The demand for ubiquitous networks has pushed the designs of networks all the way. The requirement for access point to be integrated into IEEE 802.3 standard and other networks has always been a sore point in the limitation of wireless coverage of IEEE 802.11 standard networks. Wireless Mesh Network (WMN) is expected to be the future of the next generation wireless network. It is experiencing a fast growing development due to its attractive features which includes high reliable connectivity, easy deployment, self healing, self configuring, flexible network expansion etc. Hence the mobility of the WMN nodes has been of paramount importance, which would make it independent of wired infrastructure and flexible interoperability with various networks and devices. The requirements like mobility, transparency etc. have led to the amendment of the WMN standard by the Institute of Electronics and Electrical Engineering (IEEE) 802.11 Working Group (WG), Task Group (TG) “S. The IEEE 802.11s standard tackles these issues by its operation on layer 2 of Open Systems Interconnection (OSI) reference model and creates a transparent IEEE 802 broadcast domain that supports any higher layer protocol. In our work we give the evaluation of the upcoming IEEE 802.11s standard based on its features some of which include routing at layer 2 and medium access control to enable its design and implementation in the existing mesh frame work of Communication Research Labs (CRL) using the proposed IEEE 802.11s routing protocols with focus on RA-OLSR and HWMP. We concentrate on how to integrate these features into the existing CRL’s C-CORE which runs other layer 3 routing protocols and complex functions as Application Programming Interface (API) modules. The implementation of the IEEE 802.11s standard creates major challenges as we have to create a roadmap on integrating the new wireless kernel interfaces like the nl80211, cfg80211 and the Wireless Extension (Wext) into the CRL’s C-CORE framework for communication between user space and kernel space, especially taking into consideration of the existing HAL and madwifi wireless drivers of the CRL’s framework. To support the evaluation of the features like the layer 2 routing and the modified MAC performance, we compare results of the CRL’s real time mesh network test with our simulation result of the IEEE 802.11s standard using the Qualnet 4.5 simulator with focus on the basic network parameters like delay, jitter and throughput. The comparison shows that the CRL’s network has higher throughput running its existing layer 3 protocols. The analysis also proves that the 802.11s is flexible, scalable and efficient in delivering multi hop capabilities to clients that cannot afford the deployment time or the cost for wired networks that use access points. With the complete integration, of the 802.11s standard specifications the CRL’s C-CORE framework can be much more capable of supporting more diverse network scenario deployments. / +46-736318897

Finding an optimal solution to the problem of fast and efficient provisioning of reliable connections and failure recovery in future intelligent optical networks is an ongoing challenge. In this dissertation, we investigate and compare the performance of an adapted shared-path protection algorithm with a more conventional approach; both designed for survivable optical Wavelength Division Multiplexing (WDM) mesh networks. The effect of different classes of service on performance is also investigated. Dedicated path protection is a proactive scheme which reserves spare resources to combat single link failures. Conventional Shared-path Protection (CSP) is desirable due to the efficient utilization of resources which results from the sharing of backup paths. Availability is an important performance assessment factor which measures the probability that a connection is in an operational state at some point in time. It is the instantaneous counterpart of reliability. Therefore, connections that do not meet their availability requirements are considered to be unreliable. Reliability Aware Shared-path Protection (RASP) adopts the advantages of CSP by provisioning reliable connections efficiently, but provides protection for unreliable connections only. With the use of a link disjoint parameter, RASP also permits the routing of partial link disjoint backup paths. A simulation study, which evaluates four performance parameters, is undertaken using a South African mesh network. The parameters that are investigated are: 1. Blocking Probability (BP), which considers the percentage of connection requests that are blocked, 2. Backup Success Ratio (BSR), which considers the number of connections that are successfully provisioned with a backup protection path, 3. Backup Primary Resource Ratio (BPR), which considers the ratio of resources utilized to cater for working traffic to the resources reserved for protection paths and lastly 4. Reliability Satisfaction Ratio (RSR), which evaluates the ratio of provisioned connections that meet their availability requirements to the total number of provisioned connections. Under dynamic traffic conditions with varying network load, simulation results show that RASP can provision reliable connections and satisfy Service Level Agreement (SLA) requirements. A competitive Blocking Probability (BP) and lower Backup Primary Resource Ratio (BPR) signify an improvement in resource utilization efficiency. A higher Backup Success Ratio (BSR) was also achieved under high Quality of Service (QoS) constraints. The significance of different availability requirements is evaluated by creating three categories, high availability, medium availability and low availability. These three categories represent three classes of service, with availability used as the QoS parameter. Within each class, the performance of RASP and CSP is observed and analyzed, using the parameters described above. Results show that both the BP and BPR increase with an increase in the availability requirements. The RSR decreases as the reliability requirements increase and a variation in BSR is also indicated. / Dissertation (MEng)--University of Pretoria, 2009. / Electrical, Electronic and Computer Engineering / unrestricted

