WOS4 – Wireless, Optical and Satellite Networks
Thursday, 4 June 2026, 16:30-18:00, room Sala 5 (1st floor)
Session Chair: tbd
ISAC Design for Intelligent Handover in LEO Satellites
Sovit Bhandari and Thang X. Vu (University of Luxembourg, Luxembourg); Nhan Nguyen (University of Oulu, Finland); Symeon Chatzinotas (University of Luxembourg, Luxembourg)
Fully exploiting the recent deployment of mega-constellations of low Earth orbit (LEO) satellites requires seamless handovers (HOs) between satellites to ensure uninterrupted broadband and direct-to-cell services. Conventional break-before-make HO protocols, although supported by inter-satellite links, suffer from beamforming delays due to the high orbital velocities of LEO satellites. To address these limitations, we propose an integrated sensing and communication (ISAC)-assisted HO (ISAC-HO) protocol that enables make-before-break HOs via ISAC-enabled ground terminals (GTs). A novel ISAC design capable of generating a three-dimensional (3D) beampattern under realistic conditions allows GTs to sense approaching LEO satellites without significantly compromising communication with the currently serving LEO satellite. The design problem is highly challenging due to its non-convexity and mixed-integer nature. To tackle these challenges, we propose an approach that leverages Riemannian manifold optimization and closed-form solutions. Numerical results validate that the proposed approach significantly improves the communications–sensing performance tradeoff compared to baseline designs, ensuring smooth HO.
Performance Analysis of 5G RAN Slicing Deployment Options in Industry 4.0 Factories
Oscar Adamuz-Hinojosa, Abdelhilah Abdeselam, Pablo Muñoz, Pablo Ameigeiras and Juan M. Lopez-Soler (University of Granada, Spain)
This paper studies Radio Access Network (RAN) slicing strategies for 5G Industry 4.0 networks with ultra-reliable low-latency communication (uRLLC) requirements. We comparatively analyze four RAN slicing deployment options that differ in slice sharing and per-line or per-flow isolation. Unlike prior works that focus on management architectures or resource allocation under a fixed slicing structure, this work addresses the design of RAN slicing deployment options in the presence of multiple production lines and heterogeneous industrial flows. An SNC-based analytical framework and a heuristic slice planner are used to evaluate these options in terms of per-flow delay guarantees and radio resource utilization. Results show that under resource scarcity only per-flow slicing prevents delay violations by tightly matching resources to per-flow delay targets, while slice-sharing and hybrid deployments improve aggregation efficiency at the cost of weaker protection for the most delay-critical flows. Execution-time results confirm that the planner operates at Non-RT time scales, enabling its integration within O-RAN Non-RT RIC loops.
Sleep Mode Management for Energy Savings in Realistic 6G Cell-Free Network Scenarios
Remco Litjens (TNO, The Netherlands); Daan Den Ouden (Delft University of Technology, The Netherlands); Maria Raftopoulou (TNO, The Netherlands); Haibin Zhang (TNO, The Netherlands & Eindhoven University of Technology, The Netherlands)
We propose a novel sleep mode management algorithm for access points in 6G cell-free networks that is able to respond to both large- and small-timescale traffic load fluctuations and aims to minimise energy consumption under coverage and throughput performance constraints. The simulation-based algorithm assessment and optimisation of its configuration is conducted for realistic scenarios, characterised by a non-negligible transition time for access points to enter/exit a deep sleep mode, a network deployment using available lampposts in downtown Amsterdam and a spatial user distribution based on demographic data for the same area. The results indicate that energy savings of 17.11% can be achieved if a single load-agnostic algorithm configuration is to be chosen, or 21.54% for load-optimised configurations, both relative to a baseline scenario without a deep sleep mode. To illustrate the importance of considering a realistic transition time into/out of deep sleep, these energy savings are found to be as high as 31.23% and 33.46%, respectively, if we had unrealistically assumed transitions into/out of deep sleep to be instantaneous, as considered elsewhere.
Synchronous Multi-User Distributed MIMO of 57.6 MBd 4096-QAM over a 1-Bit Sigma-Delta Radio-over-Fiber Fronthaul
Achim Vandierendonck (Universiteit Gent, Belgium); Muteen Munawar (Ghent University & IMEC, Belgium); Fatemeh Zardosht (Ghent University, Belgium); Caro Meysmans (Ghent University-IMEC, Belgium); Ingrid Moerman (Ghent University – IMEC, Belgium); Mamoun Guenach (Imec, Leuven & Alcatel Lucent, Belgium); Guy Torfs (Ghent University & Imec, Belgium)
Distributed multiple-input multiple-output (MIMO) systems promise enhanced coverage and capacity for future dense wireless deployments, but require tight synchronization between geographically separated access points to enable coherent joint transmission. Sigma-delta modulated signals over fiber combines the synchronization benefit from analog radio-over-fiber and the low cost of digital radio-over-fiber. This paper demonstrates wireless synchronous distributed MIMO transmission of 4096-QAM, 1024-QAM, and 256-QAM for a single user, two co-located users, and four co-located users. The testbed uses a carrier frequency of 3.686 GHz and is set-up in a configuration allowing up to four user equipments (UEs) with one antenna each to transmit to distributed access points (APs) with eight antennas in total. With the tight synchronization accuracy provided by the 1-bit sigma-delta radio-over-fiber fronthaul synchronization across remote radio units, and optimal signal processing, 1.8 Gbps aggregated transmission to four co-located users is achieved with no errors.
Full-Duplex Real-Time Terahertz Communication System with Quasi-Optical Beam Steering Capabilities
Simon Haussmann, Benjamin Schoch and Lukas Gebert (University of Stuttgart, Germany); Axel Tessmann (Fraunhofer IAF, Germany); Aleksey Dyskin (NVIDIA, Israel); Elad Mentovich (NVIDIA Corporation, Israel); Ingmar Kallfass (University of Stuttgart, Germany)
In this paper we present a full-duplex real-time Terahertz communication system for indoor applications. Employing superheterodyne transmit and receive front-ends, operating in the frequency range of 275 – 325 GHz, in combination with mmW-modems a wireless point-to-multipoint connection with Gigabit data rate between multiple terminals is established. Using quasi-optical beam-steering with a galvanometer, the connection between two network nodes and a common node is switched dynamically. The terminals are located at a distance of approximately 8 m from the common node. Using standard network components in conjunction with custom-build 300-GHz transmit-receive front-ends this work extends the current state of the art in Terahertz communication by the wireless transmission of 9.76 Gbit/s of TCP-based internet traffic that is transmitted wirelessly at 300 GHz in full-duplex between the three terminals.
