Ramon CASELLAS

Dr. Ramon CASELLAS

Centre Tecnologic De Telecomunicacions De Catalunya, Barcelona, Catalonia, Spain
orcid

Research Focus & Metrics

Academic Career Length

19Years (2008-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
31 January 2018 in Journal of Lightwave Technology
Verified
Journal Article
Open access
RMRaul Munoz
Raul Munoz
Ricard VilaltaRicard Vilalta
Ricard Vilalta
NYNoboru Yoshikane
Noboru Yoshikane
RCRamon CASELLAS
Ramon CASELLAS
RMRicardo Martinez
Ricardo Martinez
IMItsuro Morita
Itsuro Morita
IoT requires cloud infrastructures for data analysis (e.g., temperature monitoring, energy consumption measurement, etc.). Traditionally, cloud services have been implemented in large datacentres in the core network. Core cloud offers high-computational capacity with moderate response time, meeting the requirements of centralized services with low-delay demands. However, collecting information and bringing it into one core cloud infrastructure is not a long-term scalable solution, particularly as the volume of IoT devices and data is forecasted to explode. A scalable and efficient solution, both at the network and cloud level, is to distribute the IoT analytics between the core cloud and the edge of the network (e.g. first analytics on the edge cloud and the big data analytics on the core cloud). For an efficient distribution of IoT analytics and use of network resources, it requires to integrate the control of the transport networks (packet and optical) with the distributed edge and cloud resources in order to deploy dynamic and efficient IoT services. This paper presents and experimentally validates the first IoT-aware multi-layer (packet/optical) transport SDN and edge/cloud orchestration architecture that deploys an IoT-traffic control and congestion avoidance mechanism for dynamic distribution of IoT processing to the edge of the network (i.e., edge computing) based on the actual network resource state.

17 July 2024 in Journal of Optics
Verified
Journal Article
Open access
PDF file
EAErik Agrell
Erik Agrell
MKMagnus Karlsson
Magnus Karlsson
FPFrancesco Poletti
Francesco Poletti
SNShu Namiki
Shu Namiki
XCXi (Vivian) Chen
Xi (Vivian) Chen
MUMurat Uysal
Murat Uysal
The Covid-19 pandemic showed forcefully the fundamental importance broadband data communication and the internet has in our society. Optical communications forms the undisputable backbone of this critical infrastructure, and it is supported by an interdisciplinary research community striving to improve and develop it further. Since the first ‘Roadmap of optical communications’ was published in 2016, the field has seen significant progress in all areas, and time is ripe for an update of the research status. The optical communications area has become increasingly diverse, covering research in fundamental physics and materials science, high-speed electronics and photonics, signal processing and coding, and communication systems and networks. This roadmap describes state-of-the-art and future outlooks in the optical communications field. The article is divided into 20 sections on selected areas, each written by a leading expert in that area. The sections are thematically grouped into four parts with 4–6 sections each, covering, respectively, hardware, algorithms, networks and systems. Each section describes the current status, the future challenges, and development needed to meet said challenges in their area. As a whole, this roadmap provides a comprehensive and unprecedented overview of the contemporary optical communications research, and should be essential reading for researchers at any level active in this field.

15 January 2018 in Journal of Lightwave Technology
Verified
Journal Article
Open access
RCRamon CASELLAS
Ramon CASELLAS
RMRicardo Martinez
Ricardo Martinez
Ricard VilaltaRicard Vilalta
Ricard Vilalta
RMRaul Munoz
Raul Munoz
Automating the provisioning of telecommunications services, deployed over a heterogeneous infrastructure (in terms of domains, technologies and management platforms), remains a complex task, yet driven by the constant need to reduce costs and service deployment time. This is more so, when such services are increasingly conceived around inter-connected functions and require allocation of computing, storage and networking resources. This automation drives the development of service and resource orchestration platforms that extend, integrate and build on top of existing approaches, macroscopically adopting Software Defined Networking principles, leveraging programmability and open control in view of inter-operability. Such systems are combining centralized and distributed elements, integrating platforms whose development may happen independently and parallel, and are constantly adapting to ever changing requirements, such as virtualization and slicing. Of specific interest is the (optical) transport network segment, traditionally operated independently via closed proprietary systems, and characterized by being relatively complex and hard to reach consensus regarding modelling and abstraction. In view of the targets, the transport network segment needs to be integrated into such service orchestration platforms efficiently. In this context, this paper aims at providing an introduction to control, management and orchestration systems, of which the network control is a core component, along their main drivers, key benefits and functional/protocol architectures. It covers multi-domain and multi-layer networks and includes complex use cases, challenges and current trends such as joint IT/network orchestration and 5G network slicing

