Over-The-Air (OTA) Measurement Method for MIMO-enabled Mobile Terminals

Over-The-Air (OTA) test methods for performance evaluation play an important role in the certification process of commercial User Equipment (UE) and for admission of UE to cellular networks. Novel OTA test methods and metrics are required for state-of-the-art mobile communication standards such as 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) due to the extensive use of Multiple Input – Multiple Output (MIMO) transmission techniques. The variety of different MIMO operating modes and the almost unlimited choice of possible multi-path channel conditions under which UE performance may be evaluated is not accounted for by established Single Input – Single Output (SISO) OTA performance metrics like Total Isotropic Sensitivity (TIS) and Total Radiated Power (TRP). As pointed out in this dissertation, meaningful metrics and cost effective, low complexity measurement methods can nevertheless be derived by focusing on characterization of the physical attributes of UE and by adopting statistical metrics. Starting from an overview of existing OTA measurement methods for SISO devices, extensions which are necessary to evaluate UE performance in the different MIMO operating modes which are foreseen in the 3GPP LTE standard are discussed. Relations between UE implementation attributes and the UE performance which is observed in different MIMO operating modes are derived using generic antenna and propagation models. Based on these models existing proposals for OTA test methods are reviewed. Their suitability and the relevance of different implementation aspects therein are discussed. The main result of this dissertation is a novel MIMO OTA test plan which focuses on the characterization of relevant UE attributes and meets the goals of low complexity and high reproducibility. Two complementary metrics and corresponding measurement procedures for evaluation of MIMO OTA performance are developed in order to address the diversity of possible propagation scenarios. The theoretical results are supported by extensive measurements using preliminary implementations of the proposed method. These include results from an international round-robin measurement campaign for High-Speed Packet Access (HSPA) devices and results from a variety of measurements on LTE devices which were performed at different test sites. Additional validation and investigation of specific aspects is addressed by simulation.Over-The-Air (OTA) Messverfahren für MIMO-fähige mobile Endgeräte Over-The-Air (OTA) Testverfahren für die Bewertung der Qualität von kommerziellen Endgeräten (User Equipment (UE)) sind von großer Bedeutung im Rahmen der Zertifizierung von UE und der Zulassung zu Mobilfunknetzwerken. Im Zusammenhang mit den aktuellen mobilen Kommunikationsstandards, wie etwa dem 3rd Generation Partnership Project (3GPP) Standard Long Term Evolution (LTE), sind, aufgrund der Verwendung von Multiple Input – Multiple Output (MIMO) Übertragungstechniken neuartige Metriken und Messverfahren erforderlich. Die Vielfalt der verschiedenen MIMO Betriebsarten und die fast unbegrenzte Auswahl möglicher Kanalbedingungen (Mehrwegeausbreitung), unter denen die Qualität von UE bewertet werden kann, wird von den etablierten Single Input – Single Output (SISO) OTA Metriken Total Isotropic Sensitivity (TIS) und Total Radiated Power (TRP) nicht abgedeckt. Wie in dieser Arbeit gezeigt wird, lassen sich durch Fokussierung auf die Charakterisierung der maßgeblichen physikalischen Eigenschaften des UE sowie Einführung statistischer Metriken dennoch aussagekräftige Metriken und kostengünstige Messmethoden geringer Komplexität gewinnen. Ausgehend von einem Überblick existierender OTA Testverfahren für SISO Endgeräte werden die Erweiterungen diskutiert, die notwendig sind, um die Qualität von Endgeräten unter den verschiedenen MIMO Betriebsarten, die der Standard 3GPP LTE vorsieht, bewerten zu können. Unter Verwendung generischer Modelle für Antennen und Ausbreitungsszenarien werden Beziehungen zwischen den Eigenschaften von UE und der in den verschiedenen MIMO Betriebsarten zu beobachtenden Emfangsqualität abgeleitet. Darauf aufbauend werden existierende Vorschläge für OTA Testverfahren untersucht. Deren Eignung und die Relevanz der verschiedener Aspekte in ihrer Implementierung werden diskutiert. Das wesentliche Ergebnis dieser Arbeit ist ein neuartiges MIMO OTA Testkonzept, bei dem die Charakterisierung der relevanten UE Eigenschaften im Mittelpunkt steht und welches den Anforderungen geringer Komplexität und hoher Reproduzierbarkeit genügt. Es werden zwei einander ergänzende Metriken definiert und die zugehörigen Testvorschriften vorgestellt, mit dem Ziel die Vielfalt der möglichen Übertragungszenarien abzudecken. Der theoretische Herleitungen werden durch umfangreiche Messungen mit vorläufigen Implementierungen des vorgeschlagenen Testkonzeptes unterstüzt. Dazu gehören Ergebnisse aus einer internationalen Round-Robin-Messkampagne für High-Speed Packet Access (HSPA)-Endgeräte und Ergebnisse aus zahlreichen Messungen an LTE Endgeräten, die in verschiedenen Laboren durchgeführt wurden. Eine Zusätzliche Validierung sowie die Untersuchung einiger spezifischer Aspekte erfolgt mit Hilfe von Simulationen

