With the introduction of 5G, flexible network management through Software-Defined Networking will become available in cellular networks. As this has not been designed for safety-critical application such as autonomous driving or aeronautical applications, special care needs to be taken to use it in such contexts. In this work, different objective functions for optimization and their respective impact on performance characteristics such as link utilization and latency are investigated and compared. This allows to better understand the impact of resilient flow placement under constrained capacity and latency on network performance. Results show that for critical systems, objective functions relating to link capacity result in poorer network performance as latency and resilience are more limiting factors. While optimizations for maximum resilience increase network usage, with tight latency constraints they are comparable in performance with link capacity optimization, while providing more resilience against failures.

Authors: Cora Perner, Georg Carle

Authors: Marcel von Maltitz, Dominik Bitzer, Georg Carle

Authors: Fabien Geyer, Steffen Bondorf

Authors: Cora Perner, Holger Kinkelin, Georg Carle

Authors: Holger Kinkelin, Heiko Niedermayer, Marc-Oliver Müller, Georg Carle

The Internet of Things (IoT) is managed by soft- ware. This software interfaces our physical surroundings. For a successful deployment of the IoT, providing adequate service security is essential. However, with its distributed heterogeneous nature, and its different stakeholders in the development process, securing IoT services is challenging. In this work we how certificates can be used to give services an identity for authentication. We show how the mechanism can be used to securely add attributes to the service executable. To reflect the dynamic distributed nature of the IoT, we show how the securely added attributes can be changed at runtime and how security policies can be enforced even on distributed loosely coupled IoT nodes. Our solution is based on pinning X.509v3 certificates to the service executables, and autonomously managing short certificate lifetimes for ensuring the desired security policies within guaranteed time limits. Besides the feasibility of our approach we asses the resulting traffic of the renewals and the power consumption of this process.

Authors: Marc-Oliver Pahl, Lorenzo Donini

Authors: Marc-Oliver Pahl

Authors: Marc-Oliver Pahl, Stefan Liebald, Lars Wüstrich

The Internet of Things (IoT) consists of collaborating microservices (\muSs). Some services offer interfaces to manage entities, others implement orchestration logic, yet others interface users. Dynamic binding of services is fundamental to enable portability and adaptivity of \muSs to their local (service) context. The central challenge of service composition is service discovery. Service discovery has been investigated a lot in the past. However, the focus was on low ISO/ OSI layer technologies such as UPNP or Bonjour. Implementing the IoT as a Service-Oriented Architecture (SOA) of \muSs requires a significantly more feature rich discovery on the application layer. A major challenge here is that the IoT is more heterogeneous and dynamic than classic IT SOA systems. The IoT therefore requires a novel service discovery. We present a semantically rich yet simple to use IoT service discovery mechanism. It consists of distributed so called search providers that implement semantic directories, and a federation mechanism that allows mapping complex search queries to simple search provider modules. Our approach reflects the heterogeneity of managed entities, and the dynamic adaptivity required to reflect the continuous changes of IoT spaces. We evaluate our solution qualitatively with a user study and quantitatively via latency measurements.

Authors: Marc-Oliver Pahl, Stefan Liebald

Authors: Stephan M. Günther, Maurice Leclaire, Maximilian Riemensberger, Georg Carle, Wolfgang Utschick