Millimeter-Wave Cellular Wireless Networks: Potentials and Challenges
05 Feb 2014-Vol. 102, Iss: 3, pp 366-385
TL;DR: Measurements and capacity studies are surveyed to assess mmW technology with a focus on small cell deployments in urban environments and it is shown that mmW systems can offer more than an order of magnitude increase in capacity over current state-of-the-art 4G cellular networks at current cell densities.
Abstract: Millimeter-wave (mmW) frequencies between 30 and 300 GHz are a new frontier for cellular communication that offers the promise of orders of magnitude greater bandwidths combined with further gains via beamforming and spatial multiplexing from multielement antenna arrays. This paper surveys measurements and capacity studies to assess this technology with a focus on small cell deployments in urban environments. The conclusions are extremely encouraging; measurements in New York City at 28 and 73 GHz demonstrate that, even in an urban canyon environment, significant non-line-of-sight (NLOS) outdoor, street-level coverage is possible up to approximately 200 m from a potential low-power microcell or picocell base station. In addition, based on statistical channel models from these measurements, it is shown that mmW systems can offer more than an order of magnitude increase in capacity over current state-of-the-art 4G cellular networks at current cell densities. Cellular systems, however, will need to be significantly redesigned to fully achieve these gains. Specifically, the requirement of highly directional and adaptive transmissions, directional isolation between links, and significant possibilities of outage have strong implications on multiple access, channel structure, synchronization, and receiver design. To address these challenges, the paper discusses how various technologies including adaptive beamforming, multihop relaying, heterogeneous network architectures, and carrier aggregation can be leveraged in the mmW context.
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01 Oct 2016
TL;DR: Important facets of assured communications systems include agility with respect to channel and spectrum, protection from attack and tampering, resilience in the face of disruptions, and interoperability.
Abstract: Success in complex missions, whether in the civilian, military, or mixed sectors, depends on agile organizations adapting their enterprise approaches to suit the purposes and circumstances at hand, and being able and willing to communicate necessary information. Case studies of complex endeavors in theaters including warfare, terrorism, and response to natural disasters have shown that communication failures are a very significant cause of adverse consequences, often including overall mission failure. Communication failures can be behavioral ones, exacerbated by inappropriate organizational choices. They can also arise from shortfalls in system design and technology. Enterprise approaches that are decentralized and network-enabled to varying degrees have differing propensities to communicate necessary information in diverse circumstances. They also have a complex and varying interplay with the enterprise's information and communications technology, and varying resilience to communications disruption. While more agile organizations can make up for communications shortfalls to an extent, there is no substituted for assured communications capabilities. In this connection, the ability to communicate relatively small amounts of information reliably can be much more important than the ability to transmit large multimedia files with high throughput. Important facets of assured communications systems include agility with respect to channel and spectrum, protection from attack and tampering, resilience in the face of disruptions, and interoperability. In some cases the goals can be achieved with appropriate policy, and in others with new technology development.
2 citations
01 Jan 2015
TL;DR: This dissertation focuses on four aspects of modern wireless networks: modeling and analysis of interference in single-hop wireless networks, characterizing the tradeoffs between the communication performance of wireless transmission and the computational load on the systems used to process such transmissions, the optimization of wireless multiple-access networks when using cost functions that are based on the analytical findings in this dissertation.