INDEMICS: An Interactive High-Performance Computing Framework for Data Intensive Epidemic Modeling

We describe the design and prototype implementation of Indemics (_Interactive; Epi_demic; _Simulation;)—a modeling environment utilizing high-performance computing technologies for supporting complex epidemic simulations. Indemics can support policy analysts and epidemiologists interested in planning and control of pandemics. Indemics goes beyond traditional epidemic simulations by providing a simple and powerful way to represent and analyze policy-based as well as individual-based adaptive interventions. Users can also stop the simulation at any point, assess the state of the simulated system, and add additional interventions. Indemics is available to end-users via a web-based interface. Detailed performance analysis shows that Indemics greatly enhances the capability and productivity of simulating complex intervention strategies with a marginal decrease in performance. We also demonstrate how Indemics was applied in some real case studies where complex interventions were implemented

Improvements on Uncertainty Quantification for Node Classification via Distance-Based Regularization

Deep neural networks have achieved significant success in the last decades, but they are not well-calibrated and often produce unreliable predictions. A large number of literature relies on uncertainty quantification to evaluate the reliability of a learning model, which is particularly important for applications of out-of-distribution (OOD) detection and misclassification detection. We are interested in uncertainty quantification for interdependent node-level classification. We start our analysis based on graph posterior networks (GPNs) that optimize the uncertainty cross-entropy (UCE)-based loss function. We describe the theoretical limitations of the widely-used UCE loss. To alleviate the identified drawbacks, we propose a distance-based regularization that encourages clustered OOD nodes to remain clustered in the latent space. We conduct extensive comparison experiments on eight standard datasets and demonstrate that the proposed regularization outperforms the state-of-the-art in both OOD detection and misclassification detection.Comment: Neurips 202

Blockchain-assisted Undisclosed IIoT Vulnerabilities Trusted Sharing Protection with Dynamic Token

With the large-scale deployment of industrial internet of things (IIoT) devices, the number of vulnerabilities that threaten IIoT security is also growing dramatically, including a mass of undisclosed IIoT vulnerabilities that lack mitigation measures. Coordination Vulnerabilities Disclosure (CVD) is one of the most popular vulnerabilities sharing solutions, in which some security workers (SWs) can develop undisclosed vulnerabilities patches together. However, CVD assumes that sharing participants (SWs) are all honest, and thus offering chances for dishonest SWs to leak undisclosed IIoT vulnerabilities. To combat such threats, we propose an Undisclosed IIoT Vulnerabilities Trusted Sharing Protection (UIV-TSP) scheme with dynamic token. In this article, a dynamic token is an implicit access credential for an SW to acquire an undisclosed vulnerability information, which is only held by the system and constantly updated as the SW access. Meanwhile, the latest updated token can be stealthily sneaked into the acquired information as the traceability token. Once the undisclosed vulnerability information leaves the SW host, the embedded self-destruct program will be automatically triggered to prevent leaks since the destination MAC address in the traceability token has changed. To quickly distinguish dishonest SWs, trust mechanism is adopted to evaluate the trust value of SWs. Moreover, we design a blockchain-assisted continuous logs storage method to achieve the tamper-proofing of dynamic token and the transparency of undisclosed IIoT vulnerabilities sharing. The simulation results indicate that our proposed scheme is resilient to suppress dishonest SWs and protect the IoT undisclosed vulnerabilities effectively.Comment: 10 pages,12 figure