Search

Multicast/broadcast delivery is a critical challenge of future 6G mobile networks where massive Internet of Things (IoT) deployment and extended reality multimedia such as teleportation are target application scenarios. Non-terrestrial networks (NTNs) are considered essential for the success of 6G, which aims to provide true “global” services by extending mobile access worldwide, thus overcoming the coverage limit of current terrestrial networks (TNs). This article discusses how the main distinguishing features of NTNs can be effectively exploited for 6G multicasting. Furthermore, in line with the evolution of future 6G networks toward softwarized systems, we evaluate the potential of using the softwarization paradigm in the heterogeneous TN–NTN architecture to deliver multicast services. [ABSTRACT FROM AUTHOR]

Emerging communication network applications require a location accuracy of less than 1 m in more than 95% of the service area. For this purpose, 5G New Radio (NR) technology is designed to facilitate high-accuracy continuous localization. In 5G systems, the existence of high-density small cells and the possibility of the device-to-device (D2D) communication between mobile terminals paves the way for cooperative positioning applications. From the standardization perspective, D2D technology is already under consideration (5G NR Release 16) for ultra-dense networks enabling cooperative positioning and is expected to achieve the ubiquitous positioning of below one-meter accuracy, thereby fulfilling the 5G requirements. In this survey, the strengths and weaknesses of D2D as an enabling technology for cooperative cellular positioning are analyzed (including two D2D approaches to perform cooperative positioning); lessons learned and open issues are highlighted to serve as guidelines for future research. [ABSTRACT FROM AUTHOR]

Multicasting is becoming more and more important in the Internet of Things (IoT) and wearable applications (e.g., high definition video streaming, virtual reality gaming, public safety, among others) that require high bandwidth efficiency and low energy consumption. In this regard, millimeter wave (mmWave) communications can play a crucial role to efficiently disseminate large volumes of data as well as to enhance the throughput gain in fifth-generation (5G) and beyond networks. There are, however, challenges to face in view of providing multicast services with high data rates under the conditions of short propagation range caused by high path loss at mmWave frequencies. Indeed, the strong directionality required at extremely high frequency bands excludes the possibility of serving all multicast users via a single transmission. Therefore, multicasting in directional systems consists of a sequence of beamformed transmissions to serve all multicast group members, subgroup by subgroup. This paper focuses on multicast data transmission optimization in terms of throughput and, hence, of the energy efficiency of resource-constrained devices such as wearables, running their resource-hungry applications. In particular, we provide a means to perform the beam switching and propose a radio resource management (RRM) policy that can determine the number and width of the beams required to deliver the multicast content to all interested users. Achieved simulation results show that the proposed RRM policy significantly improves network throughput with respect to benchmark approaches. It also achieves a high gain in energy efficiency over unicast and multicast with fixed predefined beams. [ABSTRACT FROM AUTHOR]

The era of the fifth-generation (5G) New Radio (NR) technology has just begun, and its promises to substantially improve the system performance have turned into reality. The 5G NR enabled Non-Terrestrial Network (NTN) is almost upon us and will represent an effective solution to provide services anytime, anywhere, and over wider coverage areas. In this context, high throughput satellite systems with advanced multi-beam transmissions have gained significant attention owing to their ability to boost the system capacity through beam frequency re-use, increased user data rates, and system spectral efficiency. In this paper, we propose a novel radio resource management scheme, named Single-Frequency Multi-Beam Transmission (SF-MBT), for efficient delivery of the enhanced Mobile Broadband (eMBB) services over the 5G NR multi-beam NTN systems. The main thinking is to group beams into the dedicated Beam Areas, wherein a certain content flow is delivered via simultaneous multi-beam transmissions over the same radio resources without causing inter-beam interference. A simulation campaign is conducted under different scenarios to assess the effectiveness of the proposed SF-MBT algorithm as compared to the current schemes based on frequency reuse. System-wide performance is evaluated in terms of the aggregate data rate, mean throughput, and system spectral efficiency. [ABSTRACT FROM AUTHOR]

