Multi-layer Utilization of Beamforming in Millimeter Wave MIMO Systems

mmWave frequencies ranging between (30-300GHz) have been considered the perfect solution to the scarcity of bandwidth in the traditional sub-6GHz band and to the ever increasing demand of many emerging applications in today\u27s era. 5G and beyond standards are all considering the mmWave as an essential part of there networks. Beamforming is one of the most important enabling technologies for the mmWave to compensate for the huge propagation lose of these frequencies compared to the sub-6GHz frequencies and to ensure better spatial and spectral utilization of the mmWave channel space. In this work, we tried to develop different techniques to improve the performance of the systems that use mmWave. In the physical layer, we suggested several hybrid beamforming architectures that both are relatively simple and spectrally efficient by achieving fully digital like spectral efficiency (bits/sec/Hz). For the mobility management, we derived the expected degradation that can affect the performance of a special type of beamforming that is called the Random Beamforming (RBF) and optimized the tunable parameters for such systems when working in different environments. Finally, in the networking layer, we first studied the effect of using mmWave frequencies on the routing performance comparing to the performance achieved when using sub-6 GHz frequencies. Then we developed a novel opportunistic routing protocol for Mobile Ad-Hoc Networks (MANET) that uses a modified version of the Random Beamforming (RBF) to achieve better end to end performance and to reduce the overall delay in delivering data from transmitting nodes to the intended receiving nodes. From all these designs and studies, we conclude that mmWave frequencies and their enabling technologies (i.e. Beamforming, massive MIMO, ...etc.) are indeed the future of wireless communicatons in a high demanding world of Internet of Things (IoT), Augmented Reality (AR), Virtual Reality (VR), and self driving cars

Hybrid Spectrum Sharing in mmWave Cellular Networks

While spectrum at millimeter wave (mmWave) frequencies is less scarce than at traditional frequencies below 6 GHz, still it is not unlimited, in particular if we consider the requirements from other services using the same band and the need to license mmWave bands to multiple mobile operators. Therefore, an efficient spectrum access scheme is critical to harvest the maximum benefit from emerging mmWave technologies. In this paper, we introduce a new hybrid spectrum access scheme for mmWave networks, where data is aggregated through two mmWave carriers with different characteristics. In particular, we consider the case of a hybrid spectrum scheme between a mmWave band with exclusive access and a mmWave band where spectrum is pooled between multiple operators. To the best of our knowledge, this is the first study proposing hybrid spectrum access for mmWave networks and providing a quantitative assessment of its benefits. Our results show that this approach provides major advantages with respect to traditional fully licensed or fully unlicensed spectrum access schemes, though further work is needed to achieve a more complete understanding of both technical and non technical implications

Low-latency Networking: Where Latency Lurks and How to Tame It

While the current generation of mobile and fixed communication networks has been standardized for mobile broadband services, the next generation is driven by the vision of the Internet of Things and mission critical communication services requiring latency in the order of milliseconds or sub-milliseconds. However, these new stringent requirements have a large technical impact on the design of all layers of the communication protocol stack. The cross layer interactions are complex due to the multiple design principles and technologies that contribute to the layers' design and fundamental performance limitations. We will be able to develop low-latency networks only if we address the problem of these complex interactions from the new point of view of sub-milliseconds latency. In this article, we propose a holistic analysis and classification of the main design principles and enabling technologies that will make it possible to deploy low-latency wireless communication networks. We argue that these design principles and enabling technologies must be carefully orchestrated to meet the stringent requirements and to manage the inherent trade-offs between low latency and traditional performance metrics. We also review currently ongoing standardization activities in prominent standards associations, and discuss open problems for future research

High-Altitude Configuration of Non-Terrestrial Telecommunication Network using Optical Wireless Technologies

Non-terrestrial communication technologies will become a key component for the development of future 6th generation (6G) networks. Potentials, implementation prospects, problems and solutions for non-terrestrial telecommunications remain open areas for future research. The article discusses the use of millimeter and optical wavelengths in various configurations of multilevel space communications using LEO satellites, stratospheric platforms and unmanned repeaters. The comparison of the capacity of the Shannon channel for various multi-level scenarios of the satellite communication line is carried out. The directions of research are analyzed to ensure the continuity of communication, adaptation to weather conditions, and achieving a throughput of up to 100 Gbit/s

Wireless 60 GHz Rack to Rack Communication in a Data Center Environment

Data centers play an increasingly important role in processing the large amount of information generated in today\u27s society. An enormous amount of growth in the computational demands of data center applications has stimulated the creation of warehouse scale data centers, holding servers that number in the thousands. As the number of servers within a data center grows, the interconnecting infrastructure becomes of paramount importance. Present day interconnects are formed using either copper wire in a twisted pair configuration or through the use of fiber optic cables. One of the main concerns with the scalability of a data center\u27s interconnecting network is the power consumption. Large power hungry switches at the aggregation and core levels make up a significant portion of a data centers power portfolio and cannot be overlooked. Furthermore, large bundles of wires both reduce the air flow within data centers and are costly to replace and maintain. This cabling complexity problem limits cooling effectiveness and exacerbates the power consumption challenges. Recent advancements in the unlicensed 60 GHz spectrum have given rise to transceivers that can support high bandwidth links, comparable to wired links found in most data centers. These wireless links also exhibit promising characteristics such as spatial reusability which make them suitable within a data center environment. By taking advantage of emerging 60 GHz wireless technologies, data centers can utilize these high speed wireless links to satisfy bandwidth demands while simultaneously reducing their power consumption and cabling requirements. This thesis evaluates the benefits in terms of energy-efficiency of using 60 GHz wireless links to replace wire line links within a data center by modeling a completely wireless data center. The physical layer design and associated MAC layer will be investigated to support this wireless centric design. The proposed wireless architecture will be compared against traditional hierarchical data center architectures and evaluated based upon several performance metrics such as throughput, latency, and overall energy efficiency

Hybrid Satellite-Terrestrial Communication Networks for the Maritime Internet of Things: Key Technologies, Opportunities, and Challenges

With the rapid development of marine activities, there has been an increasing number of maritime mobile terminals, as well as a growing demand for high-speed and ultra-reliable maritime communications to keep them connected. Traditionally, the maritime Internet of Things (IoT) is enabled by maritime satellites. However, satellites are seriously restricted by their high latency and relatively low data rate. As an alternative, shore & island-based base stations (BSs) can be built to extend the coverage of terrestrial networks using fourth-generation (4G), fifth-generation (5G), and beyond 5G services. Unmanned aerial vehicles can also be exploited to serve as aerial maritime BSs. Despite of all these approaches, there are still open issues for an efficient maritime communication network (MCN). For example, due to the complicated electromagnetic propagation environment, the limited geometrically available BS sites, and rigorous service demands from mission-critical applications, conventional communication and networking theories and methods should be tailored for maritime scenarios. Towards this end, we provide a survey on the demand for maritime communications, the state-of-the-art MCNs, and key technologies for enhancing transmission efficiency, extending network coverage, and provisioning maritime-specific services. Future challenges in developing an environment-aware, service-driven, and integrated satellite-air-ground MCN to be smart enough to utilize external auxiliary information, e.g., sea state and atmosphere conditions, are also discussed