Multi-Drone-Cell 3D Trajectory Planning and Resource Allocation for Drone-Assisted Radio Access Networks

Equipped with communication modules, drones can perform as drone-cells (DCs) that provide on-demand communication services to users in various scenarios, such as traffic monitoring, Internet of things (IoT) data collections, and temporal communication provisioning. As the aerial relay nodes between terrestrial users and base stations (BSs), DCs are leveraged to extend wireless connections for uncovered users of radio access networks (RAN), which forms the drone-assisted RAN (DA-RAN). In DA-RAN, the communication coverage, quality-of-service (QoS) performance and deployment flexibility can be improved due to the line-of-sight DC-to-ground (D2G) wireless links and the dynamic deployment capabilities of DCs. Considering the special mobility pattern, channel model, energy consumption, and other features of DCs, it is essential yet challenging to design the flying trajectories and resource allocation schemes for DA-RAN. In specific, given the emerging D2G communication models and dynamic deployment capability of DCs, new DC deployment strategies are required by DA-RAN. Moreover, to exploit the fully controlled mobility of DCs and promote the user fairness, the flying trajectories of DCs and the D2G communications must be jointly optimized. Further, to serve the high-mobility users (e.g. vehicular users) whose mobility patterns are hard to be modeled, both the trajectory planning and resource allocation schemes for DA-RAN should be re-designed to adapt to the variations of terrestrial traffic. To address the above challenges, in this thesis, we propose a DA-RAN architecture in which multiple DCs are leveraged to relay data between BSs and terrestrial users. Based on the theoretical analyses of the D2G communication, DC energy consumption, and DC mobility features, the deployment, trajectory planning and communication resource allocation of multiple DCs are jointly investigated for both quasi-static and high-mobility users. We first analyze the communication coverage, drone-to-BS (D2B) backhaul link quality, and optimal flying height of the DC according to the state-of-the-art drone-to-user (D2U) and D2B channel models. We then formulate the multi-DC three-dimensional (3D) deployment problem with the objective of maximizing the ratio of effectively covered users while guaranteeing D2B link qualities. To solve the problem, a per-drone iterated particle swarm optimization (DI-PSO) algorithm is proposed, which prevents the large particle searching space and the high violating probability of constraints existing in the pure PSO based algorithm. Simulations show that the DI-PSO algorithm can achieve higher coverage ratio with less complexity comparing to the pure PSO based algorithm. Secondly, to improve overall network performance and the fairness among edge and central users, we design 3D trajectories for multiple DCs in DA-RAN. The multi-DC 3D trajectory planning and scheduling is formulated as a mixed integer non-linear programming (MINLP) problem with the objective of maximizing the average D2U throughput. To address the non-convexity and NP-hardness of the MINLP problem due to the 3D trajectory, we first decouple the MINLP problem into multiple integer linear programming and quasi-convex sub-problems in which user association, D2U communication scheduling, horizontal trajectories and flying heights of DBSs are respectively optimized. Then, we design a multi-DC 3D trajectory planning and scheduling algorithm to solve the sub-problems iteratively based on the block coordinate descent (BCD) method. A k-means-based initial trajectory generation scheme and a search-based start slot scheduling scheme are also designed to improve network performance and control mutual interference between DCs, respectively. Compared with the static DBS deployment, the proposed trajectory planning scheme can achieve much lower average value and standard deviation of D2U pathloss, which indicate the improvements of network throughput and user fairness. Thirdly, considering the highly dynamic and uncertain environment composed by high-mobility users, we propose a hierarchical deep reinforcement learning (DRL) based multi-DC trajectory planning and resource allocation (HDRLTPRA) scheme for high-mobility users. The objective is to maximize the accumulative network throughput while satisfying user fairness, DC power consumption, and DC-to-ground link quality constraints. To address the high uncertainties of environment, we decouple the multi-DC TPRA problem into two hierarchical sub-problems, i.e., the higher-level global trajectory planning sub-problem and the lower-level local TPRA sub-problem. First, the global trajectory planning sub-problem is to address trajectory planning for multiple DCs in the RAN over a long time period. To solve the sub-problem, we propose a multi-agent DRL based global trajectory planning (MARL-GTP) algorithm in which the non-stationary state space caused by multi-DC environment is addressed by the multi-agent fingerprint technique. Second, based on the global trajectory planning results, the local TPRA (LTPRA) sub-problem is investigated independently for each DC to control the movement and transmit power allocation based on the real-time user traffic variations. A deep deterministic policy gradient based LTPRA (DDPG-LTPRA) algorithm is then proposed to solve the LTPRA sub-problem. With the two algorithms addressing both sub-problems at different decision granularities, the multi-DC TPRA problem can be resolved by the HDRLTPRA scheme. Simulation results show that 40% network throughput improvement can be achieved by the proposed HDRLTPRA scheme over the non-learning-based TPRA scheme. In summary, we have investigated the multi-DC 3D deployment, trajectory planning and communication resource allocation in DA-RAN considering different user mobility patterns in this thesis. The proposed schemes and theoretical results should provide useful guidelines for future research in DC trajectory planning, resource allocation, as well as the real deployment of DCs in complex environments with diversified users

