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Antonella Molinaro

Publications and source records attributed to Antonella Molinaro.

11 recordsLinked to original sources

Proactive URLLC Adaptation for Connected Vehicles Through ML-Based Channel Prediction

Connected and automated vehicles (CAVs) are expected to increasingly rely on 5G and future 6G ultra-reliable and low-latency communication (URLLC) services to support safety-critical and time-sensitive applications. Since wireless link conditions can vary rapidly in urban vehicular environments, proactively adapting service parameters based on future channel conditions is essential to maintain service continuity and reliability. In this paper, we investigate the use of machine learning (ML) techniques for channel quality prediction in vehicular URLLC scenarios. Specifically, we evaluate deep neural network (DNN) and long short-term memory (LSTM) models to forecast future channel conditions and enable proactive service adaptation with minimized performance degradation. The analysis is conducted using realistic simulations combining the SUMO traffic simulator and the Sionna-RT ray-tracing framework in a real urban environment reconstructed from OpenStreetMap data. Results show that ML-based prediction significantly outperforms approaches relying solely on past channel measurements and achieves performance close to the ideal case in which future channel conditions are perfectly known in advance. These findings demonstrate the potential of ML-driven prediction techniques to enhance the reliability and robustness of URLLC services for connected vehicular systems.

cs.NI

Reinforcement Learning-based Task Offloading in the Internet of Wearable Things

Over the years, significant contributions have been made by the research and industrial sectors to improve wearable devices towards the Internet of Wearable Things (IoWT) paradigm. However, wearables are still facing several challenges. Many stem from the limited battery power and insufficient computation resources available on wearable devices. On the other hand, with the popularity of smart wearables, there is a consistent increase in the development of new computationally intensive and latency-critical applications. In such a context, task offloading allows wearables to leverage the resources available on nearby edge devices to enhance the overall user experience. This paper proposes a framework for Reinforcement Learning (RL)-based task offloading in the IoWT. We formulate the task offloading process considering the tradeoff between energy consumption and task accomplishment time. Moreover, we model the task offloading problem as a Markov Decision Process (MDP) and utilize the Q-learning technique to enable the wearable device to make optimal task offloading decisions without prior knowledge. We evaluate the performance of the proposed framework through extensive simulations for various applications and system configurations conducted in the ns-3 network simulator. We also show how varying the main system parameters of the Q-learning algorithm affects the overall performance in terms of average task accomplishment time, average energy consumption, and percentage of tasks offloaded.

cs.LG

Exploiting Repetitions and Interference Cancellation for the 6G-V2X Sidelink Autonomous Mode

In recent years, the Third Generation Partnership Project (3GPP) has developed the new radio-vehicle-to-everything (NR-V2X) sidelink standard, to enable direct communication between connected and autonomous vehicles (CAVs). Users can autonomously select radio resources for their transmissions with the Mode 2 channel access scheme, which can also operate under out-of-coverage conditions. However, Mode 2 performance is hindered by interference and packet collisions arising from dynamic mobile environments and limitations in assessing radio resource availability. The 3GPP specifications allow transmitting multiple copies of the same packet to improve reliability, though at the cost of increased channel congestion. This paper proposes to leverage receivers equipped with successive interference cancellation (SIC) capabilities, to exploit packet repetitions. Specifically, once a packet is successfully decoded the interfering contribution carried by repetitions can be cancelled from future or past received signals, enabling the decoding of new packets. Extensive highway scenario simulations demonstrate that the proposed solution significantly outperforms the legacy Mode 2 scheme, especially under high interference conditions, achieving improvements exceeding 100% in some cases.

cs.NI

XR Offloading Across Multiple Time Scales: The Roles of Power, Temperature, and Energy

