TOWARDS 6G THROUGH SDN AND NFV-BASED SOLUTIONS FOR TERRESTRIAL AND NON-TERRESTRIAL NETWORKS A Dissertation Presented to The Academic Faculty By Ahan Kak In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the School of Electrical and Computer Engineering Georgia Institute of Technology May 2021 © Ahan Kak 2021 TOWARDS 6G THROUGH SDN AND NFV-BASED SOLUTIONS FOR TERRESTRIAL AND NON-TERRESTRIAL NETWORKS Thesis committee: Dr. Ian F. Akyildiz (Advisor) Dr. Chuanyi Ji School of Electrical and Computer School of Electrical and Computer Engineering (Formerly) Engineering Georgia Institute of Technology Georgia Institute of Technology Dr. Raghupathy Sivakumar (Chair) Dr. Henry L. Owen School of Electrical and Computer School of Electrical and Computer Engineering Engineering Georgia Institute of Technology Georgia Institute of Technology Dr. Mary Ann Weitnauer Dr. Andy Sun School of Electrical and Computer School of Industrial & Systems Engineering Engineering Georgia Institute of Technology Georgia Institute of Technology Date approved: April 6, 2021 To my family, for their endless love, support, and encouragement. ACKNOWLEDGMENTS I would like to begin by expressing my deepest gratitude to my advisor, Dr. Ian F. Aky- ildiz. I am extremely grateful to him for giving me the life-changing opportunity of joining his lab. His unparalleled vision and boundless passion have been integral in setting me on the path to academic success. Like a guiding light that shines through stormy seas, Prof. Akyildiz’s limitless wisdom has always led the way forward, even in the most difficult of times. His incredible work ethic has been a constant source of inspiration for me throughout this journey, one that has been greatly enriched by his immense knowledge and extensive experience. Being an international student is never easy, but Prof. Akyildiz’s warmth, benev- olence, and kindness are what made Atlanta home. I have been extremely fortunate to be advised in not just academics, but also life, by one of the greatest scientists of our generation, and for that I am forever indebted. I would also like to express my profound appreciation to all the faculty members and administrative staffs of the School of Electrical and Computer Engineering at the Georgia Institute of Technology for their help throughout my Ph.D. A special thanks goes to Dr. Raghupathy Sivakumar and Dr. Mary Ann Weitnauer, who provided constructive and valu- able suggestions on my research work and are a key part of my Ph.D. Defense Reading Committee. Moreover, I am thankful to Dr. Chuanyi Ji, Dr. Henry L. Owen, and Dr. Andy Sun, who are an integral part of my Ph.D. Defense Committee. Their highly insightful com- ments have helped me complete my Ph.D. degree and achieve a solid research path towards this thesis. My sincere and warm thanks go also to the entire Broadband Wireless Networking Laboratory family including all current and former members, for their constant support and unwavering friendship throughout my years in the lab. A special mention goes to Bige Unluturk and Shuai Nie for the amazing times we shared during the course of our graduate years. A special thanks also goes to all the people I worked with as part of my research iv projects. I would like to acknowledge the support of National Science Foundation through these projects, which made the completion of this thesis possible. I am also grateful to Dr. Evgeny Khorov for hosting me in Moscow during the Summer of 2019 and Dr. Nakjung Choi for hosting me at Nokia Bell Labs during the Summer of 2020, and for their invaluable contributions to my growth as a researcher. I would also like to thank all my friends and roommates through the years. They have been a integral part of this journey and I will forever cherish their support. And finally, last but by no means least, I can never find enough words to express my gratitude to my family, who have been my rock through this journey, especially my parents Vidyut and Kavita, my uncle Kowshik, and my aunt Hema. This achievement would have not been possible without their love, support, and encouragement. v TABLE OF CONTENTS Acknowledgments................................... iv List of Tables...................................... xiii List of Figures..................................... xiv Summary........................................ xviii Chapter 1: Introduction................................ 1 1.1 Key Themes and Research Objectives .................... 3 1.1.1 Flexible Network Architectures for 5G and Beyond Cellular Systems4 1.1.2 The Internet of Space Things with CubeSats............. 6 1.2 Organization of the Thesis .......................... 9 Chapter 2: Previous Work.............................. 10 2.1 Software-Defined Mobile Network Architectures .............. 