1,720,971 research outputs found
Maximizing Airtime Efficiency for Reliable Broadcast Streams in WMNs with Multi-Armed Bandits
No full textWireless broadcast routing is a complex problem, shown in the literature to be NP-complete. Current protocols implement either heuristics to find solutions that are not guaranteed to be optimal or classic flooding. However, many future use cases, like automotive applications, industrial robotics, and multimedia broadcast, will require efficient yet reliable methods. In this work, we use contextual multi-armed bandits together with opportunistic routing (OR) and network coding (NC) to find approximately optimal solutions to the problem of broadcast routing in a distributed fashion. Each router independently learns its own transmission credit, i.e., the number of packets to forward for each innovative packet received, so that the airtime cost, subject to latency constraints, is minimized. Results show that the proposed solutions, particularly the deep learning based one, vastly improve the overall reliability, while performing close to MORE multicast in terms of airtime and to B.A.T.M.A.N. in latency, both being the best candidates in the respective discipline among the tested ones
5G NR Support for UAV-Assisted Cellular Communication on Non-Terrestrial Network
Full text linkThe use of Unmanned Aerial Vehicles (UAVs) to provide cellular communication in rural areas, disaster-hit regions, or during temporary events is gaining increasing attention due to its flexible deployment and energy efficiency compared to fixed terrestrial infrastructures. However, UAVs experience significant challenges such as the limited wireless connectivity provided by Ka-band frequency, and their flying time is constrained by the energy consumed during the data transmission and the complexity of the Baseband Unit (BBU) implementation. Using different lower layer functional split options (e.g., 7-1, 7-2, 7-2x, and 7-3), this paper provides a theoretical and simulation analysis of the 5G New Radio (NR) physical layer specifications to achieve a fronthaul bandwidth that can be supported by the Ka-band. These functional split options are then compared in terms of fronthaul bandwidth, theoretical throughput, connection density, number of functions deployed at the UAV, and the energy consumption of the fronthaul transmission to determine which functional split option is better suited for a multi-layered Non-Terrestrial Network (NTN)
Strategic Interaction Over Pump Power for Fidelity in Spontaneous Parametric Down-Conversion
No full textWe consider a scenario of spontaneous parametric down-conversion to generate entangled states that are used for quantum communications. Such a mechanism is vulnerable to attacks caused by an adversary that may inject power to the nonlinear crystal to drive the operating point away from maximum fidelity. We devise a low-cost strategic mechanism to counteract this attack, which corresponds to lowering the injected power anticipating the attack. If the attacker is also rational, this leads to a strategic interaction that can be studied with game theory. We show how the strategic response of the transmitter can mitigate the extent of the attack when it is not too strong
Assessing the Impact of Entanglement on Strategic Choices in Quantum Communication Networks
No full textWe investigate a scenario where two transmitters, Alice and Bob, send information to a passive receiver, Charlie through a quantum channel. We use a method based on quantum entanglement and apply game theory. In this setup, Alice and Bob each have a chance of successfully sending their messages and being entanglement with probability p and q, respectively, and there is a cost c involved. Our main focus is on using entanglement to assess the Price of Anarchy (PoA), which measures the degradation induced by selfish behavior when multiple players are involved. The most important result of our analysis is that the Price of Anarchy becomes very high when there are multiple Nash equilibria. This means that these systems require a careful management to avoid bad outcomes. Thus, we propose an implementable schematic (a network architecture based on entangled photons) to demonstrate how the game can be utilized in a real 5G network
Strategic Interaction Over Age of Information on a Quantum Wiretap Channel
No full textWe investigate a scenario where a transmitter (Alice) sends information to a legitimate receiver (Bob) through a quantum channel in the presence of an eavesdropper (Eve). The information leaked to Eve is made unavailable to Bob, which causes the system to behave like a partially degraded wiretap channel. We consider Alice and Eve to be strategic players interested in minimizing the resulting age of information at Bob's and Eve's, respectively. We frame the resulting system as two M/M/1 queues, fed by the remaining information and the eavesdropped data, respectively, for which we can exploit well-known results. The strategic interaction among the players is captured by a game-theoretic formulation, where Alice chooses her data generation rate and Eve controls the interception probability, both subject to a cost for their action. We obtain a characterization of the resulting Nash equilibria, exploring the conditions for their existence depending on the cost parameters. The most important finding of our analysis lies in the evaluation of the price of anarchy, which is found to be extremely high in the presence of multiple Nash equilibria. Thus, the application of distributed management ought to be carefully controlled to avoid inefficient outcomes
5G NR Support for UAV-Assisted Cellular Communication on Non-Terrestrial Network
