i2CAT Internet and Digital Innovation in Catalonia

Reconfigurable intelligent surfaces (RISs) are expected to play a crucial role in reaching the key performance indicators (KPIs) for future 6G networks. Their competitive edge over conventional technologies lies in their ability to control the wireless environment propagation properties at will, thus revolutionizing the traditional communication paradigm that perceives the communication channel as an uncontrollable black box. As RISs transition from research to market, practical deployment issues arise. Major roadblocks for commercially viable RISs are i) the need for a fast and complex control channel to adapt to the ever-changing wireless channel conditions, and ii) an extensive grid to supply power to each deployed RIS. In this paper, we question the established RIS practices and propose a novel RIS design combining self-configuration and energy self-sufficiency capabilities. We analyze the feasibility of devising fully-autonomous RISs that can be easily and seamlessly installed throughout the environment, following the new internet-of-surfaces (IoS) paradigm, requiring modifications neither to the deployed mobile network nor to the power distribution system. In particular, we introduce ARES, an Autonomous RIS with Energy harvesting and Self-configuration solution. ARES achieves outstanding communication performance while demonstrating the feasibility of energy harvesting (EH) for RISs power supply in future deployments.

Multimedia content represents a significant portion of the traffic in computer networks, and COVID-19 has only made this portion bigger, as it now represents an even more significant part of the traffic. This overhead can, however, be reduced when many users access the same content. In this context, Wi-Fi, which is the most popular Radio Access Technology, introduced the Group Addressed Transmission Service (GATS) with the amendment IEEE 802.11aa. GATS defines a set of policies aiming to make multicast traffic more robust and efficient. However, Wi-Fi is constantly evolving, and as it improves and greater bandwidths and data rates become available, it is necessary to reevaluate the behavior of mechanisms introduced in past amendments. This is also the case with GATS, whose policies have different behaviors and adapt better to different channel conditions. These policies have been evaluated in the past on High Throughput networks. Still, none of the evaluations provided insights into the behavior of GATS policies in Very-High Throughput (VHT) physical layers in a realistic manner. This is extremely relevant as a greater available bandwidth can impact the decisions of the GATS policy configuration. Thus, in this work, we present an evaluation of the IEEE 802.11aa amendment with a VHT physical layer in a realistic scenario that uses Minstrel as a rate adaptation algorithm simulated in NS-3.

This paper addresses the challenges posed by new 5G-IoT (Internet-of-Things) satellite constellations in telecommunication. The focus is on the development of an efficient and autonomous management system for such constellations. The authors previously presented a management tool and a simulator capable of computing visibility events across multiple locations, including ground stations, user equipment, and target areas. Here, the contact simulator has been upgraded to incorporate key features such as inter-satellite links, Kalman filter for orbit determination, and the implementation of link budgets. These advancements enable improved management and optimization of IoT satellite constellations in the evolving telecommunication landscape. The structure of the tool is restated with minor advancements in automation and efficiency. I Introduction Since the beginning of the space era post-World War 2, low-Earth orbit (LEO) has been at the frontier of exploration in the hands of government agencies (e.g. NASA, ESA, JAXA, etc). However, in the past three decades, the cost and risk of launching spacecraft (s/c) have decreased, and huge interest in LEO has emerged from privately-owned corporations; interest in the form of telecommunications. 1 This influx is correlated to the numerous advancements in technology seen since the beginning of the 21 st century, many of which have come from the space sector itself. More recently, the current Internet network has gained popularity amongst researchers due to its relatively stagnant growth. Ground networks have not caught up to the rapid development of advanced technologies. 2 The rise of 5 th generation networks (5G) and the Internet of Things (IoT) has been, for lack of a better word, revolutionary, and has left the preexisting foundations of telecommunications behind, leaving companies in search of solutions. 3 Solutions that come in the form of Non-Terrestrial Networks (NTN). 2, 4 Non-Terrestrial Networks integrate with current terrestrial systems to promote global connectivity with a three-dimensional architecture. A typical structure of an NTN is represented in Figure 1. Here, three primary

We consider a reconfigurable intelligent surface (RIS) assisted multiple-input multiple-output (MIMO) system in the presence of scattering objects. The MIMO transmitter and receiver, the RIS, and the scattering objects are modeled as mutually coupled thin wires connected to load impedances. We introduce a novel numerical algorithm for optimizing the tunable loads connected to the RIS, which does not utilize the Neumann series approximation. The algorithm is provably convergent, has polynomial complexity with the number of RIS elements, and outperforms the most relevant benchmark algorithms while requiring fewer iterations and converging in a shorter time.

COVID-19 has changed the way we use networks, as multimedia content now represents an even more significant portion of the traffic due to the rise in remote education and telecommuting. In this context, in which Wi-Fi is the predominant radio access technology (RAT), multicast transmissions have become a way to reduce overhead in the network when many users access the same content. However, Wi-Fi lacks a versatile multicast transmission method for ensuring efficiency, scalability, and reliability. Although the IEEE 802.11aa amendment defines different multicast operation modes, these perform well only in particular situations and do not adapt to different channel conditions. Moreover, methods for dynamically adapting them to the situation do not exist. In view of these shortcomings, artificial intelligence (AI) and machine learning (ML) have emerged as solutions to automating network management. However, the most accurate models usually operate as black boxes, triggering mistrust among human experts. Accordingly, research efforts have moved towards using Interpretable-AI models that humans can easily track. Thus, this work presents an Interpretable-AI solution designed to dynamically select the best multicast operation mode to improve the scalability and efficiency of this kind of transmission. The evaluation shows that our approach outperforms the standard by up to 38%.

