7. GI/ITG KuVS Fachgespräch Drahtlose Sensornetze

In dem vorliegenden Tagungsband sind die Beiträge des Fachgesprächs Drahtlose Sensornetze 2008 zusammengefasst. Ziel dieses Fachgesprächs ist es, Wissenschaftlerinnen und Wissenschaftler aus diesem Gebiet die Möglichkeit zu einem informellen Austausch zu geben – wobei immer auch Teilnehmer aus der Industrieforschung willkommen sind, die auch in diesem Jahr wieder teilnehmen.Das Fachgespräch ist eine betont informelle Veranstaltung der GI/ITG-Fachgruppe „Kommunikation und Verteilte Systeme“ (www.kuvs.de). Es ist ausdrücklich keine weitere Konferenz mit ihrem großen Overhead und der Anforderung, fertige und möglichst „wasserdichte“ Ergebnisse zu präsentieren, sondern es dient auch ganz explizit dazu, mit Neueinsteigern auf der Suche nach ihrem Thema zu diskutieren und herauszufinden, wo die Herausforderungen an die zukünftige Forschung überhaupt liegen.Das Fachgespräch Drahtlose Sensornetze 2008 findet in Berlin statt, in den Räumen der Freien Universität Berlin, aber in Kooperation mit der ScatterWeb GmbH. Auch dies ein Novum, es zeigt, dass das Fachgespräch doch deutlich mehr als nur ein nettes Beisammensein unter einem Motto ist.Für die Organisation des Rahmens und der Abendveranstaltung gebührt Dank den beiden Mitgliedern im Organisationskomitee, Kirsten Terfloth und Georg Wittenburg, aber auch Stefanie Bahe, welche die redaktionelle Betreuung des Tagungsbands übernommen hat, vielen anderen Mitgliedern der AG Technische Informatik der FU Berlin und natürlich auch ihrem Leiter, Prof. Jochen Schiller

A Cognitive Routing framework for Self-Organised Knowledge Defined Networks

This study investigates the applicability of machine learning methods to the routing protocols for achieving rapid convergence in self-organized knowledge-defined networks. The research explores the constituents of the Self-Organized Networking (SON) paradigm for 5G and beyond, aiming to design a routing protocol that complies with the SON requirements. Further, it also exploits a contemporary discipline called Knowledge-Defined Networking (KDN) to extend the routing capability by calculating the “Most Reliable” path than the shortest one. The research identifies the potential key areas and possible techniques to meet the objectives by surveying the state-of-the-art of the relevant fields, such as QoS aware routing, Hybrid SDN architectures, intelligent routing models, and service migration techniques. The design phase focuses primarily on the mathematical modelling of the routing problem and approaches the solution by optimizing at the structural level. The work contributes Stochastic Temporal Edge Normalization (STEN) technique which fuses link and node utilization for cost calculation; MRoute, a hybrid routing algorithm for SDN that leverages STEN to provide constant-time convergence; Most Reliable Route First (MRRF) that uses a Recurrent Neural Network (RNN) to approximate route-reliability as the metric of MRRF. Additionally, the research outcomes include a cross-platform SDN Integration framework (SDN-SIM) and a secure migration technique for containerized services in a Multi-access Edge Computing environment using Distributed Ledger Technology. The research work now eyes the development of 6G standards and its compliance with Industry-5.0 for enhancing the abilities of the present outcomes in the light of Deep Reinforcement Learning and Quantum Computing

Towards Massive Machine Type Communications in Ultra-Dense Cellular IoT Networks: Current Issues and Machine Learning-Assisted Solutions

The ever-increasing number of resource-constrained Machine-Type Communication (MTC) devices is leading to the critical challenge of fulfilling diverse communication requirements in dynamic and ultra-dense wireless environments. Among different application scenarios that the upcoming 5G and beyond cellular networks are expected to support, such as eMBB, mMTC and URLLC, mMTC brings the unique technical challenge of supporting a huge number of MTC devices, which is the main focus of this paper. The related challenges include QoS provisioning, handling highly dynamic and sporadic MTC traffic, huge signalling overhead and Radio Access Network (RAN) congestion. In this regard, this paper aims to identify and analyze the involved technical issues, to review recent advances, to highlight potential solutions and to propose new research directions. First, starting with an overview of mMTC features and QoS provisioning issues, we present the key enablers for mMTC in cellular networks. Along with the highlights on the inefficiency of the legacy Random Access (RA) procedure in the mMTC scenario, we then present the key features and channel access mechanisms in the emerging cellular IoT standards, namely, LTE-M and NB-IoT. Subsequently, we present a framework for the performance analysis of transmission scheduling with the QoS support along with the issues involved in short data packet transmission. Next, we provide a detailed overview of the existing and emerging solutions towards addressing RAN congestion problem, and then identify potential advantages, challenges and use cases for the applications of emerging Machine Learning (ML) techniques in ultra-dense cellular networks. Out of several ML techniques, we focus on the application of low-complexity Q-learning approach in the mMTC scenarios. Finally, we discuss some open research challenges and promising future research directions.Comment: 37 pages, 8 figures, 7 tables, submitted for a possible future publication in IEEE Communications Surveys and Tutorial

