Requirement-oriented information distribution in connected mobility scenarios

Die Zahl vernetzter Fahrzeuge wächst stetig. Während derzeit die meisten mobilen Onlinedienste in den Bereichen Infotainment und Navigation angesiedelt sind, ist zukünftig mit einer Ausdehnung in die Domäne der Fahrerassistenz zu rechnen. Da Fahrerassistenzsysteme mitunter aktiv in die Fahrzeugführung eingreifen, gelten hohe Anforderungen bezüglich der Qualität und Aktualität der Daten. Zu spät zugestellte bzw. fehlende Daten können zu Fehlfunktionen führen, die ein Sicherheitsrisiko für die Fahrzeuginsassen sowie andere Verkehrsteilnehmer darstellen. Die Vernetzung der Fahrzeuge über das Internet erfolgt derzeit ausschließlich über Mobilfunknetze. Mobilfunknetze zeichnen sich durch eine hohe geografische Abdeckung aus, allerdings unterliegt die Qualität des Datenkanals örtlichen Schwankungen, die sich negativ auf die Funktionsfähigkeit und Zuverlässigkeit der mobilen Dienste auswirken können. Ein Weg zur Steigerung der Funktionsfähigkeit und Zuverlässigkeit ist die Verwendung sogenannter Connectivity-Maps. Connectivity-Maps enthalten georeferenzierte Daten zu Eigenschaften des Mobilfunknetzes, die im Rahmen von Messfahrten gesammelt wurden. Dieses a priori Wissen kann verwendet werden, um die Übertragung von Daten proaktiv zu planen. Die Übertragungszeitpunkte können so gewählt werden, dass eine möglichst hohe Qualität des Mobilfunkkanals vorliegt. In diesem Fall ist die spektrale Effizienz hoch, so dass weniger wertvolle Ressourcen der Luftschnittstelle für die Datenübertragung benötigt werden. In dieser Arbeit wird ein Verfahren vorgestellt, das die Datenverteilung von einem zentralen Server zu den Fahrzeugen optimiert. Ziel der Optimierung ist es, die Sendereihenfolge der Datenobjekte so zu wählen, dass unter Berücksichtigung individueller spätester Zustellzeitpunkte eine möglichst hohe Ausnutzung der Luftschnittstelle erreicht wird. Die Arbeit fokussiert sich auf High Speed Downlink Packet Access (HSDPA) und verwendet als Maß für die Kanalqualität den sogenannten Channel Quality Indicator (CQI). Aus gemessenen CQI-Werten wird zunächst die CQI-Karte erstellt, die den ortsbezogenen Zugriff auf historische CQI-Daten erlaubt. Auf Basis dieser Daten werden Übertragungsdauer und Kanalausnutzung der Datenobjekte prädiziert. Anhand dieser Prädiktion kann eine optimale Sendereihenfolge ermittelt werden. Die umfangreiche Evaluation des Verfahrens erfolgt unter Verwendung einer im Kontext dieser Arbeit entwickelten Simulationsumgebung.The number of connected cars is growing continuously. While currently most mobile services reside in the areas of infotainment and navigation, an extension to the domain of driver assistance systems is to be expected. Systems such as hazard or construction site assists are supplied with new data in real time, map based assistance functions receive updates of the map data on a daily basis. As these systems may actively intervene in the driving process, high requirements concerning the quality and timeliness of the data have to be met. Delayed or missing data may cause malfunctions posing a safety risk to vehicles' passengers and other road users. At the moment cellular networks are used to connect vehicles to the internet. Cellular networks are characterized by a large geographical coverage, but the quality of the wireless data channel suffers from local fluctuations. These fluctuations of channel quality may have a bad impact on the functionality and reliability of the mobile services. A way to improve the functionality and reliability is to use so called connectivity maps. Connectivity maps offer georeferenced characteristics of the cellular network, which have been collected within measurement drives. This a priori knowledge can be used to plan the transmission of data from the internet to the vehicles proactively. The transmission times can be chosen to ensure a maximum channel quality resulting in a high spectral efficiency. With high spectral efficiency, less precious resources of the air interface are required to transmit a data object. This thesis offers a new concept to optimize the data distribution from a central server to vehicles. The objective of the optimization is to find a data objects' order, which maximizes the utilization of the air interface but considers individual deadlines. The work focusses on High Speed Downlink Packet Access (HSDPA) and uses the Channel Quality Indicator (CQI) to measure the channel quality. Initially a CQI-map is created using in field CQI measurements. This map provides location based access to historical CQI values. These values are used to predict transmission duration and channel utilization. Based on the predictions the optimal transmission order is calculated. An extensive evaluation is carried out using a simulation environment, which has been developed within this thesis

A Distributed Service Delivery Platform for Automotive Environments: Enhancing Communication Capabilities of an M2M Service Platform for Automotive Application

Full version: Access restricted permanently due to 3rd party copyright restrictions. Restriction set on 11.04.2018 by SE, Doctoral CollegeThe automotive domain is changing. On the way to more convenient, safe, and efficient vehicles, the role of electronic controllers and particularly software has increased significantly for many years, and vehicles have become software-intensive systems. Furthermore, vehicles are connected to the Internet to enable Advanced Driver Assistance Systems and enhanced In-Vehicle Infotainment functionalities. This widens the automotive software and system landscape beyond the physical vehicle boundaries to presently include as well external backend servers in the cloud. Moreover, the connectivity facilitates new kinds of distributed functionalities, making the vehicle a part of an Intelligent Transportation System (ITS) and thus an important example for a future Internet of Things (IoT). Manufacturers, however, are confronted with the challenging task of integrating these ever-increasing range of functionalities with heterogeneous or even contradictory requirements into a homogenous overall system. This requires new software platforms and architectural approaches. In this regard, the connectivity to fixed side backend systems not only introduces additional challenges, but also enables new approaches for addressing them. The vehicle-to-backend approaches currently emerging are dominated by proprietary solutions, which is in clear contradiction to the requirements of ITS scenarios which call for interoperability within the broad scope of vehicles and manufacturers. Therefore, this research aims at the development and propagation of a new concept of a universal distributed Automotive Service Delivery Platform (ASDP), as enabler for future automotive functionalities, not limited to ITS applications. Since Machine-to-Machine communication (M2M) is considered as a primary building block for the IoT, emergent standards such as the oneM2M service platform are selected as the initial architectural hypothesis for the realisation of an ASDP. Accordingly, this project describes a oneM2M-based ASDP as a reference configuration of the oneM2M service platform for automotive environments. In the research, the general applicability of the oneM2M service platform for the proposed ASDP is shown. However, the research also identifies shortcomings of the current oneM2M platform with respect to the capabilities needed for efficient communication and data exchange policies. It is pointed out that, for example, distributed traffic efficiency or vehicle maintenance functionalities are not efficiently treated by the standard. This may also have negative privacy impacts. Following this analysis, this research proposes novel enhancements to the oneM2M service platform, such as application-data-dependent criteria for data exchange and policy aggregation. The feasibility and advancements of the newly proposed approach are evaluated by means of proof-of-concept implementation and experiments with selected automotive scenarios. The results show the benefits of the proposed enhancements for a oneM2M-based ASDP, without neglecting to indicate their advantages for other domains of the oneM2M landscape where they could be applied as well