocols for control and management of optical networks and optical network equipment as seen in current trends. This paper presents the YANG data modeling language and its associated RESTCONF/NETCONF protocols. Later, it details multiple data models used in optical networks, such as IETF T...

This paper presents a beyond 5G fronthaul network with dynamic beamforming and -steering. The proposed fronthaul solution deploys optical beamforming (OBF) by combining space division multiplexing (SDM), analogue radio-over-fiber (ARoF), and the novel optical beam forming network (OBFN) technologies. From the service management and orchestration (M...

Network slicing will permit offering to vertical customers tailored end-to-end logical networks in an on-demand fashion, on top of a common telecom infrastructure, achieving a Slices-as-a-Service (SlaaS) business model. This is possible due to the progressive introduction of network softwarization techniques, such as programmability and virtualizat...

This chapter provides an overview of potential network enhancements that can facilitate or improve the delivery of connected automated driving and connected road user services. The solutions presented expanded on infrastructure solutions such as slicing, software‐defined network, network function virtualization, and cloud radio access network to br...

Vehicle-to-everything (V2X) communications enable real-time information exchange between vehicles and infrastructure, which extends the perception range of vehicles beyond the limits of on-board sensors and, thus, facilitating the realisation of cooperative, connected, and automated mobility (CCAM) services that will improve road safety and traffic...

To meet the requirements of 5G high capacity optical metro networks, a programmable disaggregated multi-dimensional sliceable bandwidth/bitrate variable transceiver (S-BVT) is proposed. Specifically, transceiver multi-dimensionality is presented exploiting spatial, polarization, and spectral information as a solution to support network capacity and...

We experimentally demonstrate a 5G digital fronthaul network that relies on multi-adaptive and an autonomic control system for partially-disaggregated /. Transmission of 256-QAM 760.32 MHz radio signal is performed, with a total radio transmission capacity of 5.667 Gb/s. Digitized signal samples are carried as a 22.25 Gb/s data stream and transmitt...

Vehicles will be wirelessly connected in the future, and they will be able to exchange information with other vehicles and their surroundings for safer and more efficient driving. 5G communication systems have introduced advanced functionalities and radio solutions to support connected, cooperative, and automated mobility (CCAM) services with deman...

Future metro networks need to increase the transport capacity and improve the cost- and power-efficiency. These challenges are tackled by the EU-H2020 PASSION project exploiting dense photonic integration and cost-efficient optical technologies. Specifically, PASSION investigates a) modular sliceable bandwidth variable transceivers (S-BVTs) built u...

Internet service providers are shifting to an open, modern, software-based architecture that enables both new operating and business models. The target architecture is loosely coupled, cloud-native, data and artificial intelligence-driven, and relies on traffic engineering-related protocols to get the full potential of the network capabilities. The...

The full integration of an OAM function with a SDN controller to support autonomic networking capabilities within optical metro networks is presented. A devised Global Concurrent RSA algorithm to maximize connection restorability is experimentally evaluated.

We present a cloud-native architecture with a machine learning QoT predictor that enables cognitive functions in transport SDN controllers. We evaluate the QoT predictor training and auto-scaling capabilities in a real WDM/SDM testbed.

This demo shows a cloud-native SDN controller that can estimate end-to-end QoT using both analytical (GNPy) and machine learning algorithms on WDM systems. This transport SDN controller is able to scale horizontally using custom metrics.

We validate the deployment of isolated transport network slices in IP over DWDM network. To this end, an isolated transport network slice is deployed using multi-layer isolation mechanisms based on OpenConfig and ONF Transport API.

This demo showcases an SDN control platform configuring VCSEL-based photonic transceiver and white-box nodes for end-to-end programmability in disaggregated optical metro networks also including the spatial dimension with a polymer switch and 25km 19-core MCF.

This paper presents and experimentally validates a Blockchain-based architecture to manage End-to-End Network Slice Deployment by stitching Network Slice Subnets in edge/cloud computing domains connected through packet/optical transport networks do- mains managed by different operators.

We provide an overview of SDN control architectures for WDM over SDM (WDMoSDM) optical networks. We address dynamic management of end-to-end connec- tivity services and WDM virtual network topologies (VNTs) for partially disaggregated multi-domain WDMoSDM networks.