Ahan Kak

Bio: Ahan Kak is an academic researcher from Georgia Institute of Technology. The author has contributed to research in topics: Computer science & Ran. The author has an hindex of 5, co-authored 14 publications receiving 266 citations. Previous affiliations of Ahan Kak include Bell Labs & Veermata Jijabai Technological Institute.

6G and Beyond: The Future of Wireless Communications Systems

Abstract: 6G and beyond will fulfill the requirements of a fully connected world and provide ubiquitous wireless connectivity for all. Transformative solutions are expected to drive the surge for accommodating a rapidly growing number of intelligent devices and services. Major technological breakthroughs to achieve connectivity goals within 6G include: (i) a network operating at the THz band with much wider spectrum resources, (ii) intelligent communication environments that enable a wireless propagation environment with active signal transmission and reception, (iii) pervasive artificial intelligence, (iv) large-scale network automation, (v) an all-spectrum reconfigurable front-end for dynamic spectrum access, (vi) ambient backscatter communications for energy savings, (vii) the Internet of Space Things enabled by CubeSats and UAVs, and (viii) cell-free massive MIMO communication networks. In this roadmap paper, use cases for these enabling techniques as well as recent advancements on related topics are highlighted, and open problems with possible solutions are discussed, followed by a development timeline outlining the worldwide efforts in the realization of 6G. Going beyond 6G, promising early-stage technologies such as the Internet of NanoThings, the Internet of BioNanoThings, and quantum communications, which are expected to have a far-reaching impact on wireless communications, have also been discussed at length in this paper.

Designing Large-Scale Constellations for the Internet of Space Things With CubeSats

Abstract: The emergence of CubeSats as a viable means for realizing satellite networks at low costs has given rise to ubiquitous cyber–physical systems spanning air, ground, and space, in what is being recognized as the Internet of Space Things (IoST). IoST is expected to serve a wide variety of applications ranging from monitoring and reconnaissance to in-space backhauling. The pervasiveness of cyber–physical systems of this kind necessitates a robust constellation design, characterized by optimized coverage and consistent connectivity. Thus, optimal constellation design is of great importance to system architects. However, the constellation design frameworks prevalent today do not scale well beyond a few dozen satellites, adversely impacting the system’s operational abilities. To this end, the objective of this article is two fold. The primary objective is the development of a modular and highly customizable large-scale constellation design framework, with the secondary objective involving the use of the proposed framework for designing robust constellations for IoST, serving a wide variety of use cases ranging from global coverage to region-specific coverage scenarios. More specifically, the framework presented herein has been developed to optimize constellation design based on CubeSat density, as well as a rigorous mathematical characterization of coverage and connectivity parameters. Furthermore, an extensive set of performance comparisons with existing state-of-the-art constellations has been presented to validate the efficacy of the IoST constellations designed using the proposed framework. Finally, the impact of design parameter variations on the developed constellations has also been examined in great detail.

Performance Evaluation of SDN-Based Internet of Space Things

Abstract: The evolution of wireless communication is motivating the expansion of the scope of the Internet of Things (IoT) to an even greater scale. By 2020, it is anticipated that 50 billion devices will be connected to wireless networks. However, IoT is still limited in its reach owing to constraints associated with terrestrial networks. In an attempt to enhance the service and spatial scope of IoT, we have introduced the Internet of Space Things (IoST), a novel cyber-physical system that spans air, ground, and space. IoST leverages recent advancements, and our prior experience, in nanosatellite design, along with Software-defined Networking, and Network Function Virtualization to create an end-to-end platform for sensing and data delivery across the globe. In this paper, we review the key concepts of IoST and provide a comprehensive performance evaluation of the system. More specifically, we evaluate the impact of different orbital configurations and carrier frequencies (ranging from the S-band all the way to THz) on data rates, link latencies, next-hop availability and access durations. Further, we also present additional performance metrics in the context of a case-study involving end-to-end data delivery between two major cities. Based on the results obtained, we note the potential of IoST for a wide variety of use-cases including but not limited to remote sensing, cellular backhauling, and mission critical communications.

Large-Scale Constellation Design for the Internet of Space Things/CubeSats

Abstract: The increasing popularity of CubeSats has given rise to the possibility of ubiquitous cyber-physical systems, known as the Internet of Space Things/CubeSats, serving a wide variety of applications that range from monitoring and reconnaissance to in-space backhauling. Expectedly, such systems are characterized by the need for global coverage and consistent connectivity, and, thus, optimal constellation design is of great importance to system architects. The significance of optimal constellation design comes from the fact that it has a direct impact on the cost, scalability, and effectiveness of the system. However, the constellation design methodologies present today do not scale well beyond a few dozen satellites, severely impacting the system's potential. To this end, a large-scale optimal constellation design framework is presented in this paper. The proposed framework is geared towards achieving global coverage with robust connectivity, and can scale well for several hundred CubeSats, making it a perfect fit for the Internet of Space Things/CubeSats. Further, a performance comparison is conducted with several state-of-the-art constellations to validate the efficacy of our constellation design.