PALANTIR, an EU-funded Innovation Action project, delivers tailored and pervasive resource protection through the Security-as-a-Service paradigm. This demo presents the architecture and validates the prototype against three threat scenarios with botnet, data breach and tampering attacks.

In this paper, we investigate three forms of virtual reality (VR) content production and consumption. Namely, pre-rendered 360 stereoscopic video, full real-time rendered 3D scenes, and the combination of a real-time rendered 3D environment with a pre-rendered video billboard used to present the central elements of the scene. We discuss the advantages and disadvantages of these content formats and describe the production of a piece of VR cinematic content for the three formats. The cinematic segment presented the interaction between two actors, which the VR user could watch from the virtual room next-door, separated from the action by a one-way mirror. To compare the three content formats, we carried out an experiment with 24 participants. In the experiment, we evaluated the quality of experience, including presence, simulation sickness and the participants’ assessment of content quality, for each of the three versions of the cinematic segment. We found that, in the context of our cinematic segment, combining video and 3D content produced the best experience. We discuss our results, including their limitations and the potential applications.

The future of the manufacturing industry highly depends on digital systems that transform existing production and monitoring systems into autonomous systems fulfilling stringent requirements in terms of availability, reliability, security, low latency, and positioning with high accuracy. In order to meet such requirements, private 5G networks are considered a key enabling technology. In this paper, we introduce the 5G-CLARITY system that integrates 5GNR, Wi-Fi and LiFi access networks, and develops novel management enablers to operate B5G private networks. We describe three core features of 5G-CLARITY including a multi-connectivity framework, a high precision positioning server and a management system to orchestrate private network slices. These features are evaluated by means of packet-level simulations and an experimental testbed demonstrating the ability of 5G-CLARITY to police access network traffic, to achieve cm-level positioning accuracy, and to provision private network slices in less than one minute.

With the expansion of 5G networks, new business models are arising where multi-tenancy and active infrastructure sharing will be key enablers for them. With these new opportunities, new security risks are appearing in the form of a complex and evolving threat landscape for 5G networks, being one of the main challenges for the 5G mass rollout. In 5G-enabled scenarios, adversaries can exploit vulnerabilities associated with resource sharing to perform lateral movements targeting other tenant resources, as well as to disturb the 5G services offered or even the infrastructure resources. Moreover, existing security and trust models are not adequate to react to the dynamicity of the 5G infrastructure threats nor to the multi-tenancy security risks. Hence, we propose in this work a new security and trust framework for 5G multi-domain scenarios. To motivate its application, we detail a threat model covering multi-tenant scenarios in an underlying 5G network infrastructure. We also propose different ways to mitigate these threats by increasing the security and trust levels using network security monitoring, threat investigation, and end-to-end trust establishments. The framework is applied in a realistic use case of the H2020 5GZORRO project, which envisions a multi-tenant environment where domain owners share resources at will. The proposed framework forms a secure environment with zero-touch automation capabilities, minimizing human intervention.

Social Virtual Reality (VR) allows multiple distributed users getting together in shared virtual environments to socially interact and collaborate. This article explores the applicability and potential of Social VR in the broadcast sector, focusing on a live TV show use case, by providing three main contributions: 1) a novel and lightweight social VR platform; 2) a professional piece of VR content to recreate an interactive live TV show; and 3) an analysis of the performance and user experience. The Social VR platform includes different innovative and outstanding features compared to state-of-the-art solutions. It allows a real-time integration of remote users in shared virtual environments, using realistic volumetric representations and affordable capturing systems, thus not relying on the use of synthetic avatars. It supports a seamless and rich integration of heterogeneous media formats, including 3D scenarios, dynamic volumetric representation of users and (live/stored) stereoscopic 2D and 180°/360° videos. In addition, it enables low-latency interaction between volumetric users and a video-based presenter (Chroma keying) and a dynamic control of the media playout to adapt to the session's evolution. The article also describes the production process of an immersive an interactive TV show to demonstrate the platform's capabilities and its potential benefits. On the one hand, the results from objective tests show the satisfactory performance of the platform. On the other hand, the promising results from user tests support the potential impact of the presented platform, opening up new opportunities in the broadcast sector.

In a world with increasing traffic demands, wireless technologies aim to meet them by means of new Radio Access Technologies that provide faster connectivity. Such is the case of 4G and 5G. However, in indoor scenarios, where the capabilities of these technologies are significantly affected by the distance to the base station and the materials used in the construction of buildings, Wi-Fi is still the technology of reference thanks to its low cost and easy deployment. In this context, it is usual to find multi-AP Wi-Fi networks whose deployment has been carefully planned. However, the user-AP association decision procedure is not defined by the IEEE 802.11 standard. As a result, vendors choose selfish approaches based on signal strength. This leads to uneven user distributions and nonoptimal resource utilization. To deal with this, densification has been used over the years, but this is expensive as it needs more infrastructure. Moreover, this results in more APs in the same collision domain. To avoid the need for densification, in this paper we introduce WiMCA, a joint SDN-based user association and channel assignment solution for Wi-Fi networks that considers signal strength, channel occupancy and AP load to make better association decisions. Experimental results have demonstrated that, in terms of aggregated goodput, WiMCA outperforms approaches based on signal strength by 55%, providing better user level fairness and accommodating more users and traffic before reaching the point at which densification is needed.