To date, group-oriented communications have been mainly exploited for delivering multimedia services in human-oriented communications while, in future fifth generation (5G) cellular networks, objects will be the main target. Internet of Things (IoT) will undoubtedly play a key role in 5G networks, wherein massive machine-type communications (mMTC) feature a use case as crucial as challenging since cellular IoT connections are predicted to grow heavily in the next future. To boost capacity and energy efficiency, the 5G network can leverage device-to-device (D2D) communications which are recognized as an effective offloading technique. This is achieved thanks to the fact that, in legacy D2D communications, data are directly sent from one device to another, avoiding the crossing of the network. Obviously, the distributed nature of such a communication paradigm and the inherent broadcast nature of the wireless channel make it necessary to think how to secure the so called “sidelink” transmissions. This work proposes a protocol for the efficient and reliable management of multicast services in a 5G-oriented IoT scenario, in which security is a crucial requirement to be met. The proposed protocol is tailored to Narrowband IoT (NB-IoT) and makes use of D2D communications with the aim of improving network efficiency and optimizing network resource utilization. In addition, cyber security and social trustworthiness mechanisms are exploited to secure D2D communications. [ABSTRACT FROM AUTHOR]

The ever-increasing demand for high-quality video contents over mobile networks is pushing Telco operators towards the design of new delivery solutions. 3GPP has defined Multimedia Broadcast/Multicast Service Single Frequency Network (MBSFN) to enable the simultaneous transmission of the same content within multiple cells over the same radio resources, with improved network scalability and spectral efficiency. This paper proposes a Dynamic MBSFN Area Formation (DMAF) algorithm that suitably selects the adjacent synchronized cells to include in any MBSFN Area of a 5G New Radio (NR) system to the purpose of increasing the system Aggregate Data Rate while avoiding user outage. The proposed algorithm dynamically creates MBSFN Areas by leveraging the multicast “subgrouping” paradigm for Scalable Video Coding (SVC) traffic delivery. Cells are grouped into different MBSFN Areas and any cell can be part of Disjoint MBSFN Area or Overlapping MBSFN Area. Each Overlapping MBSFN Area broadcasts a Base video flow at a given quality level to all users, whereas Enhancement Layers are only delivered to users with better channel conditions. Simulation results testify to the better performance achieved by the proposed algorithm w.r.t. other schemes available from the literature. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The forthcoming fifthgeneration (5G) mobile wireless system is likely to lead to an increasingly heterogeneous data-demand pattern, including a small number of high-data-rate mobile broadband links and a large number of low-data-rate Internet of Things (IoT) applications. Aspects that govern seamless mobility between different access technologies, cell tiers, cell sectors, and frequency bands will be sensitive to the mobility model of the people, their devices, and the machines. An understanding of such entities will play a fundamental role in the future standardization and exploitation of the 5G technologies. In this article, we provide a comprehensive and general overview about existing mobility models that are useful to characterizing movement patterns across multiple distance and population scales. In doing so, all the models are critically discussed, providing strengths and weaknesses. Finally, open issues and critical design choices are highlighted to serve as guidelines for future research on this topic. [ABSTRACT FROM PUBLISHER]

The 5G mobile networks are expected to offer higher degrees of radio access heterogeneity across a wide range of technologies (LTE, WiFi, mmWave, etc.), which operate in both licensed and unlicensed spectrum providing dissimilar data rates and coverage. In light of the stringent requirements in terms of resource and energy efficiency, the performance optimization of such heterogeneous 5G systems becomes an involved task that demands abundant information on the states of users to solve a complex, large-scale optimization problem. However, the unpredictable mobility of communicating entities, including dual mobility of D2D partners, may lead to a rapid deviation from the initial, optimized system state and thus requires frequent re-optimizations of the entire network. In this article, we aim to deliver a comprehensive tutorial on the implications of system- wide energy and resource management with the emphasis on its time-dependent behavior. Proposing a novel network-centric 5G optimization framework, we employ insights from the random walk and Markov chain theories, and also confirm our findings with an extensive system-level simulation campaign. These results reveal an exponential performance degradation rate that primarily depends on the average user speeds. Together with reporting the divergence exponents for different 5G system configurations, we also provide practical insights into how to exploit them in order to non-incrementally improve the thro [ABSTRACT FROM PUBLISHER]