Extended reality (XR) devices, commonly known as wearables, must handle significant computational loads under tight latency constraints. To meet these demands, they rely on a combination of on-device processing and edge offloading. This letter focuses on offloading strategies for wearables by considering their impact across three time scales: instantaneous power consumption, short-term temperature fluctuations, and long-term battery duration. We introduce a comprehensive system model that captures these temporal dynamics, and propose a stochastic and stationary offloading strategy, called TAO (for temperature-aware offloading), designed to minimize the offloading cost while adhering to power, thermal, and energy constraints. Our performance evaluation, leveraging COMSOL models of real-world wearables, confirms that TAO reduces offloading cost by over 35% compared to state-of-the-art approaches, without violating the wearable operational limits.

cs.NI

A novel approach for MBSFN Area Formation aided by D2D Communications for eMBB Service Delivery in 5G NR Systems

Forthcoming 5G New Radio (NR) systems will be asked to handle a huge number of devices accessing or delivering "resource-hungry" and high-quality services. In view of this, the new 5G Radio Access Technology (RAT) aims to support, in next releases, Multimedia Broadcast/Multicast Service Single Frequency Network (MBSFN) to enable the simultaneous delivery of the same content to a set of users covered by different cells. According to MBSFN, all cells belonging to the same MBSFN Area are synchronized in time and the MBSFN transmission occurs over the same radio resources. In such a way, the same content flow is delivered by several cells to all the receivers in the MBSFN Area. A further means to enhance the network coverage and provide high data rate and low latency in future 5G-enabled MBSFN networks is Device-to-Device (D2D) connectivity. Along these lines, in this paper we propose a D2D-aided MBSFN Area Formation (D2D-MAF) algorithm to dynamically create MBSFN Areas with the aim to improve the system aggregate data rate while satisfying all user requests. The proposed D2D-MAF foresees that users could receive the service through either MBSFN, or D2D, or unicast transmissions. Performance evaluation results, carried out under a wide range of conditions, testify to the high effectiveness of the proposed algorithm.

cs.NI

Age of Information in Multi-hop Networks with Priorities

Age of Information is a new metric used in real-time status update tracking applications. It measures at the destination the time elapsed since the generation of the last received packet. In this paper, we consider the co-existence of critical and noncritical status updates in a two-hop system, for which the network assigns different scheduling priorities. Specifically, the high priority is reserved to the packets that traverse the two nodes, as they experience worse latency performance. We obtain the distribution of the age and its natural upper bound termed peak age. We provide tight upper and lower bounds for priority updates and the exact expressions for the non-critical flow of packets with a general service distribution. The results give fundamental insights for the design of age-sensitive multi-hop systems.

cs.NI

Effective RAT Selection Approach for 5G Dense Wireless Networks

Dense Networks (DenseNet) and Multi-Radio Access Technologies (Multi-RATs) are considered as key features of the emerging fifth generation (5G) wireless systems. A Multi-RAT DenseNet is characterized by a very dense deployment of low-power base stations (BSs) and by a multi-tier architecture consisting of heterogeneous radio access technologies. Such a network aims to guarantee high data-rates, low latency and low energy consumption. Although the usage of a Multi RAT DenseNet solves problems such as coverage holes and low performance at the cell edge, frequent and unnecessary RAT handovers may occur with a consequent high signaling load. In this work, we propose an effective RAT selection algorithm that efficiently manages the RAT handover procedure by \emph{(i)} choosing the most suitable RAT that guarantees high system and user performance, and \emph{(ii)} reducing unnecessary handover events. In particular, the decision to trigger a handover is based on a new system parameter named Reference Base Station Efficiency (RBSE). This parameter takes into account metrics related to both the system and the user: the BS transmitted power, the BS traffic load and the users' spectral efficiency. We compare, by simulation, the proposed scheme with the standardized 3GPP policies. Results show that the proposed RAT selection scheme significantly reduces the number of handovers and the end-to-end delay while maintaining high system throughput and user spectral efficiency.