This master‘s thesis deals with the calculation of losses depending on the configuration of the distribution network. The first part focuses on the general theory regarding some used calculation methods of steady operation. The next part is theoreticly dedicated to the technical losses, possibilities of their influencing and their calculation. In the practical part is carried out the choice of calculation method of steady operation. This method is implicated into the proposed program in programming environment MATLAB.Furthermore, on the basis of a partial measurement in the distribution network and using the proposed program are determined the sizes of offtakes of mesh network. For the existing mesh network is designed its radial operation. In the last part are calculated the losses of this network for both of these mentioned operations.

Avec les progrès dans les communications sans fil, le réseau maillé sans fils (WMN) est apparu comme une solution à la couverture et à la capacité limitée des réseaux d'infrastructure. Un WMN est un réseau ad-hoc multi-sauts dans lequel les routeurs participants acheminent le trafic pour le compte de tiers. Malgré les avantages et l'efficacité accrue de nombreuses applications, plusieurs problèmes doivent encore être résolus, notamment des facteurs critiques influant sur les performances des WMNs tels que l'évolutivité, la stabilité de la connectivité réseau, la qualité de service, la sécurité et les problèmes d'interférence. Face à ce défi, cette thèse explore une nouvelle approche des réseaux, à savoir le concept de réseau défini par logiciel (SDN). Dans une configuration SDN, l'intelligence située au niveau des périphériques réseau est déplacée dans une entité centrale communément appelée le contrôleur SDN. Dans cette architecture, le contrôleur SDN prend toutes les décisions et dicte à chaque périphérique réseau comment router les flux de données. Dans cette thèse, l'accent est mis sur l'évaluation des améliorations de la gestion de réseau que SDN pourrait apporter aux WMNs. En particulier, nous avons analysé et déterminé le type de granularité de contrôle SDN envisageable pour ce type de réseaux ainsi que les solutions techniques permettant de mettre en œuvre ce concept pour de meilleures performances. / With advances in wireless communications, Wireless Mesh Network (WMN) has emerged as one solution to the limited coverage and capacity of infrastructure networks. A WMN is a multihop ad-hoc network where participating routers forward traffic on behalf of others. Despite the advantages and increased efficiency in many applications, several challenges still need to be solved and especially critical factors influencing the performance of WMNs such as scalability, network connectivity steadiness, Quality of Service (QoS), security, and interference problems. In the face of this challenge, this thesis explores a new approach for networks, namely the concept of Software-Defined Network (SDN). In an SDN configuration, the intelligence located at network devices level is moved within a central entity commonly referred to as the SDN controller. In this architecture, the SDN controller takes all decisions and dictates to each network device how to route data flows. In this thesis, the focus is on evaluating network management improvements that SDN could make in WMNs. Particularly, we analyzed and determined what kind of SDN control granularity that could be envisaged for this type of networks as well as the technical solutions to implement this concept for better performance.

This thesis presents the work of a master degree project in mechatronics by two students from The Royal Institute of Technology. The project was carried out during spring 2017 in collaboration with Bosch Rexroth Mellansel as part of their desire to improve their operations. It is also in line with the Bosch Groups ambition to lead the development within Industry 4.0. The aim was to investigate the information need on a discrete manufacturing process and how radio-frequency identification (RFID) can be used to cover that need. The background research was made with qualitative methods using a literature review on relevant areas and a case study of Bosch Rexroth Mellansel. A discrete event simulation was created to confirm the possibilities of an RFID tracking system. It acted as a target for what the developed demonstrator should fulfil and was realised through a system of four wireless nodes connected in a mesh network. The plant in Mellansel partially implemented a Bosch standardised RFID system in parallel with the development of the demonstrator, which enabled a comparison of the two systems. The results show that from a tag event, which gives information on what, where and when, it is possible to, in real time, analyse and visualise valuable key performance indicators for a production process. It is also possible to use the data to automate transactions in an enterprise resource system which removes non-value adding activities from an operator while also ensuring consistency in the reporting procedure. The results indicate that benefits can be achieved. However, this requires further quantitative analysis before it can be fully confirmed and be used to push the development of Industry 4.0 forward. / Denna rapport presenterar ett examensarbete inom mekatronik av två studenter från Kungliga Tekniska Högskolan. Projektet genomfördes under våren 2017 i samarbete med Bosch Rexroth Mellansel som en del av deras strävan att förbättra sin verksamhet. Det ligger också i linje med Bosch koncernens ambition att leda utvecklingen inom Industri 4.0. Syftet var att undersöka informationsbehovet hos en diskret tillverkningsprocess och hur radio-frequency identification (RFID) kan användas för att täcka detta behov. Bakgrundsstudien gjordes med kvalitativa metoder som litteraturstudie inom relevanta områden och en fallstudie av en produktionsprocess inom Bosch Rexroth Mellansel. En simulering av produktionsprocessen skapades för att bekräfta möjligheterna av att använda ett RFID system för spårning av objekt. Den fungerade som ett mål för vad den utvecklade demonstratorn skulle uppfylla och realiserades genom en prototyp bestående av fyra trådlösa noder samlade i ett mesh nätverk. Parallellt med utvecklingen av demonstratorn gemomförde fabriken i Mellansel en del-implementering av en Bosch-standardiserad RFID lösning, vilket möjliggjorde en jämförelse av de två systemen. Resultaten visar att det från en avläsning av en tag, som ger information om vad, var och när, så är möjligt att i realtid analysera och visualisera värdefulla nyckeltal för en produktionsprocess. Det är också möjligt att använda data för att automatisera transaktioner i ett affärssystem som tar bort icke värdeskapande aktiviteter för operatören och samtidigt säkerställer en standardiserad rapporteringsprocess. Resultaten visar att fördelar kan uppnås men kräver ytterligare kvantitativ analys innan de kan bekräftas till fullo och användas för att driva utvecklingen av Industri 4.0 framåt.

