Ramon Casellas

Ramon Casellas
Centre Tecnològic de Telecomunicacions de Catalunya (CTTC/CERCA)

PhD

About

372
Publications
37,063
Reads
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3,958
Citations
Additional affiliations
March 2006 - present
CTTC Catalan Telecommunications Technology Centre
Position
  • Senior Researcher

Publications

Publications (372)
Conference Paper
Full-text available
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...
Preprint
The H2020 METRO-HAUL European project has architected a latency-aware, cost-effective, agile, and programmable optical metro network. This includes the design of semidisaggregated metro nodes with compute and storage capabilities, which interface effectively with both 5G access and multi-Tbit/s elastic optical networks in the core. In this paper, w...
Article
The H2020 METRO-HAUL European project has architected a latency-aware, cost-effective, agile, and programmable optical metro network. This includes the design of semi-disaggregated metro nodes with compute and storage capabilities, which interface effectively with both 5G access and multi-Tbit/s elastic optical networks in the core. In this paper,...
Article
This Special Issue contains a collection of outstanding papers covering several recent advances in optical networks for 5G communications and beyond. Papers are organized into four categories: network resource planning; optical access networks; optical fronthaul solutions; and autonomous and data-driven network management. In this introduction, a b...
Preprint
We report the automated deployment of 5G services across a latency-aware, semidisaggregated, and virtualized metro network. We summarize the key findings in a detailed analysis of end-to-end latency, service setup time, and soft-failure detection time.
Article
Full-text available
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...
Article
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...
Article
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...
Article
Full-text available
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...
Chapter
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...
Article
Network operators are facing a critical issue on their optical transport networks to deploy 5G+ and Internet of Things services. They need to address the capacity increase by a factor of 10, while keeping a similar cost per user. Over the past years, network operators have been working on the optical disaggregated approach with great interest for a...
Conference Paper
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.
Article
Full-text available
Network services in 5G will be rolled out as pools of virtual network functions (VNFs) exploiting the advantages of both software-defined networking and network function virtualization. In this context, 5G network services are envisaged as ordered sequences of VNFs resulting in the so-called VNF Forwarding Graphs (VNFFGs). Such VNFs can be allocate...
Article
This paper introduces a novel and simplified cost model for designing and evaluating a Central Office Rearchitected as a Datacenter (CORD). The model includes equipment and elements for the realization of optical, packet switching, and data center parts with a special focus not only on relative costs but also on power consumption figures. The cost...
Article
Full-text available
Transport network virtualization provides the necessary data and control plane technologies as key enablers of future networks. The interaction between network slicing and optical transport network virtualization architectures is under study to automate effective network resource orchestration. In this paper, we present an harmonized network slicin...
Article
The need of telecommunications operators to reduce Capital and Operational Expenditures in networks which traffic is continuously growing has made them search for new alternatives to simplify and automate their procedures. Because of the different transport network segments and multiple layers, the deployment of end-to-end services is a complex tas...
Article
Full-text available
In this paper, we focus on the design of different node architectures suitable for Few-Mode Multi-Core Fibers (FM-MCFs) based networks. Both dimensions, core and mode, open different possible ways to group spatial channels depending on the physical impairments of the Space-Division Multiplexed (SDM) optical fibers. Moreover, the channel switching a...
Technical Report
Full-text available
This document provides Path Computation Element Communication Protocol (PCEP) extensions for the support of Routing and Wavelength Assignment (RWA) in Wavelength Switched Optical Networks (WSONs). Path provisioning in WSONs requires an RWA process. From a path computation perspective, wavelength assignment is the process of determining which wavele...
Article
This work provides a techno-economic evaluation of optical disaggregation architectures in the context of metropolitan area networks. The study compares two optical disaggregation options (partial vs. total) against the legacy benchmark where optical equipment is subject to vendor lock-in, as it is deployed in most networks today. We show that emer...
Article
Full-text available
Metropolitan networks are undergoing a major technological breakthrough leveraging the capabilities of software-defined networking (SDN) and network function virtualization (NFV). NFV permits the deployment of virtualized network functions (VNFs) on commodity hardware appliances which can be combined with SDN flexibility and programmability of the...
Article
This paper reports a technical demonstration showing the use of the ONOS SDN controller for disaggregated transport networks, summarizing the latest developments and results within the Open Networking Foundation (ONF) Open Disaggregated Transport Networks (ODTN) project. The demonstration mainly covers the dynamic provisioning of data connectivity...
Chapter
In future 5G infrastructures, network services will be deployed through sets of Virtual Network Functions (VNFs) leveraging the advantages of both Software Defined Networking (SDN) and Network Function Virtualization (NFV). A network service is composed of an ordered sequence of VNFs, i.e., VNF Forwarding Graph (VNFFG), deployed across distributed...
Chapter
Most deployed optical transport networks are proprietary, behaving as a closed, highly coupled, single-vendor managed domain. Although their control planes and management systems may export high-level and open northbound interfaces (NBI), the internal details and interfaces are not disclosed to the network operator. However, driven by the requireme...
Chapter
During last years, novel protocols and data models are arising to control and monitor optical network equipment. These protocols enable network programmability and automation by fulfilling the vision introduced by Software Defined Networking (SDN).
Article
Network slicing has been a major selling point of 5G networks, where a slice is roughly defined as a self-contained logical network on top of a shared infrastructure tailored for a specific service or vertical industry, composed of heterogeneous resources (computing, storage, bandwidths) and typically involving specific application and/or networkin...
Article
Full-text available
Use of disaggregated equipment in optical transport networks is emerging as an attractive solution to bring flexibility and break vendor lock-in dependencies. The disaggregation process requires standard protocols and interfaces between the control plane and network equipment. NETCONF has been selected as the standard protocol, and multiple initiat...
Article
Software-defined networking (SDN) and disaggregation are key technologies to fulfill the requirements of 5G and beyond optical metro networks. Indeed, open networking solutions will reduce vendor lock-in, achieving increased flexibility and programmability of the network. SDN-enabled sliceable bandwidth/bitrate variable transceivers (S-BVTs) are pr...
Article
Network operators are evolving their Optical Transport Networks in order to make them cost effective. In some scenarios, this means considering adopting Software Defined Networking principles along with open and standard interfaces, leveraging the underlying hardware programmability while, at the same time, considering the benefits of (partial) dis...
Article
Space division multiplexing (SDM) super-channels are the only way to guarantee a sustainable scaling of the optical line interface rate. High-capacity terabit interfaces can be deployed by logically associating several optical sub-channels transmitted in parallel in different spatial cores or modes in order to create an (logical) optical channel wi...
Conference Paper
We present the first SDN-enabled multi-domain multi-layer (WDM/SDM) control architecture for partially disaggregated optical networks with multiple WDM and SDM OLS domains and transponders to provision end-to-end TAPI connectivity services involving spatial and optical channels.
Conference Paper
We demonstrate a novel agent for optical disaggregated optical networks. When the Monitoring and Data Analytics detects a degradation, it recommends the SDN controller to trigger a network reconfiguration computed by a novel planning tool.