Energy efficient routing using fuzzy neural network in wireless sensor networks

In wireless sensor networks, energy is a precious resource that should be utilized wisely to improve its life. Uneven distribution of load over sensor devices is also the reason for the depletion of energy that can cause interruptions in network operations as well. For the next generation’s ubiquitous sensor networks, a single artificial intelligence methodology is not able to resolve the issue of energy and load. Therefore, this paper proposes an energy-efficient routing using a fuzzy neural network (ERFN) to minimize the energy consumption while fairly equalizing energy consumption among sensors thus as to prolong the lifetime of the WSN. The algorithm utilizes fuzzy logic and neural network concepts for the intelligent selection of cluster head (CH) that will precisely consume equal energy of the sensors. In this work, fuzzy rules, sets, and membership functions are developed to make decisions regarding next-hop selection based on the total residual energy, link quality, and forward progress towards the sink. The developed algorithm ERFN proofs its efficiency as compared to the state-of-the-art algorithms concerning the number of alive nodes, percentage of dead nodes, average energy decay, and standard deviation of residual energy

Privacy in the Smart City - Applications, Technologies, Challenges and Solutions

Many modern cities strive to integrate information technology into every aspect of city life to create so-called smart cities. Smart cities rely on a large number of application areas and technologies to realize complex interactions between citizens, third parties, and city departments. This overwhelming complexity is one reason why holistic privacy protection only rarely enters the picture. A lack of privacy can result in discrimination and social sorting, creating a fundamentally unequal society. To prevent this, we believe that a better understanding of smart cities and their privacy implications is needed. We therefore systematize the application areas, enabling technologies, privacy types, attackers and data sources for the attacks, giving structure to the fuzzy term “smart city”. Based on our taxonomies, we describe existing privacy-enhancing technologies, review the state of the art in real cities around the world, and discuss promising future research directions. Our survey can serve as a reference guide, contributing to the development of privacy-friendly smart cities

Analysis of the impact of wireless mobile devices in critical industrial applications

