A Search Strategy of Level-Based Flooding for the Internet of Things

This paper deals with the query problem in the Internet of Things (IoT). Flooding is an important query strategy. However, original flooding is prone to cause heavy network loads. To address this problem, we propose a variant of flooding, called Level-Based Flooding (LBF). With LBF, the whole network is divided into several levels according to the distances (i.e., hops) between the sensor nodes and the sink node. The sink node knows the level information of each node. Query packets are broadcast in the network according to the levels of nodes. Upon receiving a query packet, sensor nodes decide how to process it according to the percentage of neighbors that have processed it. When the target node receives the query packet, it sends its data back to the sink node via random walk. We show by extensive simulations that the performance of LBF in terms of cost and latency is much better than that of original flooding, and LBF can be used in IoT of different scales

Cooperative Learning for Distributed In-Network Traffic Classification

Inspired by the concept of autonomic distributed/decentralized network management schemes, we consider the issue of information exchange among distributed network nodes to network performance and promote scalability for in-network monitoring. In this paper, we propose a cooperative  learning  algorithm  for  propagation and  synchronization of network information among autonomic distributed network nodes for online traffic classification. The results show that network nodes with sharing capability perform better with a higher average accuracy of 89.21% (sharing data) and 88.37% (sharing clusters) compared to 88.06% for nodes without cooperative learning capability. The overall performance indicates that cooperative learning is promising for distributed in-network traffic classification

Autonomous Drone Network: Non-Intrusive Control and Indoor Formation Positioning

The Teal Group estimated worldwide drone expenditure in 2013 to be $5.2 billion. Since then, worldwide drone expenditure has risen considerably, with the International Data Corporation (IDC) forecasting worldwide spending on drones to total$12.3 billion in 2019, with a compound annual growth rate (CAGR) forecast of 30.6% to 2022. As of 2019, Goldman Sachs report military applications account for 70% of the total spend with consumer applications accounting for 17%, and commercial/civil applications accounting for the remaining 13% where the latter are showing the fastest growth. Applications in construction, agriculture, offshore oil and gas, policing, journalism, border protection, mining and cinematography are predicted to see the greatest drone investment. As the demands increase, and particularly for applications that are time critical or that span large geographical areas, the single drone solution may be inadequate due to its limited energy and payload. A multiple drone solution, where the drones are networked and the drone’s position is established by GPS (global positioning system), is able to complete demanding applications more efficiently. In such systems however, the accuracy of GPS can be substantially compromised when deployed near tall buildings, trees, or bridges or if deployed indoors or underground. In this research, a drone position determination (DPD) algorithm, is proposed to overcome the shortcomings of GPS when satellite signals are compromised. An ad-hoc Wi-Fi network of autonomous quadcopter drones is constructed, as a platform to demonstrate the algorithm performance. To complement the DPD algorithm calculation, a method to estimate the distance flown, and also estimate the complete flightpath of a drone by considering the interaction of the angular velocities of a quadcopter’s four rotors (AVQR), is presented. The flight plan to examine the AVQR algorithm yields results enabling the distance flown to be calculated to an accuracy of 95%

Wide-Area Time-Synchronized Closed-Loop Control of Power Systems And Decentralized Active Distribution Networks

The rapidly expanding power system grid infrastructure and the need to reduce the occurrence of major blackouts and prevention or hardening of systems against cyber-attacks, have led to increased interest in the improved resilience of the electrical grid. Distributed and decentralized control have been widely applied to computer science research. However, for power system applications, the real-time application of decentralized and distributed control algorithms introduce several challenges. In this dissertation, new algorithms and methods for decentralized control, protection and energy management of Wide Area Monitoring, Protection and Control (WAMPAC) and the Active Distribution Network (ADN) are developed to improve the resiliency of the power system. To evaluate the findings of this dissertation, a laboratory-scale integrated Wide WAMPAC and ADN control platform was designed and implemented. The developed platform consists of phasor measurement units (PMU), intelligent electronic devices (IED) and programmable logic controllers (PLC). On top of the designed hardware control platform, a multi-agent cyber-physical interoperability viii framework was developed for real-time verification of the developed decentralized and distributed algorithms using local wireless and Internet-based cloud communication. A novel real-time multiagent system interoperability testbed was developed to enable utility independent private microgrids standardized interoperability framework and define behavioral models for expandability and plug-and-play operation. The state-of-theart power system multiagent framework is improved by providing specific attributes and a deliberative behavior modeling capability. The proposed multi-agent framework is validated in a laboratory based testbed involving developed intelligent electronic device prototypes and actual microgrid setups. Experimental results are demonstrated for both decentralized and distributed control approaches. A new adaptive real-time protection and remedial action scheme (RAS) method using agent-based distributed communication was developed for autonomous hybrid AC/DC microgrids to increase resiliency and continuous operability after fault conditions. Unlike the conventional consecutive time delay-based overcurrent protection schemes, the developed technique defines a selectivity mechanism considering the RAS of the microgrid after fault instant based on feeder characteristics and the location of the IEDs. The experimental results showed a significant improvement in terms of resiliency of microgrids through protection using agent-based distributed communication

