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zlomekFS is a distributed file system that supports disconnected operation using local cache. During synchronization of local changes it offers easyto-use conflict resolution mechanism. Further improved it became a file system with no specific kernel code. It has therefore a good potential in future public use. As the content of this file system can be updated by many users, keeping history of the changes can be a useful feature. This thesis implements file versioning in zlomekFS, answering the questions such as how to store and access the history. On top of the versioning, the possibility of consistent backup is introduced into the file system. New functionality is derived from the analysis of other file systems with similar features and selection of the most suitable approach for zlomekFS.

zlomekFS is a distributed file system that supports disconnected operation using local cache. During synchronization of local changes it offers easytouse conflict resolution mechanism. Further improved it became a file system with no specific kernel code. It has therefore a good potential in future public use. As the content of this file system can be updated by many users, keeping history of the changes can be a useful feature. This thesis implements file versioning in zlomekFS, answering the questions such as how to store and access the history. On top of the versioning, the possibility of consistent backup is introduced into the file system. New functionality is derived from the analysis of other file systems with similar features and selection of the most suitable approach for zlomekFS.

P2P is increasingly gaining its popularity for streaming multimedia contents. The architecture of streaming has shifted from traditional client server architecture to P2P architecture. Although it is scalable and robust it faces its own challenges and problems such as churn. In tree topology frequent joining and leaving of users in search for better quality and reliable streaming makes the P2P network instable. This thesis provides an effective approach to achieve a resilient network for streaming. Relying on a single tree to receive data from single parent may leave the user deprived of getting the data if any of its ancestors leaves the network. Therefore we present an ideal solution to this problem by introducing a backup tree for the existing base tree. The backup tree is constructed based on parameter such as bandwidth and delay. In case of failure of a node, its children along the tree receive the data from the nodes of backup tree. We present an efficient algorithm for the construction of base tree as well as the backup tree which are based on normalization of two entities of nodes: bandwidth and delay. Through mathematical formulation and experimental setups we show that introducing a backup tree for an existing base tree can help provide resilience to the network. / UOIT

In recent years, the applications of wireless mesh network in the embedded systems have become more widely. It's an important issue that how to consume lower energy and transfer data stably based on energy considerations. The embedded systems must have the appropriate routing protocol for low power consumption and stable long-distance data transmission. In this paper, a routing protocol is proposed with sequential repair and backup routing protocol(Ad Hoc On-Demand Distance Vector Routing-Sequential Repair and Backup Routing Protocol, AODV-SRBR Protocol), that can reduce the number of transceivers and have a stable connection. In the proposed routing protocol, the node of network can create multi-route message through decoding the path information of packets. Using a complete routing information can reduce the number of route request packets efficiently. when the link is broken, the proposed protocol can repair the data transmission by sequential repair or select backup routing. In this paper, we implement the routing protocol to verify a multi-hop connection and data transfer in the general environment. The performance of AODV-SRBR and AODV is compared and simulated by NS2. The proposed routing protocol can achieve same transmission efficiency in the fewer route request packets, fewer maintance packets and fewer transmit and receive times according to the simulation result. By stable connection¡Blow power consumption and multi-hop data transfer, we expect that the proposed routing protocol on the embedded systems platform can be extended in large sensor mesh network.

An ad-hoc network operates without a central entity or infrastructure, and is composed of highly mobile hosts. In ad-hoc network, routing protocols are with host mobility and bandwidth constraints. There have been many recent proposals of routing protocols for ad-hoc networks. A recent trend in ad hoc network routing is the reactive on-demand philosophy where routes are established only when required. AODV(Ad-hoc On-demand Distance Vector routing) evaluates routes only on an as-needed basis and routes are maintained only as long as they are necessary. Because the network topology changes frequently in ad-hoc networks, some on-demand protocols with multi-paths or backup routes have been proposed. Sung-Ju Lee and Mario Gerla proposed an AODV-BR scheme to improve existing on-demand routing protocols by creating a mesh and providing multiple alternate routes . The algorithm establishes the mesh and multi-path using the RREP (Route Reply) of AODV, which does not transmit any extra control message. In this paper, we propose two schemes : AODV-ABR(Adaptive Backup Route) and AODV-ABL (Adaptive Backup Route and Local repair) to increase the adaptation of routing protocol to topology changes by modifying AODV-BR. In AODV-ABR, the alternative route can be creating by overhearing not only RREP packets but also data packets. AODV-ABL combines the benefits of AODV-ABR and Local Repair. Finally, we evaluate the performance improvement by simulation.

