Andreas Timm-Giel

Technische Universität Hamburg | TUHH · Institute of Communication Networks

Going wireless is one of the key industrial trends, which assists the emergence of new manufacturing and maintenance processes by reducing the complexity and cost of physical equipment. However, the adoption of Wireless Sensor Networks (WSNs) in production environments is limited due to the strict Quality of Service (QoS) requirements of industrial...

The OMNeT++ simulator is well-suited for the simulation of randomized user behavior in communication networks. However, there are scenarios, where such a random model is unsuited to evaluate a communication system, and this paper attempts to highlight such a case. Using this example of ad-hoc communication between aircraft mid-flight, a tutorial-st...

We present an operation management controller for low voltage (LV) grids that coordinates a multitude of distributed energy resources (DER) in real time to maximize the utilization of renewable energy production. It utilizes an LTE radio network that connects the DERs to the distribution system operator. In our approach, utility functions are assig...

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 em...

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...

Seismic data acquisition in oil and gas exploration employs a large-scale network of geophone sensors deployed in thousands across a survey field. A central control unit acquires and processes measured data from geophones to come up with an image of the earth’s subterranean structure to locate oil and gas traps. Conventional seismic acquisition sys...

Fifth-generation (5G) cellular networks enable many vehicular communication applications by providing wireless interfaces for the exchange of messages among vehicles [vehicle to vehicle (V2V)] and among vehicles and pedestrians, infrastructure components, and application servers [vehicle to everything (V2X)]. Platoon networked control systems to ma...

This paper aims to share the experiences during online teaching of two different project-based learning courses at Hamburg University of Technology (TUHH) during the COVID-19 (Corona) pandemic 2020. The success of project-based learning courses relies on how freely and openly students can discuss their task-oriented problems in small teams. The mos...

Modern processors with multi-cores and several power states make power modeling of servers challenging. This issue becomes more complex in virtualized environments, owing to the presence of hypervisors. Requests and instructions as processed at the guest level cannot be straightforwardly related to instructions processed at the host, and this relat...

Opportunistic networks have recently seen increasing interest in the networking community. They can serve a range of application scenarios, most of them being destination-less, i.e., without a-priori knowledge of who is the final destination of a message. In this paper, we explore the usage of data popularity for improving the efficiency of data fo...

Power management and load balancing in data centers are becoming critical with the growing size of the infrastructure. In front of an increasing number of cloud networks, virtual machines (VMs) and containers, smart management and control decisions are required, in order to instantiate or mobilize these virtual components. As regards reducing power...

Today Wireless Sensor Networks (WSNs) can be found in many application areas, e.g. they are used in smart home systems or in industrial settings in order to monitor and control machinery. The latter usually requires a guaranteed performance of the network. This mainly addresses the real-time capability of the network, i.e. knowledge of possible del...

The Limited Relative Error algorithm is an alternative statistical method for data evaluation. Through online result analysis it continuously requests more samples until it deems the evaluation confident enough. With this it allows researchers to hand over the control of simulation time to the algorithm, and through a-priori configuration the targe...

At the Hamburg University of Technology, Germany, the modelling of communication networks using the OMNeT++ simulator and the INET framework is taught for Master students. Teaching the concepts of simulation and modelling while letting the students obtain a hands-on experience during a 14-week (4h/week) period (single semester) is a challenging tas...

Still today, aircraft disappear and crash without communicating their last position. Looking into details, satellite communications currently seems to be the only reliable way to connect and send data on long-distance flights. However, geostationary satellite systems suffer from high propagation delays making Forward Error Correction (FEC) schemes...

This paper focuses on modeling the charateristics of opportunistic networks (OppNets). The motivation of this work is to develop a model which is closer to the reality to represent the data dissemination in OppNets. This paper shows our preliminary results validating our model in OppNets scenarios which give an opportunity to exchange data among a...

Opportunistic networks (OppNets) are focused to exploit direct, localised communications which occur in a peer-to-peer manner mostly based on people's movements and their contact durations. Therefore, the use of realistic mobility models is critical to evaluate the data dissemination in OppNets. One of the mobility models that is available in OMNeT...

