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Item type:Publication, Access status: with files , FlowEmu: an open-source flow-based network emulatorWhen analyzing the impact of a communication system on the Quality of Experience (QoE) of an interactive application, simulation and mathematical modeling typically require reimplementation or modeling of the application under test and only provide insights in terms of selected Key Performance Indicators (KPIs), which raises the need for network emulation. In this demo, we present FlowEmu, an opensource flow-based network emulator that allows the user to manipulate the underlying model and analyze various statistics in real-time via an easy-to-use Graphical User Interface (GUI), by using interactive game streaming as an example application.Publicationtype: Journal ArticleScopus© Citations 2 178 149 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Time- and frequency-domain dynamic spectrum access: learning cyclic medium access patterns in partially observable environmentsUpcoming communication systems increasingly often tackle the spectrum scarcity problem through the coexistence with legacy systems in the same frequency band. Cognitive Radio presents popular methods for Dynamic Spectrum Access (DSA) that enable coexistence. Historically, DSA meant a separation solely in the frequency domain, while in recent years it has been extended through the dimension of time, by employing Machine Learning to learn semi-deterministic and cyclic medium access patterns of the legacy system that are observed through channel sensing. When this pattern is learnable, then a new system can utilize a neural network and predict future medium accesses, thus steering its own medium access. We investigate this novel and more fine-grained version of DSA, propose a predictor and show its capability of reliably predicting future medium accesses of a legacy system in an aeronautical coexistence scenario. We extend the predictor to the case of partial observability, where only a narrowband receiver is available, s.t. observations are limited to a single sensed channel per time slot. In particular, we propose a custom loss function that is tailored to partially observable environments. In the spirit of Open Science, all implementation files are released under an open licensePublicationtype: Journal ArticleScopus© Citations 1 124 242 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Evaluation of multi-hop ad-hoc routing protocols in wireless seismic data acquisition(Technische Universität Berlin, 2021); ; ; Due to impediments associated with cable-based seismic survey, Wireless Seismic Data Acquisition (WSDA) has recently gained much attention from contractors, exploration companies, and researchers to layout enabling wireless technology and architecture for Wireless Geophone Networks (WGN) in seismic explorations. A potential approach is to employ multi-hop wireless ad-hoc communication. In this study, we propose a multi-hop WGN architecture consisting of several subnetworks to realize the expected network performance. We investigate the performance of proactive and reactive routing protocols to examine the optimal number of geophones that could be effectively supported within a subnetwork. The performance metrics used are packet delivery ratio (PDR) and average end-to-end delay.Publicationtype: Journal ArticleScopus© Citations 2 217 284 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , A novel approach to achieving end-to-end QoS for avionic applications(Technische Universität Berlin, 2021); ; ; Future Internet of Things (IoT) applications, such as connected industry 4.0, become more challenging with the strict Quality of Service (QoS) requirements, including reliability and delay guarantees. Several mechanisms in the communication stack to match the expected QoS are already discussed and specified at different layers, with the goal to make the communication more reliable. They focus on the layer-specific enhancements. For example, Time-Slotted Channel Hopping (TSCH) is a link layer mechanism to avoid narrowband interference. On the network layer, several multi-path routing schemes are proposed to distribute the traffic load or to have backup paths with the purpose of making data transmissions more robust to link failures. In addition to the layer-specific improvements, an integration of the cross-layer information can guarantee an end-to-end QoS for communication in dynamic environments. In this work we propose and evaluate a cross-layer framework for celldisjoint routing, which eliminates overlapping resource scheduling in both time and frequency. It enables the end-to-end QoS for wireless sensor networks under the IPv6 Over the TSCH Mode of IEEE 802.15.4 (6TiSCH). The proposed framework, called 6TiSCH stack with cross-layer information exchange (6TiSCH-CLX), is validated on a selected set of aviation industry applications using both simulations and analytical model.Publicationtype: Journal ArticleScopus© Citations 1 172 174