Collaborative autonomy in heterogeneous multi-robot systems

As autonomous mobile robots become increasingly connected and widely deployed in different domains, managing multiple robots and their interaction is key to the future of ubiquitous autonomous systems. Indeed, robots are not individual entities anymore. Instead, many robots today are deployed as part of larger fleets or in teams. The benefits of multirobot collaboration, specially in heterogeneous groups, are multiple. Significantly higher degrees of situational awareness and understanding of their environment can be achieved when robots with different operational capabilities are deployed together. Examples of this include the Perseverance rover and the Ingenuity helicopter that NASA has deployed in Mars, or the highly heterogeneous robot teams that explored caves and other complex environments during the last DARPA Sub-T competition. This thesis delves into the wide topic of collaborative autonomy in multi-robot systems, encompassing some of the key elements required for achieving robust collaboration: solving collaborative decision-making problems; securing their operation, management and interaction; providing means for autonomous coordination in space and accurate global or relative state estimation; and achieving collaborative situational awareness through distributed perception and cooperative planning. The thesis covers novel formation control algorithms, and new ways to achieve accurate absolute or relative localization within multi-robot systems. It also explores the potential of distributed ledger technologies as an underlying framework to achieve collaborative decision-making in distributed robotic systems. Throughout the thesis, I introduce novel approaches to utilizing cryptographic elements and blockchain technology for securing the operation of autonomous robots, showing that sensor data and mission instructions can be validated in an end-to-end manner. I then shift the focus to localization and coordination, studying ultra-wideband (UWB) radios and their potential. I show how UWB-based ranging and localization can enable aerial robots to operate in GNSS-denied environments, with a study of the constraints and limitations. I also study the potential of UWB-based relative localization between aerial and ground robots for more accurate positioning in areas where GNSS signals degrade. In terms of coordination, I introduce two new algorithms for formation control that require zero to minimal communication, if enough degree of awareness of neighbor robots is available. These algorithms are validated in simulation and real-world experiments. The thesis concludes with the integration of a new approach to cooperative path planning algorithms and UWB-based relative localization for dense scene reconstruction using lidar and vision sensors in ground and aerial robots

Territorial governance and climate adaptation. Towards an environmental perspective of urban regeneration