6G and Beyond: The Future of Wireless Communications Systems

Abstract: 6G and beyond will fulfill the requirements of a fully connected world and provide ubiquitous wireless connectivity for all. Transformative solutions are expected to drive the surge for accommodating a rapidly growing number of intelligent devices and services. Major technological breakthroughs to achieve connectivity goals within 6G include: (i) a network operating at the THz band with much wider spectrum resources, (ii) intelligent communication environments that enable a wireless propagation environment with active signal transmission and reception, (iii) pervasive artificial intelligence, (iv) large-scale network automation, (v) an all-spectrum reconfigurable front-end for dynamic spectrum access, (vi) ambient backscatter communications for energy savings, (vii) the Internet of Space Things enabled by CubeSats and UAVs, and (viii) cell-free massive MIMO communication networks. In this roadmap paper, use cases for these enabling techniques as well as recent advancements on related topics are highlighted, and open problems with possible solutions are discussed, followed by a development timeline outlining the worldwide efforts in the realization of 6G. Going beyond 6G, promising early-stage technologies such as the Internet of NanoThings, the Internet of BioNanoThings, and quantum communications, which are expected to have a far-reaching impact on wireless communications, have also been discussed at length in this paper.

The Road Towards 6G: A Comprehensive Survey

Abstract: As of today, the fifth generation (5G) mobile communication system has been rolled out in many countries and the number of 5G subscribers already reaches a very large scale. It is time for academia and industry to shift their attention towards the next generation. At this crossroad, an overview of the current state of the art and a vision of future communications are definitely of interest. This article thus aims to provide a comprehensive survey to draw a picture of the sixth generation (6G) system in terms of drivers, use cases, usage scenarios, requirements, key performance indicators (KPIs), architecture, and enabling technologies. First, we attempt to answer the question of "Is there any need for 6G?" by shedding light on its key driving factors, in which we predict the explosive growth of mobile traffic until 2030, and envision potential use cases and usage scenarios. Second, the technical requirements of 6G are discussed and compared with those of 5G with respect to a set of KPIs in a quantitative manner. Third, the state-of-the-art 6G research efforts and activities from representative institutions and countries are summarized, and a tentative roadmap of definition, specification, standardization, and regulation is projected. Then, we identify a dozen of potential technologies and introduce their principles, advantages, challenges, and open research issues. Finally, the conclusions are drawn to paint a picture of "What 6G may look like?". This survey is intended to serve as an enlightening guideline to spur interests and further investigations for subsequent research and development of 6G communications systems.

The Road Towards 6G: A Comprehensive Survey

Abstract: As of today, the fifth generation (5G) mobile communication system has been rolled out in many countries and the number of 5G subscribers already reaches a very large scale It is time for academia and industry to shift their attention towards the next generation At this crossroad, an overview of the current state of the art and a vision of future communications are definitely of interest This article thus aims to provide a comprehensive survey to draw a picture of the sixth generation (6G) system in terms of drivers, use cases, usage scenarios, requirements, key performance indicators (KPIs), architecture, and enabling technologies First, we attempt to answer the question of “Is there any need for 6G?” by shedding light on its key driving factors, in which we predict the explosive growth of mobile traffic until 2030, and envision potential use cases and usage scenarios Second, the technical requirements of 6G are discussed and compared with those of 5G with respect to a set of KPIs in a quantitative manner Third, the state-of-the-art 6G research efforts and activities from representative institutions and countries are summarized, and a tentative roadmap of definition, specification, standardization, and regulation is projected Then, we identify a dozen of potential technologies and introduce their principles, advantages, challenges, and open research issues Finally, the conclusions are drawn to paint a picture of “What 6G may look like?” This survey is intended to serve as an enlightening guideline to spur interests and further investigations for subsequent research and development of 6G communications systems

6G Internet of Things: A Comprehensive Survey

Abstract: The sixth generation (6G) wireless communication networks are envisioned to revolutionize customer services and applications via the Internet of Things (IoT) towards a future of fully intelligent and autonomous systems. In this article, we explore the emerging opportunities brought by 6G technologies in IoT networks and applications, by conducting a holistic survey on the convergence of 6G and IoT. We first shed light on some of the most fundamental 6G technologies that are expected to empower future IoT networks, including edge intelligence, reconfigurable intelligent surfaces, space-air-ground-underwater communications, Terahertz communications, massive ultra-reliable and low-latency communications, and blockchain. Particularly, compared to the other related survey papers, we provide an in-depth discussion of the roles of 6G in a wide range of prospective IoT applications via five key domains, namely Healthcare Internet of Things, Vehicular Internet of Things and Autonomous Driving, Unmanned Aerial Vehicles, Satellite Internet of Things, and Industrial Internet of Things. Finally, we highlight interesting research challenges and point out potential directions to spur further research in this promising area.

Survey on 6G Frontiers: Trends, Applications, Requirements, Technologies and Future Research

Abstract: Emerging applications such as Internet of Everything, Holographic Telepresence, collaborative robots, and space and deep-sea tourism are already highlighting the limitations of existing fifth-generation (5G) mobile networks. These limitations are in terms of data-rate, latency, reliability, availability, processing, connection density and global coverage, spanning over ground, underwater and space. The sixth-generation (6G) of mobile networks are expected to burgeon in the coming decade to address these limitations. The development of 6G vision, applications, technologies and standards has already become a popular research theme in academia and the industry. In this paper, we provide a comprehensive survey of the current developments towards 6G. We highlight the societal and technological trends that initiate the drive towards 6G. Emerging applications to realize the demands raised by 6G driving trends are discussed subsequently. We also elaborate the requirements that are necessary to realize the 6G applications. Then we present the key enabling technologies in detail. We also outline current research projects and activities including standardization efforts towards the development of 6G. Finally, we summarize lessons learned from state-of-the-art research and discuss technical challenges that would shed a new light on future research directions towards 6G.