Michael Karrenbauer

Providing Physical Layer Security for Mission Critical Machine Type Communication

The design of wireless systems for Mission Critical Machine Type Communication (MC-MTC) is currently a hot research topic. Wireless systems are considered to provide numerous advantages over wired systems in industrial applications for example. However, due to the broadcast nature of the wireless channel, such systems are prone to a wide range of cyber attacks. These range from passive eavesdropping attacks to active attacks like data manipulation or masquerade attacks. Therefore it is necessary to provide reliable and efficient security mechanisms. One of the most important security issue in such a system is to ensure integrity as well as authenticity of exchanged messages over the air between communicating devices in order to prohibit active attacks. In the present work, an approach on how to achieve this goal in MC-MTC systems based on Physical Layer Security (PHYSEC), especially a new method based on keeping track of channel variations, will be presented and a proof-of-concept evaluation is given.

Physical Layer Authentication for Mission Critical Machine Type Communication Using Gaussian Mixture Model Based Clustering

The application of Mission Critical Machine Type Communication (MC-MTC) in wireless systems is currently a hot research topic. Wireless systems are considered to provide numerous advantages over wired systems in e.g. industrial applications such as closed loop control. However, due to the broadcast nature of the wireless channel, such systems are prone to a wide range of cyber attacks. These range from passive eavesdropping attacks to active attacks like data manipulation or masquerade attacks. Therefore it is necessary to provide reliable and efficient security mechanisms. Some of the most important security issues in such a system are to ensure integrity as well as authenticity of exchanged messages over the air between communicating devices. In the present work, an approach on how to achieve this goal in MC-MTC systems based on Physical Layer Security (PHYSEC) is presented. A new method that clusters channel estimates of different transmitters based on a Gaussian Mixture Model is applied for that purpose. Further, an experimental proof-of-concept evaluation is given and we compare the performance of our approach with a mean square error based detection method.

Radio Link Enabler for Context-Aware D2D Communication in Reuse Mode

Device-to-Device (D2D) communication is considered as one of the key technologies for the fifth generation wireless communication system (5G) due to certain benefits provided, e.g. traffic offload and low end-to-end latency. A D2D link can reuse resource of a cellular user for its own transmission, while mutual interference in between these two links is introduced. In this paper, we propose a smart radio resource management (RRM) algorithm which enables D2D communication to reuse cellular resource, by taking into account of context information. Besides, signaling schemes with high efficiency are also given in this work to enable the proposed RRM algorithm. Simulation results demonstrate the performance improvement of the proposed scheme in terms of the overall cell capacity.

Efficient Spectrum Sharing in Heterogeneous Wireless Environments

Abstract Today, spectrum is scarce because of the growing number of wireless devices and the steadily increasing demand for high data rates. Streaming and online gaming are a new kind of challenge for wireless networks in terms of delay and throughput. Systems like LTE enable high data-rates (100 MBit/s and above) combined with a low latency. Despite of all these new transmission technologies a major bottleneck is caused by the available spectrum. Furthermore this problem gets exacerbated by a static frequency assignment. To overcome this bottleneck new concepts for adaptive spectrum assignment with respect to load situation need to be developed. In this article we describe and evaluate an architecture which is able to handle different kinds of spectrum sharing techniques. Furthermore, our approach is able to deal with short time sharing (up to one minute). Therefore, we developed a Spectrum Management System (SMS) which is based on a hierarchical organized distributed hash table (DHT) architecture. Additionally, our system deploys databases for additional information like spectrum usage rules, incumbents or network coverage information (described by polygons). To enable the handling of time-critical spectrum data, we introduce a time synchronisation protocol named Lightweight Time Synchronisation (LT-Sync) which considers the system architecture and estimates transmission delays.