Effects of Heterogeneous Mobility on D2D- and Drone-Assisted Mission-Critical MTC in 5G
mcMTC is starting to play a central role in the industrial Internet of Things ecosystem and have the potential to create high-revenue businesses, including intelligent transportation systems, energy/ smart grid control, public safety services, and high-end wearable applications. Consequently, in the 5G of wireless networks, mcMTC have imposed a wide range of requirements on the enabling technology, such as low power, high reliability, and low latency connectivity. Recognizing these challenges, the recent and ongoing releases of LTE systems incorporate support for low-cost and enhanced coverage, reduced latency, and high reliability for devices at varying levels of mobility. In this article, we examine the effects of heterogeneous user and device mobility - produced by a mixture of various mobility patterns - on the performance of mcMTC across three representative scenarios within a multi-connectivity 5G network. We establish that the availability of alternative connectivity options, such as D2D links and drone-assisted access, helps meet the requirements of mcMTC applications in a wide range of scenarios, including industrial automation, vehicular connectivity, and urban communications. In particular, we confirm improvements of up to 40 percent in link availability and reliability with the use of proximate connections on top of the cellular-only baseline.
In the modern world, a high-speed wireless Internet connection is a necessity rather than a luxury. To improve the efficiency of Wi-Fi networks in dense deployment, a novel amendment to the Wi-Fi standard, namely IEEE 802.11ax introduces Orthogonal frequency-division multiple access (OFDMA). In contrast to legacy Wi-Fi, where performance of a station to a considerable degree depends on rate control, aggregation and other decision-making algorithms implemented at the station, in 11ax networks it is the access point that schedules channel time and specifies transmission parameters for both uplink and downlink. Although OFDMA scheduling in 11ax has much in common with that in cellular networks, e.g. LTE, 11ax has some peculiarities, especially for uplink transmission. Focusing on such peculiarities, in this paper, we investigate the scheduling problem in 11ax, propose a set of schedulers for 11ax, compare their performance and determine the gain achievable by the usage of OFDMA.
In this paper, we consider the problem of radio resource scheduling for Industrial Internet and Tactile Internet. Both paradigms - being revolutionary drivers of 5G - are tightly connected with low-latency communications (i.e. latency of the order of 10 ms or even less). We give an original mathematical statement of the radio resource scheduling problem and propose a novel algorithm which solves this problem using the dynamic programming method. With simulations we show that the proposed algorithm outperforms ones found in literature both in terms of goodput (i.e. the amount of data delivered to users within delay budget) and number of users with satisfied QoS requirements. Finally, we discuss how the developed algorithm can be implemented in real networking equipment.
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.
Today, the rapid adoption of mobile social networking is changing how and where humans communicate. As a result, in recent years we have been increasingly moving from physical (e.g., face-to-face) to virtual interaction. However, there is also a new emerging category of social applications that take advantage of both worlds, that is, using virtual interaction to enhance physical interaction. This novel form of networking is enabled by D2D communication between/among the laptops, smartphones, and wearables of persons in proximity of each other. Unfortunately, it has remained limited by the fact that most people are simply not aware of the many potential virtual opportunities in their proximity at any given time. This is a result of the very real digital privacy and security concerns surrounding direct communication between "stranger" devices. Fortunately, these concerns can be mitigated with the help of a centralized trusted entity, such as a cellular service provider, which can not only authenticate and protect the privacy of devices involved into D2D communication, but also facilitate the discovery of device capabilities and their available content. This article offers an extensive research summary behind this type of "cellular-assisted" D2D communication, detailing the enabling technology and its implementation, relevant usage scenarios, security challenges, and user experience observations from large-scale deployments.
Recently standardized millimeter-wave (mmWave) band 3GPP New Radio systems are expected to bring extraordinary rates to the air interface efficiently providing commercial-grade enhanced mobile broadband services in hotspot areas. One of the challenges of such systems is efficient offloading of the data from access points (AP) to the network infrastructure. This task is of special importance for APs installed in remote areas with no transport network available. In this paper, we assess the packet level performance of mmWave technology for cost-efficient backhauling of remote 3GPP NR APs connectivity “islands”. Using a queuing system with arrival processes of the same priority competing for transmission resources, we assess the aggregated and per-AP packet loss probability as a function environmental conditions, mmWave system specifics, and generated traffic volume. We show that the autocorrelation in aggregated traffic provides a significant impact on service characteristics of mmWave backhaul and needs to be compensated by increasing either emitted power or the number of antenna array elements. The effect of autocorrelation in the per-AP traffic and background traffic from other APs also negatively affects the per-AP packet loss probability. However, the effect is of different magnitude and heavily depends on the load fraction of per-AP traffic in the aggregated traffic stream. The developed model can be used to parameterize mmWave backhaul links as a function of the propagation environment, system design, and traffic conditions.
Generalized error-locating codes are discussed. An algorithm for calculation of the upper bound of the probability of erroneous decoding for known code parameters and the input error probability is given. Based on this algorithm, an algorithm for selection of the code parameters for a specified design and input and output error probabilities is constructed. The lower bound of the probability of erroneous decoding is given. Examples of the dependence of the probability of erroneous decoding on the input error probability are given and the behavior of the obtained curves is explained.
The dynamics of a two-component Davydov-Scott (DS) soliton with a small mismatch of the initial location or velocity of the high-frequency (HF) component was investigated within the framework of the Zakharov-type system of two coupled equations for the HF and low-frequency (LF) fields. In this system, the HF field is described by the linear Schrödinger equation with the potential generated by the LF component varying in time and space. The LF component in this system is described by the Korteweg-de Vries equation with a term of quadratic influence of the HF field on the LF field. The frequency of the DS soliton`s component oscillation was found analytically using the balance equation. The perturbed DS soliton was shown to be stable. The analytical results were confirmed by numerical simulations.
Radiation conditions are described for various space regions, radiation-induced effects in spacecraft materials and equipment components are considered and information on theoretical, computational, and experimental methods for studying radiation effects are presented. The peculiarities of radiation effects on nanostructures and some problems related to modeling and radiation testing of such structures are considered.