10 2.2 CubeSat-Based IoT and Broadband Services................. 14 Chapter 3: ARBAT: A Flexible Network Architecture for Modern Cellular Sys- tems.................................... 18 3.1 Motivation................................... 18 3.2 System Architecture Overview........................ 21 vi 3.2.1 System Domains ........................... 21 3.2.2 Stakeholders ............................. 23 3.3 Infrastructure Plane.............................. 24 3.3.1 The Universal Network Device.................... 25 3.3.2 Transport Links............................ 27 3.3.3 Resource Virtualization and Abstraction............... 28 3.3.4 Unified Cellular Network....................... 29 3.4 Data Plane................................... 30 3.5 Control Plane ................................. 33 3.5.1 xNode................................. 34 3.5.2 Multi-Slice Radio Resource Management .............. 36 3.6 Management and Orchestration........................ 42 3.6.1 Network Function Virtualization Orchestrator............ 42 3.6.2 Virtual Network Function Manager.................. 43 3.6.3 Virtualized Infrastructure Manager.................. 43 3.6.4 Network Catalog ........................... 44 3.6.5 Network Status Database....................... 44 3.6.6 ServiceBRIDGE ........................... 45 3.7 Qualitative Evaluation............................. 47 3.8 Highlights................................... 50 Chapter 4: Radio Access Network Design with Software-Defined Mobility Man- agement.................................. 52 4.1 Motivation................................... 52 vii 4.2 Related Work ................................. 54 4.3 System Model................................. 57 4.3.1 Network Architecture......................... 57 4.3.2 Software-Defined Mobility Management Framework . 58 4.4 Problem Formulation............................. 64 4.5 Performance Evaluation............................ 76 4.6 Highlights................................... 79 Chapter 5: Adaptive Containerization for Microservices-Based Core Networks. 80 5.1 Motivation and Related Work......................... 80 5.2 System Model................................. 84 5.2.1 Preliminaries ............................. 84 5.2.2 Problem Formulation......................... 85 5.2.3 System Operation........................... 88 5.3 Performance Evaluation............................ 90 5.4 Highlights................................... 93 Chapter 6: End-to-End System Design for the Internet of Space Things..... 94 6.1 Motivation................................... 94 6.2 Application Scenarios............................. 98 6.2.1 Monitoring and Reconnaissance ................... 99 6.2.2 In-Space Backhaul ..........................100 6.2.3 Cyber-Physical Integration......................102 6.3 System Architecture Design..........................103 viii 6.3.1 Key Features .............................104 6.3.2 System Architecture Overview....................106 6.4 Infrastructure Layer..............................107 6.4.1 Access Network............................108 6.4.2 IoST Hubs...............................109 6.4.3 CubeSats ...............................110 6.4.4 Resource Virtualization........................110 6.5 Control and Management Layer .......................111 6.5.1 IoST Network Base..........................111 6.5.2 IoST Virtualization Manager.....................112 6.5.3 Slice Controller............................112 6.5.4 Network Orchestration and Operations Controller . 113 6.5.5 Access Network Controller......................114 6.5.6 Security Controller..........................115 6.6 Policy Layer..................................116 6.7 System Procedures ..............................116 6.7.1 Joint Optimal Physical-Link Layer Resource Allocation with vCSI . 117 6.7.2 Tackling Long delays and Temporal Variation in Network Topology Through Stateful Segment Routing..................118 6.7.3 Robust Connectivity Through Optimal IoST Hub Geolocations . 119 6.7.4 Synchronization of Geo-Distributed IoST Hubs . 120 6.7.5 Proactive Handovers Through GSL Outage Forecasting . 121 6.7.6 Lightweight Hardware Virtualization for CubeSats . 122 ix 6.7.7 Automated Device Provisioning Through ANC . 122 6.8 System Performance Evaluation .......................123 6.8.1 Single-Hop Link Metrics.......................124 6.8.2 Next-Hop Link Metrics........................126 6.8.3 Overall System Performance.....................127 6.9 Highlights...................................128 Chapter 7: Large-Scale Constellation Design for Ultra-Dense CubeSat Networks 130 7.1 Motivation...................................130 7.2 Related Work .................................134 7.2.1 State-of-the-Art Design