According to a Gartner Group (www.gartner.com) report in September 2008, the worldwide telecommunications market is on pace to reach $2 trillion in 2008. Gartner predicts that by 2012, the ratio of mobile to fixed connections will exceed 4-to-1. The North American mobile data market grew to 141.1 million connections in 2007, with a compound annual growth rate of 41.7 percent. It is believed that a large portion will be ad hoc and multi-hop connections, which will open many opportunities for Mobile Ad hoc NETwork (MANET) applications and Wireless Mesh Network (WMN) applications. A MANET is a self-organizing multi-hop wireless network where all nodes participate in the routing and data forwarding process. Such a network can be easily deployed in situations where no base station is available, and a network must be build spontaneously. In applications such as battlefield communications, national crises, disaster recovery, and sensor deployment, a wired network is not available and ad hoc networks provide the only feasible means of communications and information access. Ad hoc networks have also become commonplace for gaming, conferencing, electronic classrooms, and particularly vehicle-to-vehicle communications. A Wireless mash network (WMN) is collection of mesh clients and mesh nodes (routers), with mesh nodes forming the backbone of the network and providing connection to the Internet and other network. Their rapid deployment and ease of maintenance are suitable for on-demand network such as disaster recovery, homeland security, convention centers, hard-to-wire buildings and unfriendly terrains. One important problem with MANET is the routing protocol that needs to work well not just with a small network, but also sustain efficiency and scalability as the network gets expanded and the application transmits data in greater volume. In such an environment, mobility, channel error, and congestion are the main causes for packet loss. Due to mobility of mobile hosts, addressing frequent and unpredictable topology changes is fundamental to MANET research. Two general approaches have been considered: connection-oriented approach and connectionless-oriented approach. In the former, the emphasis is on how to reconnect quickly with low overhead when a broken link occurs. Examples of this approach includes includes [5], [9], [10], [16], [26], [28], [29], [34], [44], and [45]. In contrast, connectionless-oriented approach focuses on minimizing the occurrence of broken links. We proposed one such scheme called Connectionless Approach (CLA) and . In CLA, the network area is divided into non-overlapping grid cells, each serving as a virtual router. Any physical router (i.e., mobile host), currently inside a virtual router, can help forward the data packet to the next virtual router along the virtual link. This process is repeated until the packet reaches its final destination. Since a virtual link is based on virtual routers which do not move, it is much more robust than physical links used in the connection-oriented techniques. Simulation results in our previous works and , based on GloMoSim , indicate that CLA performs significantly better than connection-oriented techniques (i.e., AODV, DSR, LAR, GRID, TMNR, and GPSR). The contribution of this work consists of investigating and developing new Connectionless-Oriented Approach for Mobile Ad Hoc Network. Two of the greatest impacts of this research are as follows. First, the new approach is targeted towards robustly support high mobility and large scale environment which has been adapted for vehicle-to-vehicle environment in . Second, the detailed simulations which compare eight representative routing protocols, namely AODV, DSR, LAR, GRID, TMNR, GPSR, CBF, and CLA, under high-mobility environments. As many important emergent applications of the technology involved high-mobility nodes, very little is known about the existing routing methods perform relative to each other in high-mobility environments. The simulation results provide insight into ad hoc routing protocols and offer guidelines for mobile ad hoc network applications. Next, we enhanced and extend the connectionless-oriented approach. The current connectionless-oriented approach, however, may suffer from packet drops since traffic congestion is not considered in the packet forwarding policy. We address this weakness by considering the connectionless-oriented approach with a collision avoidance routing technique. After that, we investigate techniques to enforce collaboration among mobile devices in supporting the virtual router functionality. Many works have been published to combat such problem - misbehaving nodes are detected and a routing algorithm is employed to avoid and penalize misbehaving nodes. These techniques, however, cannot be applied to the connectionless-oriented approach since any node in the general direction towards the destination node can potentially help forward the data packets. To address the security and cooperation issues for connectionless-oriented approach, we introduce a cooperation enforcement technique called 3CE (3-Counter Enforcement). In addition, wireless mesh networks have become increasingly popular in recent years. Wireless mash network (WMNs) are collection of mesh clients and mesh nodes (routers), with mesh nodes forming the backbone of the network and providing connection to the Internet and other network. We propose a paradigm that combines virtual routers and mesh nodes to create a hybrid network call VR-Mesh Network. This hybrid network can reduce number of mesh node needed without decrease the performance of the network.