Abstract: Role of Interference and Computational Complexity in Modern Wireless Networks: Analysis, Optimization, and Design by Salvatore Talarico Doctor of Philosophy in Electrical Engineering West Virginia University Matthew C. Valenti, Ph.D., Chair Owing to the popularity of smartphones, the recent widespread adoption of wireless broadband has resulted in a tremendous growth in the volume of mobile data traffic, and this growth is projected to continue unabated. In order to meet the needs of future systems, several novel technologies have been proposed, including cooperative communications, cloud radio access networks (RANs) and very densely deployed small-cell networks. For these novel networks, both interference and the limited availability of computational resources play a very important role. Therefore, the accurate modeling and analysis of interference and computation is essential to the understanding of these networks, and an enabler for more efficient design. This dissertation focuses on four aspects of modern wireless networks: (1) Modeling and analysis of interference in single-hop wireless networks, (2) Characterizing the tradeoffs between the communication performance of wireless transmission and the computational load on the systems used to process such transmissions, (3) The optimization of wireless multiple-access networks when using cost functions that are based on the analytical findings in this dissertation, and (4) The analysis and optimization of multi-hop networks, which may optionally employ forms of cooperative communication. The study of interference in single-hop wireless networks proceeds by assuming that the random locations of the interferers are drawn from a point process and possibly constrained to a finite area. Both the information-bearing and interfering signals propagate over channels that are subject to path loss, shadowing, and fading. A flexible model for fading, based on the Nakagami distribution, is used, though specific examples are provided for Rayleigh fading. The analysis is broken down into multiple steps, involving subsequent averaging of the performance metrics over the fading, the shadowing, and the location of the interferers with the aim to distinguish the effect of these mechanisms that operate over different time scales. The analysis is extended to accommodate diversity reception, which is important for the understanding of cooperative systems that combine transmissions that originate from different locations. Furthermore, the role of spatial correlation is considered, which provides insight into how the performance in one location is related to the performance in another location. While it is now generally understood how to communicate close to the fundamental limits implied by information theory, operating close to the fundamental performance bounds
2 citations
Cites background from "Millimeter-Wave Cellular Wireless N..."
...While these two assumptions are widely used to design, model and analyze cellular networks, they do not capture adequately the dependency of the fading and path loss on the link distance, which is extremely important to properly model and analyze densely deployed and millimeter wave cellular networks [68,69]....
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15 Apr 2018
TL;DR: This paper presents an initial access scheme applicable to FDD bands, where second-order channel statistics are exploited through digital beamforming, and shows good results of the initial access time even in very low signal to noise ratio conditions.
Abstract: Millimeter-wave frequency bands pose significant challenges to cellular communications because of their increased path loss and lower robustness against signal obstruction, reflection or blocking phenomena. Beamforming is generally perceived as the most convenient solution to overcome this issue, usually relying on a combination of beam scanning and reciprocity-based precoding. However, channel reciprocity cannot be assumed in FDD spectrum bands, hence forcing initial access to rely solely on beam scanning with the subsequent impact on initial access time. This paper presents an initial access scheme applicable to FDD bands, where second-order channel statistics are exploited through digital beamforming. Link-level and Monte Carlo simulations are performed using the QuaDRiGa channel model, showing good results of the initial access time even in very low signal to noise ratio conditions.
2 citations
Cites background from "Millimeter-Wave Cellular Wireless N..."
...The latter ones, commonly referred to as “millimeter-wave” (mm-wave) frequencies, pose significant challenges as per their increased path loss and lower resilience to obstruction, blocking and reflection [1], [2]....
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01 Jan 2019
TL;DR: The goal of this dissertation is to develop an accurate data delivery framework and address design and analysis challenges, including initial access, link scheduling, resource allocation, and routing, for 5G mobile communication networks that are envisioned to provide universal high-rate coverage and seamless user experience.