The number and variety of mobile multicast applications are growing at an unprecedented and unanticipated pace. Mobile network providers are in front of a dramatic increase in multicast traffic load, and this growth is forecasted to continue in fifth-generation (5G) networks. The major challenges come from the fact that multicast traffic not only targets groups of end-user devices; it also involves machine-type communications (MTC) for the Internet of Things (IoT). The increase in the MTC load, predicted for 5G, calls into question the effectiveness of the current multimedia broadcast multicast service (MBMS). The aim of this paper is to provide a survey of 5G challenges in the view of effective management of multicast applications, and to identify how to enhance the mobile network architecture to enable multicast applications in future 5G scenarios. By accounting for the presence of both human and machine-related traffic, strengths and weaknesses of the state-of-the-art achievements in multicasting are critically analyzed to provide guidelines for future research on 5G networks and more conscious design choices. [ABSTRACT FROM PUBLISHER]

Platooning is the first step toward fully autonomous driving, which is deemed as one of the most representative fifth-generation (5G) use cases. Spacing and speed in a platoon of vehicles are regulated by a fully automated control system that relies on updated vehicles? kinematics data. In this article, we investigate the potential of long-term evolution (LTE) device-todevice (D2D) communications for data dissemination in the platoon. Exploiting pooled LTE resources and the coordination by the in-front vehicle of the platoon, the proposed solution is shown to fulfill the ultralow latency requirements of messaging in the platoon. As a further advantage, our proposal is able to provide spatial reuse of LTE resources among members of the same platoon and of different platoons, thus drastically reducing the capacity demand. [ABSTRACT FROM PUBLISHER]

Next-generation device-to-device (D2D) communication technology, in which a cellular network assists proximal users at all stages of their interaction, is rapidly developing. Previous research has thoroughly characterized D2D performance aspects from discovery to connection establishment, security, and service continuity; however, prospective D2Denabled applications and services envision highly opportunistic device contacts as a consequence of unpredictable human user mobility. Therefore, mobility's impact on D2D communication requires careful investigation to understand the practical operational efficiency of future cellular-assisted D2D systems. This article offers a first-hand tutorial on various implications of D2D mobility across different user movement patterns and mobility-related parameters and proposes an assessment methodology for D2D-enabled systems. The rigorous system-level evaluation conducted for this study delivers important conclusions on the effects of user mobility in emerging D2D-centric systems. [ABSTRACT FROM PUBLISHER]

Driven by the unprecedented increase of mobile data traffic, D2D communications technology is rapidly moving into the mainstream of the 5G networking landscape. While D2D connectivity originally emerged as a technology enabler for public safety services, it is likely to remain at the heart of the 5G ecosystem by spawning a wide diversity of proximate applications and services. In this work, we argue that the widespread adoption of the direct communications paradigm is unlikely without embracing the concepts of trust and social-aware cooperation between end users and network operators. However, such adoption remains conditional on identifying adequate incentives that engage humans and their connected devices in a plethora of collective activities. To this end, the mission of our research is to advance the vision of social-aware and trusted D2D connectivity, as well as to facilitate its further adoption. We begin by reviewing the various types of underlying incentives with the emphasis on sociality and trust, discuss these factors specifically for humans and for networked devices (machines), and also propose a novel framework allowing construction of much needed incentive-aware D2D applications. Our supportive system-level performance evaluations suggest that trusted and social-aware direct connectivity has the potential to decisively augment network performance. We conclude by outlining the future perspectives of its development across the research and standardization sectors. [ABSTRACT FROM PUBLISHER]

Multimedia content delivery over satellite systems is considered as a promising service in emerging 5G networks. The aim of this paper is to design a novel radio resource management algorithm for efficiently managing multicast multimedia content transmission over satellite network. The proposed approach performs the spectrum management on a per-group basis, by splitting multicast terminals into different subgroups according to the experienced channel qualities. We demonstrate that subgrouping policy defined by the authors as multicast subgrouping-maximum satisfaction index (MS-MSI), based on a new metric (i.e., MSI), overcomes the weakness of the previous techniques proposed in the literature and provides the best tradeoff between user throughput and fairness. As a further result, we demonstrate that MS-MSI is robust to the long propagation delay of satellite links. An extensive simulation campaign has been conducted by considering several satellite environments. [ABSTRACT FROM PUBLISHER]