George Lyberopoulos

Our primary focus in this study is on the potential benefits to military communications from integrating Non-Terrestrial Networks (NTN) into the existing 5G terrestrial network architecture. Despite current 3rd Generation Partnership Project (3GPP) standardization efforts, considerable impediments exist to the full adoption and adaptation of 5G Low Earth Orbit (LEO) satellite integration to satisfy the special demands and requirements of military communication. Military communications, unlike civilian networks, require architecture that can withstand complex and changing environments. This paper provides a complete review of the requirements for military communications. The requirements are based on actual military application scenarios, as well as standards developed by organizations such as the North Atlantic Treaty Organization (NATO), the United States (U.S.) Department of Defense (DoD), the European Defense Agency (EDA) and the China Central Military Commission (CMC). Furthermore, in this work, we propose a novel 5G-LEO NTN backhaul architecture that utilizes multi-link LEO aggregation and Virtual Private Network (VPN) tunneling. The proposed architecture is evaluated in a defense-oriented scenario, focusing on security, resilience and high-throughput communication.

The 6G-EWOC project seeks to create an AI-enhanced fiber-wireless optical 6G network to support advanced use cases for Fully Autonomous Vehicles (FAVs) by establishing a new access network incorporating the integration of both fixed/wireless optical and wireless/RF technologies. The access network will be supported by a fast, reconfigurable, highly dynamic and customizable optical fiber-based fronthaul infrastructure which will minimize optoelectronic transitions through tunable and programmable devices, as well as low energy photonic switching of (packet/optical) spectrum and spatial resources, managed by AI-enabled SDN. End-to-end connectivity between AI-based edge computation units will enable advanced Connected and Automated Mobility (CAM) services over a rapid, adaptable network architecture.

We present a real-world Gigabit Passive Optical Network (GPON)-based Fiber to the Home (FTTH) network serving up to 32 users, installed in COSMOTE laboratories in Athens. The deployment relies on the use of fiber optics and GPON telecom equipment which are identical to those found in the currently deployed FTTH infrastructure. We describe real-life network designs that correspond to specific installations considered in Athens urban metropolitan area. We propose a practical upstream Quantum Access Network (QAN) over the installed FTTH network, relied on a centralized quantum receiver (Bob) station located at the operator's Central Office, which exploits the Time-Division Multiplexing (TDM) framing technique to receive single-photons from multiple independent quantum transmitters (Alice) located at users premises. This integration scheme is characterized by performing a series of noise measurements at single-photon level to evaluate the potential of the coexistence of classical/quantum links on the same fiber cores. The noise count rates are found to follow the Raman noise profile for specified values of effective Raman cross-sections of downstream and upstream GPON data channels. Subsequently, the experimental results are exploited to evaluate the performance of the widely-used Coherent One Way (COW) Quantum Key Distribution (QKD) protocol. The presented simulation results for the quantum layer suggest the feasibility of our integration scheme for short feeder fiber segments. Finally, the dependance of the Secure Key Rate (SKR) on the network capacity is also discussed.

The proliferation of smart mobile devices and data hungry mobile applications are driving the demand for faster mobile networks. Long Term Evolution (LTE), the 4th Generation of mobile network technology standardized by the 3rd Generation Partnership Project (3GPP) [1], aims at satisfying this demand by offering faster connection speeds at both the downlink and the uplink, increased network capacity and better coverage. The rapid penetration of LTE in different countries creates a vast field for innovation in terms of mobile broadband services. At the same time, research for the next generation mobile networks has already begun with the examination and evaluation of candidate technologies and architectures. Given the practical requirement for backward compatibility between successive technologies, it is rational to assume that these technologies, often referred to as Beyond 4th and towards the 5th Generation (B4G and 5G), will naturally evolve from the extension of LTE with new advanced features.

In future mobile networks, the evolution of optical transport architectures enabling the flexible, scalable interconnection of Baseband Units (BBUs) and Radio Units (RUs) with heterogeneous interfaces is a significant issue. In this paper, we propose a multi-technology hybrid transport architecture that comprises both analog and digital-Radio over Fiber (RoF) mobile network segments relying on a dynamically reconfigurable optical switching node. As a step forward, the integration of the discussed network layout into an existing mobile infrastructure is demonstrated, enabling the support of real-world services through both standard digital and Analog–Intermediate- Frequency over Fiber (A-IFoF)-based converged fiber–wireless paths. Emphasis has been placed on the implementation of a real-time A-IFoF transceiver that is employed through a single embedded fully programmable gateway array (FPGA)-based platform that serves as an Ethernet to Intermediate Frequency (IF) bridge for the transmission of legacy traffic over the analog network segment. The experimental evaluation of the proposed concept was based on the dynamic optical routing of the legacy Common Public Radio Interface (CPRI), 1.5 GBaud analog-intermediate frequency-over-fiber (A-IFoF)/mmWave and 10 Gbps binary optical waveforms, showing acceptable error vector magnitude (EVM) values for the complex radio waveforms and error-free operation for binary optical streams, with Bit Error Rate (BER) values less than 10⁻⁹. Finally, the end-to-end proof-of-concept demonstration of the proposed solution was achieved through the delivery of 4K video streaming and Internet Protocol (IP) calls over a mobile core network.

This article presents a converged 5G network infrastructure and an overarching architecture to jointly support operational network and end-user services, proposed by the EU 5G PPP project 5G-XHaul. The 5G-XHaul infrastructure adopts a common fronthaul/backhaul network solution, deploying a wealth of wireless technologies and a hybrid active/passive optical transport, supporting flexible fronthaul split options. This infrastructure is evaluated through a novel modeling. Numerical results indicate significant energy savings at the expense of increased end-user service delay.

The growing popularity of smart mobile devices such as smartphones and tablets has made them an attractive target for cyber-criminals, resulting in a rapidly growing and evolving mobile threat as attackers experiment with new business models by targeting mobile users. With the emergence of the first large-scale mobile botnets, the core network has also become vulnerable to distributed denial-of-service attacks such as the signaling attack. Furthermore, complementary access methods such as Wi-Fi and femtocells introduce additional vulnerabilities for the mobile users as well as the core network. In this paper, we present the NEMESYS approach to smart mobile network security. The goal of the NEMESYS project is to develop novel security technologies for seamless service provisioning in the smart mobile ecosystem, and to improve mobile network security through a better understanding of the threat landscape. To this purpose, NEMESYS will collect and analyze information about the nature of cyber-attacks targeting smart mobile devices and the core network so that appropriate counter-measures can be taken. We are developing a data collection infrastructure that incorporates virtualized mobile honeypots and honeyclients in order to gather, detect and provide early warning of mobile attacks and understand the modus operandi of cyber-criminals that target mobile devices. By correlating the extracted information with known attack patterns from wireline networks, we plan to reveal and identify the possible shift in the way that cyber-criminals launch attacks against smart mobile devices.