Abstract: The ever-increasing proliferation of smart devices, the introduction of new user-oriented mission-critical applications, together with an exponential rise in mobile data demand and usage, have been creating a significant burden on the existing cellular networks. Indeed, fifth generation (5G) mobile communications will need to be a paradigm shift that includes very high carrier frequencies with massive bandwidths, extreme base station and device densities, and unprecedented numbers of antennas. The goal of this dissertation is to develop an accurate data delivery framework and address design and analysis challenges, including initial access, link scheduling, resource allocation, and routing, for 5G mobile communication networks that are envisioned to provide universal high-rate coverage and seamless user experience. First, this dissertation considers communication networks operating in millimeter wave (mm-wave) bands, where the availability of abundant spectrum makes mm-wave a prominent candidate technology for 5G mobile communications. Highly directional transmission, which is essential for the exploitation of mm-wave bands to compensate for high propagation loss, necessitates a specific design of mm-wave initial cell discovery, as conventional omnidirectional broadcast may fail in delivering cell discovery information. To address this issue, a tractable analytical framework is proposed to characterize beamformed cell discovery, where several representative broadcast schemes are studied to investigate discovery performance including latency and overhead. Leveraging the analysis of the discovery performance, this dissertation provides key ix insights for the design of mm-wave beamformed cell discovery: Single beam exhaustive scan optimizes latency but leads to overhead penalty, and multiple beam simultaneous scan significantly reduces overhead and provides the flexibility to achieve a trade-off between latency and overhead. Then, the focus of this dissertation shifts to emerging technologies that exploit spatial multiplexing for mobile communications. By enabling a large number of links to be simultaneously transmitted, directional antenna arrays with beamforming are promising to reach unprecedented levels of spatial isolation. To achieve the high efficiency of spatial reuse in improving system performance, an optimization problem that maximizes the achievable data rate of a multihop heterogeneous network, considering both downlink and uplink transmissions on backhaul and access links, is formulated. The optimization problem is systematically decomposed and demonstrated as NP-hard, and a heuristic joint scheduling and resource allocation scheme, including link scheduling, transmission duration allocation, and power allocation, is proposed to maximize the achievable data rate. In conjunction with an efficient path selection algorithm, it is demonstrated that the data rate closely approaches the theoretical optimum, yet with significantly lower latency. Finally, this dissertation considers the data delivery in mobile communication networks, with a special focus on vehicle-to-everything (V2X) networks, in which the data delivery relies on the carry-and-forward strategy of vehicle-to-vehicle communications assisted by vehicle-to-infrastructure communications that are capable of bridging long-range vehicular connectivity. Nevertheless, V2X communications necessitate a specific design of multihop routing to enhance data delivery performance. To address the issue, this dissertation provides a tractable analytical framework to investigate the data delivery performance in V2X networks takx ing into account latency and data rate as performance metrics. Based on a theoretical analysis, both global and distributed optimization problems that minimize latency while maximizing data rate are formulated. The proposed optimization problems are verified to be convex and then solved using convex optimization theory, followed by corresponding global and distributed multihop routing algorithms to select the optimal route for data delivery. In particular, the proposed routing algorithms provide considerable improvement over classical vehicular routing algorithms, in the sense of minimizing latency while maximizing data rate, and shed design insights into the multihop routing algorithm for data delivery in 5G mobile communication networks.
2 citations
Cites background from "Millimeter-Wave Cellular Wireless N..."
...5G cellular communications are embracing mm-wave frequencies between 6 and 300 GHz, where the availability of large chunks of untapped bandwidth makes it possible to achieve the demand for gigabits per second data rates (Gbps) [10, 32]....
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...With the wide coverage of frequencies ranging from 6 and 300 GHz, mm-wave bands have drawn significant attention for the next generation mobile communication systems [10, 32], where the available bandwidths are much wider than today’s cellular allocations [11, 33]....
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Posted Content•
TL;DR: In this paper, the authors developed a new framework for measuring and comparing the accuracy of any wireless interference models used in the analysis and design of wireless networks, based on a new index that assesses the ability of the interference model to correctly predict harmful interference events, i.e., link outages.
Abstract: We develop a new framework for measuring and comparing the accuracy of any wireless interference models used in the analysis and design of wireless networks. Our approach is based on a new index that assesses the ability of the interference model to correctly predict harmful interference events, i.e., link outages. We use this new index to quantify the accuracy of various interference models used in the literature, under various scenarios such as Rayleigh fading wireless channels, directional antennas, and blockage (impenetrable obstacles) in the network. Our analysis reveals that in highly directional antenna settings with obstructions, even simple interference models (e.g., the classical protocol model) are accurate, while with omnidirectional antennas, more sophisticated and complex interference models (e.g., the classical physical model) are necessary. Our new approach makes it possible to adopt the appropriate interference model of adequate accuracy and simplicity in different settings.