M2M communication offers ubiquitous applications and is one of the leading facilitators of the Internet of Things paradigm. Unlike human-tohuman communication, distinct features of M2M traffic necessitates specialized and interoperable communication technologies. However, most existing solutions offering wired or wireless connectivity have limitati...

Die Digitalisierung der Gesellschaft und Industrie schreitet unaufhörlich voran, und die Bedeutung des Zugangs zu uneingeschränkter mobiler Vernetzung für unser gesellschaftliches und berufliches Leben nimmt somit ebenfalls stetig zu. Mit der Entwicklung der 5G Mobilfunkgeneration, aber auch echtzeitfähiger lokaler Funknetze werden in Zukunft digit...

Decentralised electric power generation using renewable energy sources are becoming increasingly popular. As a consequence, decentralised electrical energy sources such as photovoltaic (PV) are connected to the low voltage (LV) power grids. This raises the requirement of dedicated and coordinated control of loads and power generation to realize int...

Communication over geostationary satellite links is improved by introducing end-to-end Forward Error Correction (FEC) and simultaneous transmissions over two links (channel bundling). The main objective of this work is to investigate to which degree the goodput and the reliability can be enhanced using the mentioned techniques. The performances of...

This book constitutes the refereed post-conference proceedings of the 8th International Conference on Mobile Networks and Management, MONAMI 2016, held in Abu Dhabi, United Arab Emirates, in October 2016. The 14 revised full papers were carefully reviewed and selected from 18 submissions. The papers are organized thematically in four parts, startin...

All over the world, road congestion is among the most prevalent transport challenges usually in urban environments which not only increases fuel consumption and emission of harmful gases, but also causes stress for the drivers. Intelligent Transportation System (ITS) enables a better use of the infrastructure by connecting vehicles to other vehicle...

Machine-to-Machine (M2M) communication is an emerging technology which offers various ubiquitous services and is one of the main enablers of the Internet-of-Things (IoT) paradigm. Nevertheless, the notion of cellular-M2M communication is emerging due to the wide range, high reliability, increased capacity and decreased costs of future mobile networ...

Long term evolution-advanced standardized as Release 10 by the 3rd generation partnership project is a packet-based 4G mobile radio system. Its capability to support a large number of voice calls through Voice over IP (VoIP) is of specific interest. Due to limited control channel capacity semi-persistent scheduling is used to periodically reserve r...

Machine-to-machine (M2M) communication is becoming an increasingly essential part of mobile traffic and thus also a major focus of the latest 4G and upcoming 5G mobile networks. M2M communication offers various ubiquitous services and is one of the main enablers of the Internet-of-things (IoTs) vision. Nevertheless, the concept of mobile M2M commun...

Determining the amount of air traffic in an area can help to identify the traffic demands of current and future airborne communication systems. Many mobility models for pedestrians and road vehicles exist, but hardly any for aircraft. Aircraft traces for three exemplary scenarios are analyzed to derive such a model with regard to traffic demand in...

Machine-to-machine (M2M) communication is becoming an increasingly important part of mobile traffic and thus also a topic of major interest for mobile communication research and telecommunication standardization bodies. M2M communication offers various ubiquitous services and is one of the main enablers of the vision inspired by the Internet of Thi...

Testbeds play a crucial role in evaluating novel protocols, algorithms, and applications in controlled, but realistic environments. These testbeds are mainly used by researchers to realize diverse application environments, which are not realistic to be achieved in simulated environments (e.g., lossy channels in Wireless Sensor Networks (WSN)). Most...

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...

Machine-to-Machine (M2M) communication is the communication between two or more devices which communicate with each other autonomously. The concept of mobile M2M communication has emerged due to the wide range, coverage provisioning and decreasing costs of future mobile networks. Consequently, M2M traffic poses significant challenges to mobile netw...

Network Virtualization is a key component of the Future Internet, providing the dynamic support of different networks with different paradigms and mechanisms in the same physical infrastructure. A major challenge in the dynamic provision of virtual networks is the embedding approach taking energy efficiency into account, while not affecting the ove...

Inter-cell interference mitigation in LTE networks is important to improve the system throughput. Upcoming Cloud Radio Access Networks (C-RANs) allow controlling multiple cells at a single location enabling novel inter-cell coordination algorithms. Coordinated recourse allocation can be used to achieve optimal spectral efficiency through reduced in...