No full textThe use of Unmanned Aerial Vehicles (UAVs) to provide cellular communication in rural areas, disaster-hit regions, or during temporary events is gaining increasing attention due to its flexible deployment and energy efficiency compared to fixed terrestrial infrastructures. However, UAVs experience significant challenges such as the limited wireless connectivity provided by Ka-band frequency, and their flying time is constrained by the energy consumed during the data transmission and the complexity of the Baseband Unit (BBU) implementation. Using different lower layer functional split options (e.g., 7-1, 7-2, 7-2x, and 7-3), this paper provides a theoretical and simulation analysis of the 5G New Radio (NR) physical layer specifications to achieve a fronthaul bandwidth that can be supported by the Ka-band. These functional split options are then compared in terms of fronthaul bandwidth, theoretical throughput, connection density, number of functions deployed at the UAV, and the energy consumption of the fronthaul transmission to determine which functional split option is better suited for a multi-layered Non-Terrestrial Network (NTN)
Network Time Synchronization as a Quantum Physical Layer Service
No full textIn the context of 6G architecture development, the concept of a softwarized (orchestration) continuum is a key pillar. Nevertheless, achieving complete softwarization of network functionalities, tasks, and operations presents inherent challenges, leading to critical trade-offs and limitations. This article explores a novel approach to address these issues by integrating quantum technologies and the Physical Layer Service Integration (PLSI) paradigm. Specifically, we propose the formulation and analysis of network synchronization as a quantum PLSI problem. Our study evaluates synchronization time offset in both conventional Precision Time Protocol (PTP) and quantum-based approaches within the network. We investigate the impact of various network conditions on the precision of PTP synchronization, ranging from nanoseconds under ideal circumstances to microseconds when utilizing virtual network devices. Further, we perform a simulation to generate frequency-entangled photon pairs to access nonlocal temporal correlations and calculate the time offsets. Our findings reveal that entanglement-based PLSI for network synchronization achieves precision at the picosecond level. These results emphasises the high precision achievable by interpreting the network synchronisation problem in the perspective of PLSI and not as a service of the softwarized continuum
Time Synchronization in Communication Networks: A Comparative Study of Quantum Technologies
No full textTime synchronization is crucial in the architecture of modern communication networks, supporting numerous high-stakes applications like financial transactions, autonomous vehicle control, and data center operations. While traditional time synchronization protocols, specifically the Network Time Protocol (NTP) and Precision Time Protocol (PTP), are reliable for various applications, they fall short in scenarios requiring ultra-high precision and resilience. To address these limitations, this paper provides a comprehensive comparative analysis of two emerging quantum technologies, namely Time-Correlated Entangled Photons (TCEP) and Optical Lattice Clocks (OLC). Using Monte Carlo simulations, we examined the synchronization in terms of the accuracy of these technologies under various noise conditions, revealing that while TCEP works perfectly in low-noise environments, its efficacy diminishes significantly with increasing noise levels. On the contrary, OLCs demonstrate consistent performance across various noise levels, making them more versatile for diverse application scenarios. This study is foundational for integrating quantum technologies in time synchronization for communication networks and sheds light on their merits and challenges. Our findings open new avenues for research in scalability, environmental resilience, and the development of hybrid quantum-classical timekeeping systems. Integrating quantum-enhanced time synchronization into a communication network will be the key step for achieving full-fledged Quantum Internet and quantum-enhanced communication networks
CoMon-DAS: A Framework for Efficient and Robust Dynamic Adaptive Streaming over NDN
No full textImplementing DASH, the most popular method for multimedia streaming, over NDN, a potential future Internet architecture, can substantially increase the network bandwidth utilization. However, inherent features of NDN can create new security risks for adaptive multimedia streaming. We propose a novel attack called Bitrate Oscillation Attack (BOA), which adversely exploits NDN's autonomous on-path caching and interest aggregation to unsettle DASH functionality. BOA forces the resolution and quality of video received by the attacked client to oscillate with high frequency and amplitude. Subsequently, we present CoMon-DAS, a framework for lightweight coordination that mitigates BOA and other attacks in NDN. Through extensive simulations, we demonstrate that BOA is very harmful for DAS over NDN, but can be significantly mitigated by CoMon-DAS
Technologies and infrastructures for a sustainable space
No full textThe space is going to become an unsafe place to operate. The amount of active and passive space objects (satellites and debris) that are concentrated in some orbits represents a treat. In such a crowded environment, spectrum management becomes more complex and the probability to operate with high level of interference increases. It is becoming more and more clear that actions are needed to make the space more sustainable. Much of the effort is nowadays in reducing the risk associated to the already produced “space junks”. This chapter outlines the need to design future missions through a common sustainability-prone strategy that aim to stop producing further pollution. The chapter describes the proposed strategy and key technologies to enable it
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