Enabling connectivity for tactical networks in mountainous areas by aerial relays

The dimension of the Meiac as a diffuser of Latin American art has been key in Spain in the late twentieth century. The genesis of the museum, its cultural policy of debate and diffusion, and the creation of a Latin American collection, which until then did not exist in Spain, forced Spanish art criticism to look at and reconsider work from Latin America. At present the Meiac has developed the new technological platforms, as a new perspective of identity and common imaginaries between Spain and Latin America.La dimensión del Meiac como difusor del arte latinoamericano ha sido clave en España a finales del siglo XX. La génesis del museo, su política cultural de debate y difusión y la creación de una colección latinoamericana, hasta entonces inexistente en España, obligó a la crítica artística española a mirar y a reconsiderar la obra procedente de Latinoamérica. En la actualidad el Meiac ha desarrollado las nuevas plataformas tecnológicas, como una nueva perspectiva de identidad e imaginarios comunes entre España y América Latina

Enabling connectivity for tactical networks in mountainous areas by aerial relays

A general modeling framework for realistic performance evaluations of tactical mobile ad-hoc networks deployed in mountainous areas is presented. The framework is easily extensible, and can be eventually automated. It can be also used to generate data for other network simulators. The framework utilizes the freely downloadable high resolution 3D terrain data to define time dependent trajectories of network nodes. The node speeds and directions are linked to the terrain profile which extends the previously proposed mobility models. The path-loss analysis along the node trajectories revealed the need for aerial relays to enable full network connectivity at all times. The network consisting of 5 cluster heads and a single stationary relay is considered as a case study. The relay location and its antenna height are optimized to achieve the line-of-sight connectivity over the whole mission duration. The antenna radiation pattern at the relay is incorporated in the analysis. The resulting star network topology is used by the cluster heads to broadcast their packets to all other cluster heads. Several relaying schemes including the amplify-and-forward and the decode-and-forward relaying are studied together with the go-back-N retransmissions to achieve the reliable data transfer

CONCEPTUALIZATION AND ANALYSIS OF USING UNMANNED AERIAL VEHICLES AS COMMUNICATIONS RELAYS IN A GPS-DENIED ENVIRONMENT

Many armed forces are becoming network-centric and highly interconnected. This transformation, along with decentralized decision-making, has been enabled by technological advancements in the digital battlefield. As the battlefield evolves and missions require units to be mobile and support numerous tactical capabilities, the current concept of deploying static radio-relay nodes to extend the range of communication may no longer be suitable. Hence, this thesis aims to design an operational concept using unmanned aerial systems such as aerostats and tactical drones to provide beyond line-of-sight communication for tactical forces while overcoming the limitations in a GPS-denied environment. The proposed concept is divided into three phases to assess operational and communication system needs, given Federal Communications Commission regulations that set the maximum effective isotropic radiated power in the industrial, scientific, and medical band at 36 dBm. The maximum communication range between two nodes can be studied using the Friis propagation equation. In addition, Simulink software is used to study the effective application throughput with respect to distance. From the analysis, IEEE 802.11ax can provide a higher data throughput and support both 2.4 GHz and 5.0 GHz frequency bands. Using a simulated environment and operational scenario, the estimated number of aerial systems required to provide communication coverage for a 50 km by 50 km area is determined.Captain, Singapore ArmyApproved for public release. Distribution is unlimited

Dynamic mission planning for communication control in multiple unmanned aircraft teams

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 147-160).As autonomous technologies continue to progress, teams of multiple unmanned aerial vehicles will play an increasingly important role in civilian and military applications. A multi-UAV system relies on communications to operate. Failure to communicate remotely sensed mission data to the base may render the system ineffective, and the inability to exchange command and control messages can lead to system failures. This thesis presents a unique method to control communications through distributed mission planning to engage under-utilized UAVs to serve as communication relays and to ensure that the network supports mission tasks. The distributed algorithm uses task assignment information, including task location and proposed execution time, to predict the network topology and plan support using relays. By explicitly coupling task assignment and relay creation processes the team is able to optimize the use of agents to address the needs of dynamic complex missions. The framework is designed to consider realistic network communication dynamics including path loss, stochastic fading, and information routing. The planning strategy is shown to ensure agents support both data-rate and interconnectivity bit-error- rate requirements during task execution. In addition, a method is provided for UAVs to estimate the network performance during times of uncertainty, adjust their plans to acceptable levels of risk, and adapt the planning behavior to changes in the communication environment. The system performance is verified through multiple experiments conducted in simulation. Finally, the work developed is implemented in outdoor flight testing with a team of up to four UAVs to demonstrate real-time capability and robustness to imperfections in the environment. The results validate the proposed framework, but highlight some of the challenges these systems face when operating in outdoor uncontrolled environments.by Andrew N. Kopeikin.S.M

Analysis of resource control in nondeterministic mobile ad hoc network systems : an unmanned aerial vehicle example

This thesis utilized known information about a dynamic graph in which resource needy nodes act as relays for control information to a supplier node in order to characterize system performance and analyze the effects of change on the system. The connectivity, or information sharing, was based on distance and since every node moved around a defined space, the connectivity of the graph changed constantly. Several different controllers and scenarios are investigated in order to extract the uniqueness in each performance curve which created a better understanding of this near nondeterministic system. One such application for this dynamic system is the automation of Unmanned Aerial Vehicles (UAVs). This paper utilizes the UAV example in order to bring life, and motivate this research. Note that there are many other applications and problems with similar voids in understanding that this approach could be applied. The United States Department of Defense is increasingly utilizing Unmanned Aerial Vehicles (UAVs) to support current operations. As of August 2010, there were 207 Intelligence, Surveillance, and Reconnaissance (ISR) sorties flown per day to provide essential battlespace situational awareness for Operation Enduring Freedom and Operation Iraqi Freedom [1]. This paper proposes an implementation of an autonomous UAV network that assumes cutting edge technologies can be combined to provide infinite\u27 ISR over a given area. The particular dynamics of this problem are characterized using systems techniques while changes to the performance factors on the system are found using information about the root system.\u2