cs.NI

Effective Resource Allocation in 5G-Satellite Networks

This paper addresses the radio resource management of multicast transmissions in the emerging fifth generation satellite systems (5G-Satellite). A subgrouping approach is exploited to provide video streaming services to satellite users by splitting any multicast group into subgroups. This allows an effective exploitation of multi-user diversity according to the experienced channel conditions and the achievement of a high throughput level. The main drawback is the high computational cost usually related to the selection of the optimal subgroup configuration. In this paper we propose a low-complexity subgrouping algorithm that achieves performance close to optimum. Our solution is suitable for implementation in practical systems, such as Satellite-Long Term Evolution (S-LTE), since the computational cost does not depend on the multicast group size and the number of available resources. Through simulation campaigns conducted in different radio propagation and multicast group environments, the effectiveness of the proposed subgroup formation scheme is assessed.

cs.NI

Efficient Data Uploading Supported by D2D Communications in LTE-A Systems

The reference scenario in this paper is a single cell in a Long Term Evolution-Advanced (LTE-A) system, where multiple user equipments (UEs) aim at uploading some data to a central server or to the Cloud. The traditional uploading technique used in cellular systems, i.e., with separate links from each UE to the eNodeB, is compared to innovative \textit{relay-based} schemes that exploit Device-to-Device (D2D) communications between two (or more) UEs in proximity to each other. Differences in the channel quality experienced by the UEs offer an opportunity to develop D2D-based solutions, where \textit{(i)} the UE with a poor direct link to the eNodeB will forward data to a nearby UE over a high-quality D2D link; and \textit{(ii)} the receiving UE then uploads its own generated data and the relayed data to the eNodeB over a good uplink channel. A straightforward gain in the data uploading time can be obtained for the first UE. To extend the benefits, also to the relaying UE, enhanced D2D-based solutions are proposed that decrease the uploading time of this UE based on the cooperative sharing of the resources allocated by the eNodeB to the cooperating devices. Finally, preliminary results are also presented for a multihop study case, where a chain of devices exploits D2D communications to upload data to the eNodeB.

cs.NI

Evaluating the Performance of Multicast Resource Allocation Policies over LTE Systems

This paper addresses a multi-criteria decision method properly designed to effectively evaluate the most performing strategy for multicast content delivery in Long Term Evolution (LTE) and beyond systems. We compared the legacy conservative-based approach with other promising strategies in literature, i.e., opportunistic multicasting and subgroup-based policies tailored to exploit different cost functions, such as maximum throughput, proportional fairness and the multicast dissatisfaction index (MDI). We provide a comparison among above schemes in terms of aggregate data rate (ADR), fairness and spectral efficiency. We further design a multi-criteria decision making method, namely TOPSIS, to evaluate through a single mark the overall performance of considered strategies. The obtained results show that the MDI subgrouping strategy represents the most suitable approach for multicast content delivery as it provides the most promising trade-off between the fairness and the throughput achieved by the multicast members.

cs.NI

Efficient Spectrum Management Exploiting D2D Communication in 5G Systems

In the future standardization of the 5G networks, in Long Term Evolution (LTE) Release 13 and beyond, Device-to-Device communications (D2D) is recognized as one of the key technologies that will support the 5G architecture. In fact, D2D can be exploited for different proximity-based services (ProSe) where the users discover their neighbors and benefit form different services like social applications, advertisement, public safety, and warning messages. In such a scenario, the aim is to manage in a proper way the radio spectrum and the energy consumption to provide high Quality of Experience (QoE) and better Quality of Services (QoS). To reach this goal, in this paper we propose a novel D2D-based uploading scheme in order to decrease the amount of radio resources needed to upload to the eNodeB a certain multimedia content. As a further improvement, the proposed scheme enhances the energy consumption of the users in the network, without affects the content uploading time. The obtained results show that our scheme achieves a gain of about 35\% in term of mean radio resources used with respect to the standard LTE cellular approach. In addition, it is also 40 times more efficient in terms of energy consumption needed to upload the multimedia content.

cs.NI