Wirelessly powered urban crowd sensing over wearables:trading energy for data

Abstract In this article, we put forward the paradigm of mobile crowd sensing based on ubiquitous wearable devices carried by human users. The key challenge for mass user involvement in prospective urban crowd sensing applications, such as monitoring of large-scale phenomena (e.g., traffic congestion and air pollution levels), is the appropriate sources of motivation. We thus advocate for the use of wireless power transfer provided in exchange for sensed data to incentivize the owners of wearables to participate in collaborative data collection. Based on this construction, we develop a novel concept of wirelessly powered crowd sensing and offer the corresponding network architecture considerations together with a systematic review of wireless charging techniques to support implementation. Further, we contribute a detailed system-level feasibility study that reports on the achievable performance levels for the envisioned setup. Finally, the underlying energy- data trading mechanisms are discussed, and the work concludes with outlining open research opportunities

Enabling simultaneous cooling and data transmission in the terahertz band for board-to-board communications

Abstract A system enabling simultaneous cooling and board-to-board communications is proposed and analyzed. It is shown that hollow pipes used in computer cooling systems can be applied for communications with extreme data rates at distances up to tens of centimeters. This is done by using wireless communications in the terahertz frequency band, 0.1–10 THz. The experiments were performed in order to observe how straight and curved pipes of different diameters and lengths affect THz signals propagating inside the pipes. The measured pulses were recorded and used in numerical evaluation of bit error rate and throughput taking into account the effect of all possible combinations of N previous symbols. The numerical results show the dependency of the intersymbol interference on the delay profile of the channel and on the symbol period. The results demonstrate that even with simple on–off keying modulation the throughput reaches few terabits per second with qualitatively low bit error rates. This enables communications between rate-hungry electronics inside computers such as central and graphical processing units while simultaneously providing the cooling functionality

Effects of blockage in deploying mmWave drone base stations for 5g networks and beyond

Due to their unconstrained mobility and capability to carry goods or equipment, unmanned aerial vehicles (UAVs) or drones are considered as a part of the fifth-generation (5G) wireless networks and become attractive candidates to carry a base station (BS). As 5G requirements apply to a broad range of uses cases, it is of particular importance to satisfy those during spontaneous and temporary events, such as a marathon or a rural fair. To be able to support these scenarios, mobile operators need to deploy significant radio access resources quickly and on demand. Accordingly, by focusing on 5G cellular networks, we investigate the use of drone-assisted communication, where a drone is equipped with a millimeter-wave (mmWave) BS. Being a key technology for 5G, mmWave is able to facilitate the provisioning of the desired per-user data rates as drones arrive at the service area whenever needed. Therefore, in order to maximize the benefits of mmWave-drone-BS utilization, this paper proposes a methodology for its optimized deployment, which delivers the optimal height, coordinates, and coverage radius of the drone-BS by taking into account the human body blockage effects over a mmWave-specific channel model

Channel modeling and performance analysis of airplane-satellite terahertz band communications

Abstract Wireless connectivity in airplanes is becoming more important, demanded, and common. One of the largest bottlenecks with the in-flight Internet is that the airplane is far away from both the satellites and the ground base stations during most of the flight time. Maintaining a reliable and high-rate wireless connection with the airplane over such a long-range link thus becomes a challenge. Microwave frequencies allow for long link distances but lack the data rate to serve up to several hundreds of potential onboard customers. Higher bands in the millimeter-wave spectrum (30 GHz–300 GHz) have, therefore, been utilized to overcome the bandwidth limitations. Still, the per-user throughput with state-of-the-art millimeter-wave systems is an order of magnitude lower than the one available with terrestrial wireless networks. In this paper, we take a step further and study the channel characteristics for the terahertz band (THz, 0.3 THz–10 THz) in order to map the feasibility of this band for aviation. We first propose a detailed channel model for aerial THz communications taking into account both the non-flat Earth geometry and the main features of the frequency-selective THz channel. We then apply this model to estimate the characteristics of aerial THz links in different conditions. We finally determine the altitudes where the use of airplane-to-satellite THz connection becomes preferable over the airplane-to-ground THz link. Our results reveal that the capacity of the airborne THz link may reach speeds ranging from 50–150 Gbps, thus enabling cellular-equivalent data rates to the passengers and staff during the entire flight

Last meter indoor terahertz wireless access:performance insights and implementation roadmap

Abstract The terahertz band, 0.1–10 THz, has sufficient resources not only to satisfy the 5G requirements of 10 Gb/s peak data rate but to enable a number of tempting rate-greedy applications. However, the terahertz band brings novel challenges, never addressed at lower frequencies. Among others, the scattering of terahertz waves from any object, including walls and furniture, and ultra-wideband highly directional links lead to fundamentally new propagation and interference structures. In this article, we review the recent progress in terahertz propagation modeling, and antenna and testbed designs, and propose a step-by-step roadmap for wireless terahertz Ethernet extension for indoor environments. As a side effect, the described concept provides a second life to the currently underutilized Ethernet infrastructure by using it as a universally available backbone. By applying real terahertz band propagation, reflection, and scattering measurements as well as ray-tracing simulations of a typical office, we analyze two representative scenarios at 300 GHz and 1.25 THz frequencies, illustrating that extremely high rates can be achieved with realistic system parameters at room scales

The impact of interference from the side lanes on mmWave/THz band V2V communication systems with directional antennas