A Survey on UAV-enabled Edge Computing: Resource Management Perspective

Edge computing facilitates low-latency services at the network's edge by distributing computation, communication, and storage resources within the geographic proximity of mobile and Internet-of-Things (IoT) devices. The recent advancement in Unmanned Aerial Vehicles (UAVs) technologies has opened new opportunities for edge computing in military operations, disaster response, or remote areas where traditional terrestrial networks are limited or unavailable. In such environments, UAVs can be deployed as aerial edge servers or relays to facilitate edge computing services. This form of computing is also known as UAV-enabled Edge Computing (UEC), which offers several unique benefits such as mobility, line-of-sight, flexibility, computational capability, and cost-efficiency. However, the resources on UAVs, edge servers, and IoT devices are typically very limited in the context of UEC. Efficient resource management is, therefore, a critical research challenge in UEC. In this article, we present a survey on the existing research in UEC from the resource management perspective. We identify a conceptual architecture, different types of collaborations, wireless communication models, research directions, key techniques and performance indicators for resource management in UEC. We also present a taxonomy of resource management in UEC. Finally, we identify and discuss some open research challenges that can stimulate future research directions for resource management in UEC.Comment: 36 pages, Accepted to ACM CSU

Optimal and receding-horizon path planning algorithms for communications relay vehicles in complex environments

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2009.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (p. 97-100).This thesis presents new algorithms for path planning in a communications constrained environment for teams of unmanned vehicles. This problem involves a lead vehicle that must gather information from a set of locations and relay it back to its operator. In general, these locations and the lead vehicle's position are beyond line of-sight from the operator and non-stationary, which introduces several difficulties to the problem. The proposed solution is to use several additional unmanned vehicles to create a network linkage between the operator and the lead vehicle that can be used to relay information between the two endpoints. Because the operating environment is cluttered with obstacles that block both line-of-sight and vehicle movement, the paths of the vehicles must be carefully planned to meet all constraints. The core problem of interest that is addressed in this thesis is the path planning for these link vehicles. Two solutions are presented in this thesis. The first is a centralized approach based on a numerical solution of optimal control theory. This thesis presents an optimal control problem formulation that balances the competing objectives of minimizing overall mission time and minimizing energy expenditure. Also presented is a new modification of the Rapidly-Exploring Random Tree algorithm that makes it more efficient at finding paths that are applicable to the communications chaining problem. The second solution takes a distributed, receding-horizon approach, where each vehicle solves for its own path using a local optimization that helps the system as a whole achieve the global objective.(cont.) This solution is applicable to real-time use onboard a team of vehicles. To offset the loss of optimality from this approach, a new heuristic is developed for the linking vehicles. Finally, both solutions are demonstrated in simulation and in flight tests in MIT's RAVEN testbed. These simulations and flight tests demonstrate the performance of the two solution methods as well as their viability for use in real unmanned vehicle systems.by Karl Christian Kulling.S.M

Intelligent aerial store & foreword packet repeater

A communication framework capable of rapid deployment and adaptive wireless support was designed and implemented using an unmanned aerial vehicle equipped with a 900 MHz, frequency- hopping transceiver configured as a store and forward packet repeater. Users with or without line of sight propagation between one another can automatically connect through the packet repeater and employ the aerial platform for extended data transfer. The airborne vehicle accommodates dynamic re-positioning in response to varying radio link conditions, thus supporting communication between highly mobile and/or line of sight-obstructed users even as the network topology evolves. Using open source and custom written software applications, as well as specially modified radio firmware, a command and data-logging environment was designed to monitor, control and initialize radio network conditions and vehicle platforms in real time. Careful real world evaluation of the developed system has demonstrated a robust platform capable of improvement to a user\u27s communication performance

Low Intensity Conflict: Contemporary Approaches and Strategic Thinking

Low Intensity Conflict (LIC) is a significant feature of the contemporary world and it is a particular challenge to the armed forces of many states which are involved is such conflict, or are likely to become so. This thesis is not concerned with how such difficult conflict situations arise. Rather it is concerned with how, from the point of view of the state, they may be contained and ultimately brought to a satisfactory resolution. The work is thus concerned with the practicalities of ending LIC. More specifically, the purpose of this research is to establish a framework of doctrinal and military principles applicable to the prevention and resolution of LIC. The principles of this thesis are based in numerous historical examples of LIC and six in depth case studies. These distilled principles are analysed in two central chapters, and are then applied in two latter defence force chapters so as to ensure there practicality and resilience. Numerous defence academics and military practitioners have been consulted in the production of this thesis; their contribution has further reinforced the functionality of the principles examined in this research. The research illustrates the criticality of a holistic approach to LIC. The function of this approach is to guarantee the stability of the sovereign state, by unifying civil, police, intelligence and military services. The effectiveness of the military elements must also be ensured, as military force is central to the suppression of LIC. Consequently, the research makes strategic and operational prescriptions, so as to improve the capability of defence forces that are concerned with preventing or resolving LIC