Device-to-Device communication is discussed for future mobile communication systems. In this work, an upper bound capacity limit is determined for a mobile communication system consisting of Device-to-Device and cellular users is determined. Therefore, we formulate the problem as a linear program and solve it optimally. The potential of Device-to-D...

This book constitutes the post-proceedings of the 7th International Conference on Mobile Networks and Management, MONAMI 2015, held in Santander, Spain, in September 2015. The 16 full papers were carefully reviewed and selected from 24 submissions. In addition there appears one short and 5 invited papers. These are organized thematically in five pa...

This book constitutes the post-proceedings of the 6th International ICST Conference on Mobile Networks and Management, MONAMI 2014, held in Würzburg, Germany, in September 2014. The 22 revised full papers presented were carefully reviewed and selected from 30 submissions. In addition, MONAMI 2014 hosted a workshop on enhanced living environments wh...

The rapid growth in mobile traffic and broadband wireless connections, together with the advent of the Internet-of-Things call for novel mobile and wireless network management techniques, able to cope with an increasing number of challenges. Individual techniques can no longer be considered in isolation, but there must be a clear cooperation and cr...

Long term evolution (LTE) uses orthogonal frequency division multiple access (OFDMA) and single carrier frequency division multiple access (SC-FDMA) as the downlink and uplink transmission schemes respectively. The Quality of Service (QoS) provision to users is one of the key objectives of the wireless network operators. This paper analyses an upli...

Planning a communication network is a very challenging task, because network traffic is not constant but fluctuates heavily. Overestimating the traffic volume leads to an expensive solution, while underestimating it results in a poor Quality of Service (QoS). In this paper, we propose a new approach to solve the network planning problem under stoch...

Today's networking hardware (e.g. switches, routers) is typically running 24/7, regardless of the traffic volume. This is because in current networks, the controlling and data forwarding functions are embedded in the same devices, and all L2/L3 network protocols are designed to work in a distributed manner. Therefore, network devices must be switch...

Optimum utilisation of the transport links in the access networks as well as satisfaction of the end-user service quality (Quality of Experience - QoE) is important for mobile operators. The necessary prerequisites for proper dimensioning (capacity planning) of the access network are careful modeling of the arrival traffic characteristics and prope...

The current Internet architecture was designed more than 30 years ago for a very different set of services than those used today. Several new architectures have been proposed for a Future Internet to better meet today's and future requirements. Content Centric Networking (CCN) is a prominent Information Centric Networking (ICN) architecture which g...

As a cutting edge technology, Machine to Machine (M2M) communications are gaining ground for managing and controlling M2M devices. Since these objects have intelligence, communication capabilities and ability to work with their environment, they are ...

Christoph Goertz berät als Senior Consultant bei Detecon International GmbH weltweit Mobilfunkbetreiber im Bereich LTE, Voice over LTE und Virtualisierung. In seiner Zeit am Institut für Kommunikationsnetze ComNets an der RWTH Aachen hat er im Rahmen eines Forschungsprojekts an Methoden zur Koexistenz bei 4G OFDMA Systemen und deren Bewertungen gea...

Wireless sensors have been studied over recent years for different promising applications with high value for individuals and society. A good example are wireless sensor networks for patients allowing for better and more efficient monitoring of patients in hospitals or even early discharge form hospital and monitoring at home. These visions have ha...

Network Virtualization is claimed to be a key component of the Future Internet, providing the dynamic support of different networks with different paradigms and mechanisms in the same physical infrastructure. A major challenge in the dynamic provision of virtual networks is the efficient embedding of virtual resources into physical ones. Since this...

User mobility can cause severe degradation of QoS, which can be counteracted by performing handovers at the right moment. However, to perform a robust handover is a challenging task. In this paper, we study the handover problem for mobile wireless networks in the of?ce environment, where the users? mobility is predictable. We propose a new mechanis...

LTE-Advanced (LTE-A) standardized as Release 10 by the 3rd Generation Partnership Project (3GPP) is a packet-based 4G mobile radio system. Of specific interest is its capability to support a large number of voice calls through Voice over IP (VoIP) calls. Radio resource management for VoIP calls is challenging. Control channel limitations prevent th...