The literature, the scientific and disciplinary debate and the growing awareness on the part of national and international bodies of the impact of climate change on the territory (European Green Deal, 2019, Horizon Europe 2021-2027) have highlighted, in recent years, the need for climate-proof policies, strategies, tools and actions as a goal to be achieved through the updating and innovation of spatial government tools, according to an integrated and inter-scalar approach for the construction of urban regeneration strategies in coherence with the objectives of the European Strategy on adaptation to climate change (EU, 2021) and the addresses of the 17 Sustainable Development Goals of the 2030 Agenda for Sustainable Development (UN, 2015) and the Climate Conference (COP26, 2021). This scenario is reflected in the most recent EU programming and policies and is, moreover, a transversal objective of the PNRR (Mission 5 Inclusion and Cohesion (Urban Regeneration and Social Housing), as well as of the PNR 2021/2027 (AT 2 Humanistic Culture, Creativity, Social Transformation, Inclusive Society in close correlation with AT 5 Climate and AT 6 Environment). In this context, the contribution presents some of the results of the research activities carried out by the authors that highlight, starting from the analysis of national and international planning experiences and best practices, the urgency of defining new perspectives and new theoretical-methodological and operational references for an innovative planning system, as a tool for a sustainable and resilient regeneration of contemporary cities and territories, at the supra-municipal, municipal and local scale, with significant impacts on mitigation and adaptation to the effects of climate change

Flowscapes:

Flowscapes explores infrastructure as a type of landscape and landscape as a type of infrastructure. The hybridization of the two concepts seeks to redefine infrastructure beyond its strictly utilitarian definition while allowing spatial design to gain operative force in territorial transformation processes. The publication provides perspectives on the subject from design-related disciplines such as architecture, urban design, urban planning, landscape architecture and civil engineering. The book builds upon the multidisciplinary colloquium on landscape infrastructures, that is part of the Flowscapes graduation design studio of Landscape Architecture at the TU Delft.  The authors explore concepts, methods and techniques for design-related research on landscape infrastructures. Their main objective is to engage environmental and societal issues by means of integrative and design-oriented approaches. Through focusing on interdisciplinary design-related research of landscape infrastructures they provide important clues for the development of spatial armatures that can guide urban and rural development and have cultural and civic significance. The geographical context of the papers covers Europe, Africa, Asia and Northern America. All contributions in the book are double blind reviewed by experts in the field

Flowscapes:

Flowscapes explores infrastructure as a type of landscape and landscape as a type of infrastructure. The hybridization of the two concepts seeks to redefine infrastructure beyond its strictly utilitarian definition while allowing spatial design to gain operative force in territorial transformation processes. The publication provides perspectives on the subject from design-related disciplines such as architecture, urban design, urban planning, landscape architecture and civil engineering. The book builds upon the multidisciplinary colloquium on landscape infrastructures, that is part of the Flowscapes graduation design studio of Landscape Architecture at the TU Delft.  The authors explore concepts, methods and techniques for design-related research on landscape infrastructures. Their main objective is to engage environmental and societal issues by means of integrative and design-oriented approaches. Through focusing on interdisciplinary design-related research of landscape infrastructures they provide important clues for the development of spatial armatures that can guide urban and rural development and have cultural and civic significance. The geographical context of the papers covers Europe, Africa, Asia and Northern America. All contributions in the book are double blind reviewed by experts in the field

Advanced Location-Based Technologies and Services

Since the publication of the first edition in 2004, advances in mobile devices, positioning sensors, WiFi fingerprinting, and wireless communications, among others, have paved the way for developing new and advanced location-based services (LBSs). This second edition provides up-to-date information on LBSs, including WiFi fingerprinting, mobile computing, geospatial clouds, geospatial data mining, location privacy, and location-based social networking. It also includes new chapters on application areas such as LBSs for public health, indoor navigation, and advertising. In addition, the chapter on remote sensing has been revised to address advancements

Begone, Euclid!: Leasing Custom and Zoning Provision Engaging Retail Consumer Tastes and Technologies in Thriving Urban Centers