23 August 2013 in Journal of Optical Communications and Networking
Verified
Journal Article
Closed access
PDF file
RCRamon CASELLAS
Ramon CASELLAS
RMRicardo Martínez
Ricardo Martínez
RMRaül Muñoz
Raül Muñoz
Ricard VilaltaRicard Vilalta
Ricard Vilalta
LLLei Liu
Lei Liu
IMItsuro Morita
Itsuro Morita
Optics InfoBase is the Optical Society's online library for flagship journals, partnered and copublished journals, and recent proceedings from OSA conferences.

4 March 2010 in Journal of Lightwave Technology
Verified
Journal Article
Closed access
RMRicardo Martinez
Ricardo Martinez
RCRamon CASELLAS
Ramon CASELLAS
RMR. Muoz
R. Muoz
TTTakehiro Tsuritani
Takehiro Tsuritani
In the evolution from opaque networks, using 3R regenerators and OEO conversions for every wavelength channel, towards transparent networks, relying on end-to-end all-optical connections, translucent networks is considered as an intermediate step. A translucent network is a cost-efficient infrastructure between opaque and transparent networks, that aims at attaining an adequate trade-off between network construction cost (i.e., due to the high cost of 3R regenerators) and the service provisioning performance (i.e., end-to-end optical signal quality). This article addresses the dynamic provisioning of connections within a GMPLS-enabled translucent wavelength switched optical network with sparse 3R regenerators. To this end, translucent-oriented GMPLS protocol extensions are proposed to, on the one hand, disseminate required per node regenerator availability and OSNR-related link and node attributes and, on the other hand, allocate regenerator resources when setting up connections. An on-line OSNR-based impairment-aware RWA algorithm is devised to compute routes aiming at satisfying two constraints: the wavelength continuity constraint and the end-to-end optical signal quality. If either constraint cannot be satisfied, available regenerators along the route are used. To the best of our knowledge, the novelty and progress of this work is that, for the first time, both the proposed translucent GMPLS protocol enhancements and the performance of the RWA algorithm are combined within an experimental control plane network scenario (CTTC's ADRENALINE testbed). This allows validating and evaluating the feasibility of the described translucent GMPLS routing strategy when being potentially deployed into real WSON networks. Several configurations with numbers of 3R regenerators and wavelength channels per link, are experimentally evaluated and compared mainly in terms of the connection blocking probability. Although concrete details about the measured average setup delay are also discussed.

16 January 2015 in Journal of Lightwave Technology
Verified
Journal Article
Open access
RMRaul Munoz
Raul Munoz
DSDimitra Simeonidou
Dimitra Simeonidou
NYNoboru Yoshikane
Noboru Yoshikane
TTTakehiro Tsuritani
Takehiro Tsuritani
VLVictor Lopez
Victor Lopez
RNReza Nejabati
Reza Nejabati
A multidomain optical transport network composed of heterogeneous optical transport technologies (e.g., flexi/fixed-grid optical circuit switching and optical packet switching) and control plane technologies (e.g., centralized OpenFlow or distributed GMPLS) does not naturally interoperate, and a network orchestration mechanism is required. A network orchestrator allows the composition of end-to-end network service provisioning across multidomain optical networks comprising different transport and control plane technologies. Software-defined networking (SDN) is a key technology to address this requirement, since the separation of control and data planes makes the SDN a suitable candidate for end-to-end provisioning service orchestration across multiple domains with heterogeneous control and transport technologies. This paper presents two different network orchestration's architectures based on the application-based network operations (ABNO) which is being defined by IETF based on standard building blocks. Then, we experimentally assesses in the international testbed of the STRAUSS project, an ABNO-based network orchestrator for end-to-end multi-layer (OPS and Flexi-grid OCS) and multidomain provisioning across heterogeneous control domains (SDN/OpenFlow and GMPLS/Stateful PCE) employing dynamic domain abstraction based on virtual node aggregation.