2 citations
References
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Book•
15 Jan 1996
TL;DR: WireWireless Communications: Principles and Practice, Second Edition is the definitive modern text for wireless communications technology and system design as discussed by the authors, which covers the fundamental issues impacting all wireless networks and reviews virtually every important new wireless standard and technological development, offering especially comprehensive coverage of the 3G systems and wireless local area networks (WLANs).
Abstract: From the Publisher:
The indispensable guide to wireless communicationsnow fully revised and updated!
Wireless Communications: Principles and Practice, Second Edition is the definitive modern text for wireless communications technology and system design. Building on his classic first edition, Theodore S. Rappaport covers the fundamental issues impacting all wireless networks and reviews virtually every important new wireless standard and technological development, offering especially comprehensive coverage of the 3G systems and wireless local area networks (WLANs) that will transform communications in the coming years. Rappaport illustrates each key concept with practical examples, thoroughly explained and solved step by step.
Coverage includes:
An overview of key wireless technologies: voice, data, cordless, paging, fixed and mobile broadband wireless systems, and beyond
Wireless system design fundamentals: channel assignment, handoffs, trunking efficiency, interference, frequency reuse, capacity planning, large-scale fading, and more
Path loss, small-scale fading, multipath, reflection, diffraction, scattering, shadowing, spatial-temporal channel modeling, and microcell/indoor propagation
Modulation, equalization, diversity, channel coding, and speech coding
New wireless LAN technologies: IEEE 802.11a/b, HIPERLAN, BRAN, and other alternatives
New 3G air interface standards, including W-CDMA, cdma2000, GPRS, UMTS, and EDGE
Bluetooth wearable computers, fixed wireless and Local Multipoint Distribution Service (LMDS), and other advanced technologies
Updated glossary of abbreviations and acronyms, and a thorolist of references
Dozens of new examples and end-of-chapter problems
Whether you're a communications/network professional, manager, researcher, or student, Wireless Communications: Principles and Practice, Second Edition gives you an in-depth understanding of the state of the art in wireless technologytoday's and tomorrow's.
17,102 citations
"Millimeter-Wave Cellular Wireless N..." refers background in this paper
...Also, the human body and many outdoor materials being very reflective, allow them to be important scatterers for mmW propagation [28], [30]....
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...However, these measurements were performed in an outdoor campus setting with much lower building density and greater opportunities for LOS connectivity than would be found in a typical urban deployment....
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...Despite the potential of mmW cellular systems, there are a number of key challenges to realizing the vision of cellular networks in these bands: • Range and directional communication: Friis’ transmis- sion law [54] states that the free space omnidirectional path loss grows with the square of the…...
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TL;DR: The motivation for new mm-wave cellular systems, methodology, and hardware for measurements are presented and a variety of measurement results are offered that show 28 and 38 GHz frequencies can be used when employing steerable directional antennas at base stations and mobile devices.
Abstract: The global bandwidth shortage facing wireless carriers has motivated the exploration of the underutilized millimeter wave (mm-wave) frequency spectrum for future broadband cellular communication networks. There is, however, little knowledge about cellular mm-wave propagation in densely populated indoor and outdoor environments. Obtaining this information is vital for the design and operation of future fifth generation cellular networks that use the mm-wave spectrum. In this paper, we present the motivation for new mm-wave cellular systems, methodology, and hardware for measurements and offer a variety of measurement results that show 28 and 38 GHz frequencies can be used when employing steerable directional antennas at base stations and mobile devices.