Comunicação entre elementos da rede numa gestão autonómica

Mestrado em Engenharia Electrónica e TelecomunicaçõesCom o aumento da dimensão, complexidade e dinamismo das redes de próxima geração, os protocolos de gestão tradicionais tornar-se-ão ineficientes devido às suas características centralizadas e limitações em termos de escalabilidade. É neste ponto que surge a necessidade de criar diferentes soluções de gestão de rede que respondam a requisitos como a automatização da resposta às alterações nas condições do meio, a optimização de recursos, a adaptabilidade às mudanças de topologia, a escalabilidade e a eficiência de processos. Como resposta às necessidades apresentadas surge o paradigma de In- Network Management (INM) cuja ideia principal é inserir nas várias entidades que compõem a rede, capacidades e funcionalidades de forma a que estas se tornem autónomas e a gestão da rede deixe de depender de entidades agregadoras externas/servidores. Isto implica um nível elevado de automatização, sincronismo e actualização da informação entre os vários elementos, podendo facilmente conduzir a um forte aumento do overhead. É no contexto do paradigma de INM que a presente dissertação se insere, na qual são propostos vários mecanismos de interacção entre entidades, de modo a incluir processos de comunicação cooperativa. De modo sucinto, ao nível das redes com fios, é testado um protocolo de descoberta, baseado na estratégia Hide & Seek. Ao nível das redes sem fios, usando como base o protocolo 802.11 MAC, são propostos mecanismos de comunicação entre entidades e um critério de classificação baseado em relações sociais entre nós (métrica social). As soluções apresentadas são avaliadas segundo diferentes parâmetros, em cenários com e sem fios. Os cenários de redes com fios foram avaliados numa testbed virtual, ao nível do overhead de mensagens e do tempo de convergência da informação do protocolo de descoberta desenvolvido, tendo sido ainda elaborada uma análise comparativa com outros protocolos. Nos cenários de redes sem fios implementados no simulador NS-3, analisou-se o impacto ao nível de alguns parâmetros de nível MAC. É objectivo futuro a avaliação do impacto ao nível da camada IP.With the increasing size, complexity and dynamism of next generation networks, the traditional management protocols will become highly inefficient due to their centralizing characteristics and limitations in terms of scalability. This is the point where the need to create different network management solutions that answer to requirements such as automation of the response to changes in environmental conditions, resource optimization, adaptability to topology changes, scalability and efficiency. In response to the needs presented, the In-Network Management (INM) paradigm arises, whose main idea is to place capabilities and features into the various entities that comprise the network, so that they become autonomous and network management no longer rely on external servers. This implies a high level of automation, synchronization and update of the information among all elements, which can easily lead to a high increase in overhead. This Master's Thesis works in part of the architecture proposed by the INM paradigm, in the proposed mechanisms of interaction between entities in order to enable the overall process of cooperative communication. Briefly, in the wired networks, we propose a discovery protocol, based on the Hide & Seek strategy. In terms of wireless networks, using the 802.11 MAC protocol as base, we propose mechanisms for communication between entities and a social based classification criterion (social metric). The presented solutions are evaluated according to different parameters, in wired and wireless scenarios. In wired scenarios, the discovery protocol developed was evaluated in terms of messages overhead and convergence time on a virtual testbed, and it was also performed a comparative analysis with other protocols. The wireless scenario was implemented in the NS-3 simulator with an analysis of the impact on some MAC level parameters. It is also a future goal the evaluation of the impact on IP layer parameters