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The power grid has changed a great deal from what has been generally viewed as a traditional power grid. The modernization of the power grid has seen an increase in the integration and incorporation of computing and communication elements, creating an interdependence of both physical and cyber assets of the power grid. The fast-increasing connectivity has transformed the grid from what used to be primarily a physical system into a Cyber- Physical System (CPS). The physical elements within a power grid are well understood by power engineers; however, the newly deployed cyber aspects are new to most researchers and operators in this field. The new computing and communications structure brings new vulnerabilities along with all the benefits it provides. Cyber security of the power grid is critical due to the potential impact it can make on the community or society that relies on the critical infrastructure. These vulnerabilities have already been exploited in the attack on the Ukrainian power grid, a highly sophisticated, multi-layered attack which caused large power outages for numerous customers. There is an urgent need to understand the cyber aspects of the modernized power grid and take the necessary precautions such that the security of the CPS can be better achieved. The power grid is dependent on two main cyber infrastructures, i.e., Supervisory Control And Data Acquisition (SCADA) and Advanced Metering Infrastructure (AMI). This thesis investigates the AMI in power grids by developing a testbed environment that can be created and used to better understand and develop security strategies to remove the vulnerabilities that exist within it. The testbed is to be used to conduct and implement security strategies, i.e., an Intrusion Detections Systems (IDS), creating an emulated environment to best resemble the environment of the AMI system. A DoS flooding attack and an IDS are implemented on the emulated testbed to show the effectiveness and validate the performance of the emulated testbed. / M.S. / The power grid is becoming more digitized and is utilizing information and communication technologies more, hence the smart grid. New systems are developed and utilized in the modernized power grid that directly relies on new communication networks. The power grid is becoming more efficient and more effective due to these developments, however, there are some considerations to be made as for the security of the power grid. An important expectation of the power grid is the reliability of power delivery to its customers. New information and communication technology integration brings rise to new cyber vulnerabilities that can inhibit the functionality of the power grid. A coordinated cyber-attack was conducted against the Ukrainian power grid in 2015 that targeted the cyber vulnerabilities of the system. The attackers made sure that the grid operators were unable to observe their system being attacked via Denial of Service attacks. Smart meters are the digitized equivalent of a traditional energy meter, it wirelessly communicates with the grid operators. An increase in deployment of these smart meters makes it such that we are more dependent on them and hence creating a new vulnerability for an attack. The smart meter integration into the power grid needs to be studied and carefully considered for the prevention of attacks. A testbed is created using devices that emulate the smart meters and a network is established between the devices. The network was attacked with a Denial of Service attack to validate the testbed performance, and an Intrusion detection method was developed and applied onto the testbed to prove that the testbed created can be used to study and develop methods to cover the vulnerabilities present.

In this work, a new multicast routing algorithm for wireless networks is presented. The algorithm, called SWIM (Source-initiated WIreless Multicast), is a depth-optimal multicast tree formation algorithm. SWIM is fully distributed and has an average computational complexity of O(N 2 ). SWIM forms a shared tree from the source(s) to destinations / yet, as a by-product, it creates a multicast mesh structure by maintaining alternative paths at every tree node. This makes SWIM suitable for both ad hoc networks and access networks with multiple gateways. An extension to the main algorithm is presented for the use in dynamic networks with mobility and/or dynamic destination group. Performance of SWIM is studied with simulations and is compared to other algorithms in the literature. Due to depth optimality, SWIM achieves a lower average and maximum delay than the compared algorithms. The throughput performance is found to be high. Working capability with rateless codes are also studied.