6ET (Session2) & OPE – 6G Technologies II
Wednesday, 8 June 2022, 16:00-17:30, RoomC238
Session Chair: Antonio Clemente (CEA-LETI Minatec, FR)
Network Intelligence for Virtualized RAN Orchestration: The DAEMON Approach
Marco Gramaglia (Universidad Carlos III de Madrid, Spain); Miguel Camelo (University of Antwerp – imec, Belgium); Lidia Fuentes and Joaquín Ballesteros (University of Malaga, Spain); Luca Cominardi and Gabriele Baldoni (ADLINK Technology, France); Andres Garcia-Saavedra (NEC Labs Europe, Germany); Marco Fiore (IMDEA Networks Institute, Spain)
Next-generation mobile networks will largely benefit from advances in softwarization and cloudification of network functions. However, fully exploiting the new potential of flexible network architectures in front of increasingly demanding service volumes and requirements calls for an extremely effective integration of Network Intelligence (NI) solutions into production infrastructures. While current standardization efforts towards embedding NI in beyond-5G and 6G systems are still in their infancy, the DAEMON project is developing technologies for a NI-native generation of mobile networks. In this paper, we present current evolutions proposed by DAEMON in terms of a general model for the representation of NI instances, which facilitates their synergic integration in network environments. We showcase the practical viability and advantages of the proposed approach with two state-of-the-art NI algorithms for vRAN orchestration implemented into an open-source data flow programming framework.
Multi-User Wireless Communications with Holographic MIMO Surfaces: A Convenient Channel Model and Spectral Efficiency Analysis
Li Wei (Singapore University of Technology and Design, Singapore); Chongwen Huang (Zhejiang University, China); George C. Alexandropoulos (University of Athens, Greece); Wei E. I. Sha and Zhaoyang Zhang (Zhejiang University, China); Mérouane Debbah (Huawei, France); Chau Yuen (Singapore University of Technology and Design, Singapore)
The multi-user Holographic Multiple-Input and Multiple-Output Surface (MU-HMIMOS) paradigm, which is capable of realizing large continuous apertures with minimal power consumption and of shaping radio wave propagation at will, has been recently considered as an energy-efficient solution for future wireless networks. The tractable channel modeling of MU-HMIMOS signal propagation is one of the most critical
challenges, mainly due to the coupling effect induced by the excessively large number of closely spaced patch antennas. In this
paper, we focus on this challenge for downlink communications and model the electromagnetic channel in the wavenumber domain using the Fourier plane wave representation. Based on the proposed model, we devise a Zero-Forcing (ZF) precoding scheme, capitalizing on the sampled channel variance that depends on the number and spacing of the HMIMOS patch antennas, and perform a spectral efficiency analysis. Our simulation results showcase that the more patch antennas and the larger their spacing is, the performance of the considered MU-HMIMOS system improves. In addition, it is demonstrated that our theoretical performance expressions approximate sufficiently well the simulated spectral efficiency, even for the highly
correlated cases, thus verifying the effectiveness and robustness of the presented analytical framework.
On the Impacts of Phase Shifting Design and Eavesdropping Uncertainty on Secrecy Metrics of RIS-Aided Systems
Long Kong (University of Ottawa, Canada); Steven Kisseleff, Symeon Chatzinotas and Björn Ottersten (University of Luxembourg, Luxembourg); Melike Erol-Kantarci (University of Ottawa & Ericsson, Canada)
Considering the impacts of eavesdroppers’ location uncertainty and the phase adjustment uncertainty, namely imperfect coherent phase shifting and discrete phase shifting, on the reconfigurable intelligent surfaces (RIS)-assisted wireless communication system, this paper investigates the secrecy outage probability (SOP), the lower bound of SOP, and the probability of non-zero secrecy capacity (PNZ) of RIS-assisted systems from the information-theoretic perspective. More specifically, analytical and simulation results are presented to show that (i) the SOP gain due to the increase of the RIS reflecting elements number gradually decreases; and (ii) both phase shifting designs demonstrate the same PNZ secrecy performance, in other words, the random discrete phase shifting outperforms the imperfect coherent phase shifting design with reduced complexity.
A Novel RIS-Aided EMF Exposure Aware Approach Using an Angularly Equalized Virtual Propagation Channel
Nour Awarkeh (France); Dinh-Thuy Phan-Huy (Orange, France); Marco Di Renzo (CentraleSupelec-University, France)
Massive Multiple-Input Multiple-Output systems with beamforming are key components of the fifth and the future 6th generations of networks. Unfortunately, such systems can create unwanted regions of electromagnetic field exposure exceeding the regulatory threshold, even beyond the circle around the BS that limits the distance between people and the BS antenna. Recently, exposition aware beamforming schemes aided by self-tuning reconfigurable intelligent surfaces derived from maximum ratio transmission beamforming, have been proposed: reduced beamforming and truncated beamforming. However, reduced beamforming strongly degrades the received power at the target user and truncated beamforming is highly complex. In this paper, we propose a novel and low complexity reconfigurable intelligent surface aided beamforming scheme called Equalized beamforming, that applies maximum ratio transmission to an angularly equalized virtual propagation channel. Our simulations show that our proposed scheme outperforms the reduced beamforming scheme, whilst complying with the exposition regulation.
Techtile – Open 6G R&D Testbed for Communication, Positioning, Sensing, WPT and Federated Learning
Gilles Callebaut and Jarne Van Mulders (KU Leuven, Belgium); Geoffrey Ottoy (KU Leuven & Technology Campus Ghent, Belgium); Daan Delabie, Bert Cox and Nobby Stevens (KU Leuven, Belgium); Liesbet Van der Perre (KUL, Belgium)
New concepts for next-generation wireless systems are being developed. It is expected that these 6G and beyond systems will incorporate more than only communication, but also sensing, positioning, (deep) edge computing, and other services. The discussed measurement facility and approach, named Techtile, is an open, both in design and operation, and unique testbed to evaluate these newly envisioned systems. Techtile is a multi-functional and versatile testbed, providing fine-grained distributed resources for new communication, positioning and sensing technologies. The facility enables experimental research on hyper-connected interactive environments and validation of new algorithms and topologies. The backbone connects 140~resource units equipped with edge computing devices, software-defined radios, sensors, and LED sources. By doing so, different network topologies and local-versus-central computing can be assessed. The introduced diversity of i) the technologies (e.g., RF, acoustics and light), ii) the distributed resources and iii) the interconnectivity allows exploring more degrees and new types of diversity, which can be investigated in this testbed.