Is urban center retailing in a death spiral? Competition for consumers with Internet vendors is afoot; winners and losers shall be anointed. The threats to physical retailing in an era of the “Internet of Goods” initially are described below. Adaptations by tenants, landlords, and stakeholders in urban centers will be required quickly, and new perspectives and partnerships, including those among local and regional governments, are instrumental if physical retail operations in municipal cores are to survive. The balance of this article describes these needs from the vantage point of each stakeholder; but this article argues that integrating information and communication technological infrastructure into retail leasing practices and land use planning and zoning strategies is inescapable for the maintenance of resilient town centers. Part II of this article describes the overwhelming impact of Internet consumerism upon physical retailing while Part III explains the physical milieu’s remaining but shrinking opportunities to remain competitive with the online consumer realm. Parts IV and V demonstrate how information and communication technologies, with innovative strategizing by retailers and their landlords, can be leveraged to incite lasting consumer interest in physical shopping environments within a community’s commercial nodes. Parts VI and VII articulate the municipal imperatives, including policies to implement robust technology infrastructure and capitalizing on ICT’s inherent “intelligence,” required to maintain commercial core competitiveness

Reflections Of Identity On Architecture In The Age Of Globalization

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2014Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2014Bu çalışmanın amacı, “kimlik”in dinamiklerini anlamak, kimliğin komplike yapısının, küreselleşme çağında dönüştüğü süreci analiz etmek ve kimliğin küreselleşme çağında, mimarlık üzerindeki etkilerini sorgulamaktır. Yüzyılın son çeyreğinde, küresel bilgi ağlarının etkisi ve küresel tüketim stratejileri ile “kimlik” tüm dünyada yeniden ortaya çıkan bir tartışma konusu olmuştur. Mimarlık da kimlik tartışmalarının bir parçası haline gelmiştir. Küresellik, dünyanın uzak köşelerinde, birbirine benzeyen ikonik ve yüksek yapıların ortaya çıkışına bağlı olarak “mimarlığın homojenleşmesi” kavramını getiren, küresel kimliğin güç ve prestijinin temsiline dayanan, baskın bir mimarlık dilini üretmiştir. Mimarlıktaki bu yeni durum, insanlar ve mimarlar tarafından çoğunlukla, “kimliğin kaybı” iddiası ile ilişkili tepkilerle karşılaşmıştır. Küresel çağda, mimarlık-kimlik ilişkisinin ana sorunsalını, mimari tasarımda bir yandan teknoloji, çoğulluk/melezlik gibi küresel ihtiyaçlara cevap verebilecek yeterlilikte olunması sağlanırken, bir yandan da kimliğin “süreklilik”, “aidiyet” ve “tanıdıklık” gibi hislere olan ihtiyacının karşılanması gerekliliği oluşturmaktadır. Katar/Doha, hızlı kentsel gelişimi ve kültürel kapitalizmin doğuşunu deneyimlemesi sebebiyle, küresel sahnede ortaya çıkmıştır. Bu nedenle, bu çalışmanın kapsamında, yüzyılın son çeyreğindeki küresel dönemde, Doha’daki mimari örneklerin, “süreklilik”, “aidiyet” ve “tanıdıklık” hislerini nasıl temsil ve ifade ettikleri de incelenmiştir.The aim of this study is to understand the “identity” with its dynamics, examining the process in which its complicated nature is transformed in global age and exploring the reflections of identity affecting architecture in the age of globalization. In the last quarter of the century, with the impact of global information networks and the global consumption strategies, the “identity” becomes an emerging subject of debates all around the world. Architecture also becomes part of the identity debates. Globalization generates the dominance of a global architectural language based on power and prestige of global identity that brings the concept of “homogenization of architecture” due to the emerging of similar iconic and high-rise stereotypes in distant corners of the world, which counters with reactions mostly dealing with the “loss of identity” claims. The main problematic of the architecture-identity relation in the global age comes from the necessity of fulfilling the identity’s need for sense of “continuity”, “belonging” and “familiarity” in architecture while being capable of engaging with the global requirements such as technology, multiplicity/hybridity. Qatar/Doha emerges on the global stage in the last quarter of the century, by experiencing a rapid urban development and rise of a new form of cultural capitalism. Consequently it is also analyzed in the scope of this study that how the architectural examples in Doha address the senses of “continuity”, “belonging” and “familiarity” during the global period in the last quarter of the century.Yüksek LisansM.Sc