6,708 citations
"Millimeter-Wave Cellular Wireless N..." refers background or methods in this paper
...In both 28- and 73-GHz measurements, each point was classified as either being in a NLOS or LOS situation, based on a manual classification made at the time of the measurements; see [26] and [28]–[33]....
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...• Empirical NYC: These curves are based on the omnidirectional path loss predicted by our linear model (1) for the mmW channel with the parameters from Table 1, as derived from the directional measurements in [26]....
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...Details of the measurements can be found in [26], [28]– [33], [81]....
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...This tremendous potential has led to considerable recent interest in mmW cellular both in industry [7]–[9], [18], [19] and academia [20]–[26], with a growing belief that mmW bands will play a significant role in beyond 4G and 5G cellular systems [27]....
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...In particular, we survey our own measurements [26], [28]–[33] made in New York City (NYC) in both 28- and 73-GHz bands and the statistical models for the channels developed in [34]....
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TL;DR: The gains in multiuser systems are even more impressive, because such systems offer the possibility to transmit simultaneously to several users and the flexibility to select what users to schedule for reception at any given point in time.
Abstract: Multiple-input multiple-output (MIMO) technology is maturing and is being incorporated into emerging wireless broadband standards like long-term evolution (LTE) [1]. For example, the LTE standard allows for up to eight antenna ports at the base station. Basically, the more antennas the transmitter/receiver is equipped with, and the more degrees of freedom that the propagation channel can provide, the better the performance in terms of data rate or link reliability. More precisely, on a quasi static channel where a code word spans across only one time and frequency coherence interval, the reliability of a point-to-point MIMO link scales according to Prob(link outage) ` SNR-ntnr where nt and nr are the numbers of transmit and receive antennas, respectively, and signal-to-noise ratio is denoted by SNR. On a channel that varies rapidly as a function of time and frequency, and where circumstances permit coding across many channel coherence intervals, the achievable rate scales as min(nt, nr) log(1 + SNR). The gains in multiuser systems are even more impressive, because such systems offer the possibility to transmit simultaneously to several users and the flexibility to select what users to schedule for reception at any given point in time [2].
5,158 citations
"Millimeter-Wave Cellular Wireless N..." refers background in this paper
...These multiple antenna systems can be used to form very high gain, electrically steerable arrays, fabricated at the base station (BS), in the skin of a cellphone, or even within a chip [6], [10]–[17]....
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TL;DR: In this article, the authors describe five technologies that could lead to both architectural and component disruptive design changes: device-centric architectures, millimeter wave, massive MIMO, smarter devices, and native support for machine-to-machine communications.
Abstract: New research directions will lead to fundamental changes in the design of future fifth generation (5G) cellular networks. This article describes five technologies that could lead to both architectural and component disruptive design changes: device-centric architectures, millimeter wave, massive MIMO, smarter devices, and native support for machine-to-machine communications. The key ideas for each technology are described, along with their potential impact on 5G and the research challenges that remain.
3,711 citations
TL;DR: The technical and business arguments for femtocells are overview and the state of the art on each front is described and the technical challenges facing femtocell networks are described and some preliminary ideas for how to overcome them are given.
Abstract: The surest way to increase the system capacity of a wireless link is by getting the transmitter and receiver closer to each other, which creates the dual benefits of higher-quality links and more spatial reuse. In a network with nomadic users, this inevitably involves deploying more infrastructure, typically in the form of microcells, hot spots, distributed antennas, or relays. A less expensive alternative is the recent concept of femtocells - also called home base stations - which are data access points installed by home users to get better indoor voice and data coverage. In this article we overview the technical and business arguments for femtocells and describe the state of the art on each front. We also describe the technical challenges facing femtocell networks and give some preliminary ideas for how to overcome them.
3,298 citations
"Millimeter-Wave Cellular Wireless N..." refers background in this paper
...Heterogeneous networks, or HetNets, have been one of the most active research areas in cellular standards bodies in the last five years [45], [48], [67], [68], with the main focus being intercell interference coordination and load balancing....
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