Jammers for mobile cellular systems applied to unauthorized UAVs

This research aims to explore jamming on digital mobile systems, with an initial focus towards the 2G and Global System of Mobile Communications (GSM) technologies. The main goal is to develop a jammer with an efficiency and complexity greater than the existent ones, capable to better disrupt digital mobile systems. The study consists of an analysis of the different techniques of jamming, that can disrupt the mobile cellular system’s communication, through a series of simulations using the Software Defined Radio (SDR) and the GNU Radio ecosystem. The same techniques will then be studied and evaluated in real life scenarios in order to select which one is the best regarding spectral efficiency, energy and complexity. Finally, the jammer returning the best results will be the one chosen to contribute sustainably for the issue with flying drones on restrict areas, such as airports and residential zones, and thus, decrease the number of accidents which nowadays happen usually with this kind of aircrafts.Neste estudo será feita uma abordagem ao jamming em sistemas móveis digitais, dando um maior foco inicial à tecnologia 2G, Sistema Global para Comunicações Móveis (GSM). O objetivo principal será o desenvolvimento de um sinal jammer, diferente dos já existentes em termos de eficiência e complexidade, capaz de causar interferência em sistemas móveis celulares. Será feito então uma análise às diferentes técnicas de interferência de sinal, capazes de perturbar a comunicação em sistemas móveis celulares, através da realização de simulações a partir da tecnologia Software Defined Radio (SDR) nomeadamente, a plataforma GNU Radio. As mesmas técnicas também serão estudadas e avaliadas num cenário real, de forma a fazer-se a seleção da melhor em termos de eficiência espectral, energia e complexidade. Finalmente, a técnica de jamming que demonstrar melhores resultados, irá representar o jammer que poderá contribuir de forma sustentável para a problemática da circulação de drones em zonas restritas, como aeroportos e zonas residenciais, para a diminuição dos acidentes, atualmente registados, com este tipo de aeronaves

Evolution of High Throughput Satellite Systems: Vision, Requirements, and Key Technologies

High throughput satellites (HTS), with their digital payload technology, are expected to play a key role as enablers of the upcoming 6G networks. HTS are mainly designed to provide higher data rates and capacities. Fueled by technological advancements including beamforming, advanced modulation techniques, reconfigurable phased array technologies, and electronically steerable antennas, HTS have emerged as a fundamental component for future network generation. This paper offers a comprehensive state-of-the-art of HTS systems, with a focus on standardization, patents, channel multiple access techniques, routing, load balancing, and the role of software-defined networking (SDN). In addition, we provide a vision for next-satellite systems that we named as extremely-HTS (EHTS) toward autonomous satellites supported by the main requirements and key technologies expected for these systems. The EHTS system will be designed such that it maximizes spectrum reuse and data rates, and flexibly steers the capacity to satisfy user demand. We introduce a novel architecture for future regenerative payloads while summarizing the challenges imposed by this architecture

Mobile Ad hoc Networking: Imperatives and Challenges

Mobile ad hoc networks (MANETs) represent complex distributed systems that comprise wireless mobile nodes that can freely and dynamically self-organize into arbitrary and temporary, "ad-hoc" network topologies, allowing people and devices to seamlessly internetwork in areas with no pre-existing communication infrastructure, e.g., disaster recovery environments. Ad hoc networking concept is not a new one, having been around in various forms for over 20 years. Traditionally, tactical networks have been the only communication networking application that followed the ad hoc paradigm. Recently, the introduction of new technologies such as the Bluetooth, IEEE 802.11 and Hyperlan are helping enable eventual commercial MANET deployments outside the military domain. These recent evolutions have been generating a renewed and growing interest in the research and development of MANET. This paper attempts to provide a comprehensive overview of this dynamic field. It first explains the important role that mobile ad hoc networks play in the evolution of future wireless technologies. Then, it reviews the latest research activities in these areas, including a summary of MANET\u27s characteristics, capabilities, applications, and design constraints. The paper concludes by presenting a set of challenges and problems requiring further research in the future