FlowEmu: An Open-Source Flow-Based Network Emulator

When 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 open-source 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

Time- and Frequency-Domain Dynamic Spectrum Access: Learning Cyclic Medium Access Patterns in Partially Observable Environments

Upcoming 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 license

A Novel Approach to Achieving End-to-End QoS for Avionic Applications

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 cell- disjoint 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

Evaluation of Multi-hop Ad-hoc Routing Protocols in Wireless Seismic Data Acquisition

Due to impediments associated with cable-based seismic survey, Wireless Seismic Data Acquisition (WSDA) has recently gained much attention fromcontractors, 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

A novel data dissemination model for organic data flows

The number of computing devices of the IoT are expected to grow exponentially. To address the communication needs of the IoT, research is being done to develop new networking architectures and to extend existing architectures. An area that lacks attention in these efforts is the emphasis on utilisation of omnipresent local data. There are a number of issues (e.g., underutilisation of local resources and dependence on cloud based data) that need to be addressed to exploit the benefits of utilising local data. We present a novel data dissemination model, called the Organic Data Dissemination (ODD) model to utilise the omni-present data around us, where devices deployed with the ODD model are able to operate even without the existence of networking infrastructure. The realisation of the ODD model requires innovations in many different area including the areas of opportunistic communications, naming of information, direct peer-to-peer communications and reinforcement learning. This paper focuses on highlighting the usage of the ODD model in real application scenarios and the details of the architectural components

Nominal planning of a LTE 700 PPDR network in Germany

In Germany, 2 x 8MHz spectrum was assigned to Public Protection and Disaster Release (PPDR) services in the 700MHz frequency band. Currently public authorities operate for blue light services a national TETRA network using approximately 4,700 base station sites. This technical report examines the site portfolio for a national PPDR LTE network in 700MHz based on planning parameter for a PPDR network in Spain as published in [1]. Furthermore, the resulting planning margins are analysed using a common methodology for the nominal site count planning. Both planning approaches show that the number of sites given by TETRA is sufficient for a high quality LTE-based PPDR network in Germany. The following chapter shows the assumptions taken for the network planning. In chapter 3, the planning approach in Spain is summarized and applied for the site layout in Germany. In chapter 4, a common method for the nominal planning is used. However, in this case this method was applied not for obtaining the number of required sites, but for calculating the power budget margins if using the existing number of sites. Chapter 5 summarises this technical study