Abstract Communications systems operating in the millimeter-wave (mmWave) and terahertz (THz) band have been recently suggested to enable high data-rate vehicle-to-vehicle (V2V) communications in 5G and beyond wireless networks. However, massive deployment of such systems may lead to significant interference, affecting the performance of information transmission. While the multipath interference caused by the signal reflections from the road has been extensively discussed in the literature, the interference caused by the vehicles on the side lanes has been insufficiently studied so far. In this paper, using a combination of measurement, simulation, and analytical methods, we comprehensively characterize the interference from the side lanes in two typical deployments including highway and urban road environments for millimeter-wave and low terahertz bands. Both the multipath interference and direct interference from the transmitting vehicles on the side lanes are taken into account. As a result of our study, we reveal that: the interference from the side lanes can be well approximated using two-dimensional stochastic models without any significant loss of accuracy; and even when highly directional antennas are used there are special spatial configurations, where the interference may greatly affect the performance of the communication systems. We lately apply the developed models to estimate the signal-to-interference ratio and link capacity of mmWave/THz band V2V communications

Exploring synergy between communications, caching, and computing in 5G-grade deployments

Decisive progress in 5G mobile technology, fueled by a rapid proliferation of computation- hungry and delay-sensitive services, puts economic pressure on the research community to rethink the fundamentals of underlying networking architectures. Along these lines, the first half of this article offers a first-hand tutorial on the most recent advances in content-centric networking, emerging user applications, as well as enabling system architectures. We establish that while significant progress has been made along the individual vectors of communications, caching, and computing, together with some promising steps in proposing hybrid functionalities, the ultimate synergy behind a fully integrated solution is not nearly well understood. Against this background, the second half of this work carefully brings into perspective additional important factors, such as user mobility patterns, aggressive application requirements, and associated operator deployment capabilities, to conduct comprehensive system-level analysis. Furthermore, supported by a full-fledged practical trial on a live cellular network, our systematic findings reveal the most dominant factors in converged 5G-grade communications, caching, and computing layouts, as well as indicate the natural optimization points for system operators to leverage the maximum available benefits

Accuracy assessment and cross-validation of LPWAN propagation models in urban scenarios

Abstract With the proliferation of machine-to-machine (M2M) communication in the course of the last decade, the importance of low-power wide-area network (LPWAN) technologies intensifies. However, the abundance of accurate propagation models proposed for these systems by standardization bodies, vendors, and research community hampers the deployment planning. In this paper, we question the selection of accurate propagation models for Narrowband IoT (NB-IoT), LoRaWAN, and Sigfox LPWAN technologies, based on extensive measurement campaign in two mid-size European cities. Our results demonstrate that none of the state-of-the-art models can accurately describe the propagation of LPWAN radio signals in an urban environment. For this reason, we propose enhancements to the selected models based on our experimental measurements. Performing the fine-tuning of the propagation models for one of the cities, we select Ericsson Urban (NB-IoT, LoRaWAN) and 3GPP (Sigfox) models as the ones providing the closest match. Finally, we proceed to perform cross-validation of the propagation models using the data set for another city. The tuned models demonstrate an excellent match with the real data in the cross-validation phase. They outperform their competitors by at least 20–80% in terms of relative deviation from the measured signal levels presenting the accurate option for NB-IoT, LoRaWAN, and Sigfox deployments planning in mid-size cities

On unified vehicular communications and radar sensing in millimeter-wave and low terahertz bands

Abstract Future smart vehicles will incorporate high-data-rate communications and high-resolution radar sensing capabilities operating in the millimeter- wave and higher frequencies. These two systems are preparing to share and reuse many common functionalities, such as steerable millimeter- wave antenna arrays. Motivated by this growing overlap, which is advanced further by space and cost constraints, the vehicular community is pursuing a vision of unified vehicular communications and radar sensing that represents a major paradigm shift for next-generation connected and self-driving cars. This article outlines a path to materialize this decisive transformation. We begin by reviewing the latest developments in hybrid vehicular communications and radar systems, and then propose a concept of unified channel access over millimeter-wave and higher frequencies. Our supporting system-level performance characterization relies upon real-life measurements and extensive ray-based modeling to confirm the significant improvements brought by our proposal to mitigating the interference and deafness effects. Since our results aim to open the door to unified vehicular communications and radar sensing, we conclude by outlining the potential research directions in this rapidly developing field

LPWAN coverage assessment planning without explicit knowledge of base station locations

Abstract An assessment of radio network coverage, usually in the form of a measurement campaign, is essential for multi-base-station (multi-BS) network deployment and maintenance. It can be conducted by a network operator or its served consumers. However, the number of measurement points and their locations may not be known in advance for an efficient and accurate evaluation. The main goal of this study is to propose a new methodology for understanding the selection of measurement points during coverage and signal quality assessment. It is particularly tailored to multi-BS low-power wide-area network (LPWAN) deployments without explicit knowledge of BS locations. To this aim, we first conduct a large-scale measurement campaign for three popular LPWAN technologies, namely, NB-IoT, Sigfox, and LoRaWAN. Utilizing this baseline data, we develop a procedure for identifying the minimum set of measurement points for the coverage assessment with a given accuracy as well as study which interpolation algorithms produce the lowest approximation error. Our results demonstrate that a random choice of measurement points is on par with their deterministic selection. Out of the candidate interpolation algorithms, Kriging method offers attractive performance in terms of the absolute error for NB-IoT deployments. By contrast, for Sigfox and LoRaWAN infrastructures, less complex techniques, such as Natural-neighbor, Linear interpolation, or Inverse-Distance Weighting, can achieve comparable (and occasionally even better) accuracy levels