Mobile ad hoc network is an architecture which do not exist any infrastructure or centralized administration. There are many routing protocols have been proposed so far, such as AODV, DSR and CGSR. These protocols were classified as reactive in which routes are established only when required. Due to the movement of mobile nodes, network topology changes frequently, and the routing path could be broken easily. This phenomenon will cause higher routing overhead and delivery latency. In conventional routing protocols, the source-destination pair only establishes a single path for data transmission. These routing scheme, however, suffer from the drawback of node movement. When route broken, the source node must reconstruct another new path. This paper presents an adaptive routing protocol named Adaptive Route Selection Scheme of Multiple Paths for Mobile Ad Hoc Network (ARSMA). The aim of the work is to improve the delivery ratio. In the route request phase, source nodes will discovery two routes to the destination node, one for primary path, and the other for the backup path. During the discovery procedure, each node will estimate the link expire time through the movement speed and direction of the precursor node. When a link breakage is about to occur, source node will try to switch the transmission to the backup route.The simulation result shows that ARSMA is able to achieve a remarkable improvement in delivery ratio and end-to-end dealy.

Die Datensicherung stellt derzeit eine der wichtigsten Aufgaben bei der Administration von Rechnersystemen dar. Vorallem in heterogenen Netzwerken mit vielen zu verarbeitenden Daten, auch unterschiedlicher Betriebssysteme, muss die Sicherung und Rueckstellung entsprechend den technologischen und organisatorischen Bedingungen des Bereichs effektiv umgesetzt werden. Deshalb wird ein allgemeines Datensicherungskonzept definiert, nach dem die Planung und Durchfuehrung der Sicherung und Rueckstellung von Daten einschliesslich der dazu benoetigten Software und Speicherhardware organisiert werden kann. Einige Datensicherungssysteme und Speichermedien werden analysiert und fuer den Einsatz bewertet. Am Beispiel der Fakultaet fuer Informatik wird ein Technologievorschlag fuer die Organisation der Datensicherung gemacht. Zur konkreten Unterstuetzung des Systemadministrators bei der Planung und Durchfuehrung der Datensicherung werden einige Softwarewerkzeuge vorgestellt. Die Implementation erfolgte unter den Betriebsystemen MS-DOS und UNIX in Perl.

Workshop "Netz- und Service-Infrastrukturen" Ein Backupsystem für das Backup inhomogener Umgebungen. Das komplette Betriebssystem wird gesichert, und kann wiederhergestellt werden. Haupteinsatz derzeit im Root-Lab, um eine Mehrfachnutzung der Rechner des Labors sicherzustellen.

Vi har tidigare skrivit en rapport över CCTV-systemet som Karlshamns hamn använder sig av. Problemen som den rapporten hade sitt fokus på löstes men det återstod fortfarande flertalet problem som rapporten ej tog upp. Denna rapport är därför ett efterföljande från det föregående arbetet om hamnens kameraövervakning och belyser istället för ett enda stort problem ett flertal mindre. Karlshamns Hamn AB ville att vi skulle behålla vår frågeställning och arbeta vidare med denna i fler aspekter än föregående arbete. Frågeställningen som används i arbetet är: Vad behöver göras för att få bästa kvalité på hamnens kameror 24/7? Vilket alltså innebär att vår uppgift med rapporten är att arbeta för att CCTV-systemet som finns i Karlshamns hamn skall hålla så bra standard som möjligt, dagtid som nattetid. För att arbeta mot detta såg vi över hamnens kameraövervakning igen och tog ut de delar som ansågs vara de största problemen. Resultaten togs fram med hjälp av hamnens dokument, dokument över delarna som vi letat upp på internet och genom att kontakta företag. Med dessa resultat så såg vi hur allvarliga problemen var och hur de kan lösas eller förhindras. Själva syftet med arbetet är dock inte att direkt lösa alla problemen som finns utan att belysa dem och ge förslag på hur de skulle kunna lösas. I arbetet kommer hamnen nämnas som Karlshamns Hamn AB när det handlar om hamnen som kund eller organisation. När hamnen istället ses som säkerhetsobjekt eller hamnområde i arbetet benämns det som Karshamns hamn eller hamnen.