The main objective of the thesis is to study the impact of mobile nodes in industrial applications with strict reliability and time constraints in both centralized and decentralized topologies. Considering the harsh wireless channel conditions of industrial environments, that goal implies a considerable challenge. In order not to compromise the performance of the system, a deterministic Real-Time (RT) communication protocol is needed, along with a mechanism to deal with changes in the topology due to the movements of the wireless devices. The existing wireless standard technologies do not satisfy the requirements demanded by the most critical industrial applications such as Distributed Control Systems (DCS) and, thus, wired communication cannot be directly replaced by wireless solutions. Nevertheless, the adoption of wireless communications can be seen as an extension to the existing wired networks to create hybrid networks with mobility requirements. The design of a proper communication solution depends mainly on the choice of the Medium Access Control (MAC) protocol, which is responsible for controlling access to the medium and thereby plays a vital role in decreasing latency and packet errors. Furthermore, the changes in the topology due to the movement of the wireless devices must be managed correctly in order not to affect the performance of the entire network. In this doctoral thesis, a hybrid centralized architecture designed for industrial applications with strict requirements in terms of robustness, determinism and RT is proposed and evaluated. For that, a wireless RT MAC scheme based on the IEEE 802.11 physical layer is proposed along with a Real-Time Ethernet (RTE) MAC scheme. This hybrid system ensures seamless communication between both media. With the aim of including mobile devices in the proposed architecture, a soft-handover algorithm is designed and evaluated. This algorithm guarantees an uninterrupted communication during the handover process without the need for a second radio interface and with a reduced growth in network overhead. Finally, the impact of mobile nodes in a decentralized wireless topology is analysed. For that, the Self-Organizing Time Division Multiple Access (STDMA) protocol is evaluated to analyse its viability as an alternative to carrying out a handover in industrial applications without centralized systems.El objetivo principal de la tesis es estudiar el impacto de los nodos móviles en las aplicaciones inalámbricas industriales con requisitos estrictos de tiempo y robustez tanto para topologías centralizadas como descentralizadas. Este objetivo supone un gran desafío dadas las adversas condiciones del canal inalámbrico en los entornos industriales. Para no comprometer el rendimiento del sistema, es necesario un protocolo de comunicación determinista y con garantías de tiempo real, junto con un mecanismo para hacer frente a los cambios en la topología debido al movimiento de los dispositivos inalámbricos. Las tecnologías estándar inalámbricas existentes no satisfacen los requisitos exigidos por las aplicaciones industriales más críticas, como los Sistemas de Control Distribuido (DCS - Distributed Control Systems) y, por lo tanto, las comunicaciones cableadas no pueden ser reemplazadas directamente por soluciones inalámbricas. Sin embargo, la adopción de las comunicaciones inalámbricas puede verse como una extensión de las redes cableadas existentes con el objetivo de crear redes híbridas con requisitos de movilidad. El diseño de una solución de comunicación adecuada depende principalmente de la elección del protocolo de control de acceso al medio (MAC - Medium Access Control), el cual, desempeña un papel vital en la disminución de la latencia y del número de paquetes erróneos. Además, los cambios en la topología debidos al movimiento de los dispositivos inalámbricos deben gestionarse correctamente para que el rendimiento de toda la red no se vea afectado. En esta tesis doctoral se propone y se evalúa una arquitectura híbrida centralizada diseñada para aplicaciones industriales con requisitos estrictos de robustez, determinismo y tiempo real. Para ello, se propone un esquema MAC inalámbrico con garantías de tiempo real basado en la capa física IEEE 802.11 junto con un esquema MAC basado en Ethernet en tiempo real (RTE - Real-Time Ethernet). Este esquema híbrido garantiza una comunicación continua entre ambos medios de comunicación. Con el objetivo de incluir dispositivos móviles en la arquitectura propuesta, se propone y evalúa un algoritmo de soft-handover. Este algoritmo garantiza una comunicación ininterrumpida durante el proceso de handover sin la necesidad de una segunda interfaz de radio y con un aumento reducido de la sobrecarga de la red. Finalmente, se analiza el impacto de los nodos móviles en una topología inalámbrica descentralizada. Para ello, se evalúa el protocolo del estado del arte Self-Organizing Time Division Multiple Access (STDMA) con el objetivo de analizar su viabilidad como alternativa para realizar un handover en las aplicaciones industriales sin sistemas centralizados.Tesi honen helburu nagusia, nodo mugikorrek fidagarritasun eta denboraren aldetik baldintza ugari eskatzen duten aplikazio industrial zentralizatu eta deszentralizatuetan duten eragina aztertzea da. Eremu industrialetako haririk gabeko kanaletan ematen diren komunikazioetarako baldintza bereziki aurkakoak direla medio, helburu honek erronka handia sortzen du. Sarearen errendimendua arriskuan ez jartzeko, determinista eta denbora errealeko komunikazio protokolo bat beharrezkoa da, haririk gabeko nodoen mugimenduaren ondorioz topologiaren aldaketei aurre egiteko mekanismo batekin batera. Haririk gabeko teknologia estandarrek ez dute aplikazio industrial kritikoenek dituzten baldintzak betetzen eta, beraz, kable bidezko komunikazioak ezin dira haririk gabeko sistemekin ordezkatu. Hala ere, haririk gabeko komunikazioen erabilpena jadanik existitzen diren kable bidezko komunikazioen hedadura bezala kontsidera daiteke, mobilitate baldintzak dituzten sare hibridoak sortuz. Komunikazio sistemaren diseinu egokia Medium Access Control (MAC) protokoloaren hautaketa zuzenean oinarritzen da gehien bat, sarbidea kontrolatzeaz arduratzen baita, honela ezinbesteko papera izanik latentzian eta pakete erroreen murrizketan. Horretaz aparte, bai sare zentralizatu eta deszentralizatuen kasuan, haririk gabeko nodoen mugimenduek sortutako tipologia aldaketak azkar eta zuzen kudeatu behar dira sare osoko errendimenduak kalterik ez jasateko. Doktore tesi honetan, fidagarritasun zorrotz, determinismo eta denbora-errealeko baldintzak dituzten industria aplikazioetarako arkitektura hibrido zentralizatu bat proposatu eta ebaluatu da. Horretarako, IEEE 802.11 maila fisikoan oinarritutako haririk gabeko MAC eskema bat proposatu da, Real-Time Ethernet-en (RTE) oinarritutako MAC eskema batekin batera. Eskema hibrido honek bi komunikabideen artean etengabeko komunikazioa bermatzen du. Proposatutako arkitekturan nodo mugikorrak kontuan hartu ahal izateko, soft-handover algoritmo bat proposatu eta ebaluatu da. Algoritmo honek etenik gabeko komunikazioa bermatzen du handover prozesuan zehar bigarren irrati interfaze baten beharrik gabe eta sareko gainkarga oso gutxi handituz. Azkenik, nodo mugikorrek duten eragina haririk gabeko topologia deszentralizatuetan aztertu da. Horretako, bibliografiako Self-Organizing Time Division Multiple Access (STDMA) protokoloa ebaluatu da industrial aplikazioetako sistema zentralizatuen handover mekanismoaren alternatiba gisa

Department of Computer Science Activity 1998-2004

This report summarizes much of the research and teaching activity of the Department of Computer Science at Dartmouth College between late 1998 and late 2004. The material for this report was collected as part of the final report for NSF Institutional Infrastructure award EIA-9802068, which funded equipment and technical staff during that six-year period. This equipment and staff supported essentially all of the department\u27s research activity during that period