A Heterogeneous Communications Network for Smart Grid by Using the Cost Functions

Smart Grids (SG) is an intelligent power grid in which the different SG node types with different communication requirements communicates different types of information with Control Stations (CS). Radio Access Technologies (RATs) due to its advantages are considered as the main access method to be used in order to have bidirectional data transferring between different node types and CS. Besides, spectrum is a rare source and its demand is increasing significantly. Elaborating a heterogeneous in order to fulfill different SG node types communication requirements effectively, is a challenging issue. To find a method to define desirability value of different RAT to support certain node types based on fitness degree between RAT communication characteristics and node type communication requirements is an appropriate solution. This method is implemented by using a comprehensive Cost Function (CF) including a communication CF (CCF) in combination with Energy CF (ECF). The Key Point Indicators which are used in the CCF are SG node type communication requirements. The existing trade of between Eb/N0 and spectral efficiency is considered as ECF. Based on the achieved CCF and ECF and their tradeoffs, SG node types are assigned to different RATs. The proposed assigning method is sensitive to the SG node types densities. The numerical results are achieved by using MATLAB simulation. The other different outcomes of the research output such as cognitive radio in SG and collectors effect number on data aggregation are discussed as well

Security in Distributed, Grid, Mobile, and Pervasive Computing

This book addresses the increasing demand to guarantee privacy, integrity, and availability of resources in networks and distributed systems. It first reviews security issues and challenges in content distribution networks, describes key agreement protocols based on the Diffie-Hellman key exchange and key management protocols for complex distributed systems like the Internet, and discusses securing design patterns for distributed systems. The next section focuses on security in mobile computing and wireless networks. After a section on grid computing security, the book presents an overview of security solutions for pervasive healthcare systems and surveys wireless sensor network security

Performance and applicability of candidate routing protocols for smart grid's wireless mesh neighbor-area networks

Neighbor-area network (NAN) is one of the most important segments of a smart grid communication network (SGCN) since it is responsible for information exchanges between utilities and a large number of smart meters (SMs) to enable various important smart grid (SG) applications. Greedy perimeter stateless routing (GPSR) and the routing protocol for low-power and lossy networks (RPL) have been considered for wireless mesh NANs. This thesis presents a study on performance and applicability of these two protocols in various NAN scenarios.Specifically, packet transmission reliability and delay of GPSR and RPL in an IEEE 802.11-based wireless mesh NAN are evaluated through extensive simulations. The effects of wireless channel characteristics, network offered load levels and cluster sizes are also investigated to assess feasibility of these two protocolswith respect to different SG application requirements. In addition to comparing the reliability and efficiency of GPSR and RPL, special attentions have been addressed to the system robustness in the presence ofnode failures. Node failures could hinder the network connectivity and degrade the reliability of the NAN segment of the SGCN. This thesis proposes a mechanism, namely proactive parent switching (PPS) that adaptively switches preferred parent nodes in order to help RPL quickly deflect network traffics from points offailures in the NAN scenario. Simulations with varying network availability and traffic load are carried out in order to understand the impact of node failures to the routing performance of GPSR and RPL with PPS and how the PPS can help RPL mitigate them.The extensive simulation results first reveal that RPL has higher transmission reliability and lower delays than GPSR in all the three considered scenarios, i.e., different channel conditions, traffic loads and network sizes. Moreover, under the consideration of multiple node failures, RPL with PPS outperforms both conventional RPL and GPSR in transmission reliability since it can efficiently reroute packets over multiple alternative paths. Consequently, the results from this thesis indicate that RPL with PPS is a suitable routing protocol for NAN communications. However, RPL may impose extra requirements relating to its routing tablemanagement and maintenance. Therefore, there is still room for improving these two protocols for specific SG applications.Le réseau de région voisine (NAN: neighbor-area network) est l'un des plus importants composants du réseau de communication du smart grid puisqu'il est responsable de l'échange d'information entre les utilitaires et un large nombre de compteurs intelligents pour réaliser divers applications du smart grid (SG). Les deux protocoles de routage, GPSR (greedy perimeter stateless routing) et RPL (routing protocol for low-power and lossy networks), ont ont été considérés pour les NANs maillés sans fil. Cette thèse présente une étude sur la comparaison des performances et des applications de ces deux protocoles dans différents scénarios de NAN. Particulièrement, la fiabilité de la transmission de paquet et le délai du GPSR et du RPL dans réseau maillés IEEE 802.11 sont évalués par des simulations étendues. Les effets des caractéristiques du canal sans fil, des niveaux de charges de trafic et de la taille des groupes sont aussi examinés pour évaluer la faisabilité de ces deux protocoles par rapport aux différentes applications du reseau SG.En plus de comparer la fiabilité et l'efficacité du GPSR et du RPL, une attention particulière est adressée à la robustesse des systèmes en présence de nœuds défaillants. Les nœuds défaillants peuvent gêner la connectivité du réseau et dégrader la fiabilité du NAN. Cette thèse propose un mécanisme, nommé changement de parent proactif (PPS : proactive parent switching), qui change au nœud parent approprié afin d'aider le RPL à détourner rapidement le trafic des points de défaillance dans le NAN. Des simulations en variant la disponibilité du réseau et la charge de de trafic sont performés afin de comprendre l'impacte des nœuds défaillants à la performance du routage du GPSR et du RPL avec le PPS, et comment le PPS peut aider le RPL à les éviter.Les résultats de simulation révèlent que le RPL possède une fiabilité de transmission plus haute et un délai plus court que le GPSR dans les trois scénarios considérés, c'est-à-dire, différentes conditions de canal, charges de trafic et tailles du réseau. De plus, sous la condition de plusieurs nœuds défaillants, le RPL avec le PPS dépasse le RPL et le GPSR conventionnels en termes de fiabilité de transmission puisqu'il peut réacheminer efficacement les paquets à travers plusieurs trajets alternatifs. Par conséquent, les résultats de cette thèse indiquent que le RPL avec le PPS est un protocole de routage approprié pour les communications NAN. Cependant, le RPL peut imposer un traitement additionnel pour la gérance et la maintenance de sa table de routage. Donc, ces deux protocoles peuvent être améliorés pour des applications spécifiques du SG

Recent Development of Hybrid Renewable Energy Systems

Abstract: The use of renewable energies continues to increase. However, the energy obtained from renewable resources is variable over time. The amount of energy produced from the renewable energy sources (RES) over time depends on the meteorological conditions of the region chosen, the season, the relief, etc. So, variable power and nonguaranteed energy produced by renewable sources implies intermittence of the grid. The key lies in supply sources integrated to a hybrid system (HS)