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  • 51.
    Azfar, Abdullah
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Multiple Escrow Agents in VoIP2010Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Using a Key escrow agent in conjunction with Voice over IP (VoIP) communication ensures that law enforcements agencies (LEAs) can retrieve the session key used to encrypt data between two users in a VoIP session. However, the use of a single escrow agent has some drawbacks. A fraudulent request by an evil employee from the LEA can lead to improper disclosure of a session key. After the escrow agent reveals the key this evil person could fabricate data according to his/her needs and encrypt it again (using the correct session key). In this situation the persons involved in the communication session can be accused of crimes that he or she or they never committed. The problems with a single escrow agent becomes even more critical as a failure of the escrow agent can delay or even make it impossible to reveal the session key, thus the escrow agent might not be able to comply with a lawful court order or comply with their escrow agreement in the case of data being released according to this agreement (for example for disaster recovery).

    This thesis project focused on improving the accessibility and reliability of escrow agents, while providing good security. One such method is based on dividing the session key into M chunks and escrowing the chunks with M escrow agents. Using threshold cryptography the key can be regenerated by gathering any N-out-of-M chunks. The value of M and N may differ according to the role of the user. For a highly sophisticated session, the user might define a higher value for M and N for improved, availability, reliability, and security. For a less confidential or less important session (call), the value of M and N might be smaller. The thesis examines the increased availability and increased reliability made possible by using multiple escrow agents.

  • 52.
    Azzolin de Carvalho Pires, Gustavo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Multi-Cell Admission Control for WCDMA Networks2006Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    It has long been recognized that in multi-cell WCDMA networks the admission of a new session into the system can have undesirable impact on the neighboring cells. Although admission control algorithms that take into account such multi-cell impact have been studied in the past, little attention has been paid to multi-cell admission and rate control algorithms when traffic is elastic. In this thesis, we propose a model for multi-cell multi-service WCDMA networks to study the impact of multi-cell admission and rate control algorithms on key performance measures such as the class-wise blocking and outage probabilities, block error rates, and the noise rise violation probabilities. By means of simulation we compare the performance of load based multi-cell algorithms with that of a single cell algorithm. We find that with multi-cell based algorithms the system capacity and performance (in terms of the above mentioned measures) are (in some cases significantly) better in homogeneous load scenarios as well as in the heterogeneous ’hotspot’ and ’hotaround’ scenarios.

  • 53.
    Babu, Bibin
    Linköpings universitet, Institutionen för systemteknik. Linköpings universitet, Tekniska högskolan.
    Connected Me: Hardware for high speed BCC2012Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Body coupled communication (BCC) is a hot topic in personal networking domain. Many works arepublished suggesting different architectures for BCC since its inception in 1995 by Zimmerman. The number ofelectronic gadgets used by a single person increases as time pass by. Its a tedious job to transfer data betweenthen from a user point of view. Many of these gadgets can share their resources and save power and money.The existing wired or wireless networks does not meet the requirements for this network like scalable data rate,security etc. So here comes the novel idea of using human body as communication medium. The aim of thisthesis is to realize a hardware for BCC based on wide band signaling as part of a big project.The human body consists of 70% of water. This property makes the human body a fairly good conductor.By exploiting this basic property makes the BCC possible. A capacitance is formed if we place a metal platenear to the human body with the skin as a dielectric. This capacitance forms the interface between the humanbody and the analog front-end of the BCC transceiver. Any other metal structures near to the human body canattenuate the signal.A first-order communication link is established in software by the human body model and the transceiver inthe loop along with noise and interference. This communication link is used to verify the human body modeland the base band model done as part of the same big project. Based on the results a hardware prototype isimplemented. Measurements are taken in different scenarios using the hardware setup. The trade-off betweendesign parameters are discussed based on the results. At the end, it suggests a road map to take the projectfurther.

  • 54.
    Backlund, Ola
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Policy-based IP services over UMTS2001Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Providing services over IP with real-time characteristics are one of the challenges that the next generation UMTS operators arefacing. Offering these services with adequate quality will be an important task in the management of their networks, which to alarge extent will be built on IP technology. Policy-based network management is an approach to improving network performanceand QoS. This is a network management model, suitable for highlevel service management that has been proposed as a promisingsolution for dynamic QoS. It is well suited for networks with hierarchical service models, which is the situation encountered inUMTS.

    The aim of this Master thesis is to examine IP services providedover UMTS based on the ideas from policy-based network technology and how they can be applied to this next generation ofcellular systems. A framework for policy-based QoS management support is outlined for the packet domain of UMTS, which is basedon the principles and experience derived from policy-based network technology found in fixed networks. A description of thefunctions and capabilities of a policy-based management system designed for UMTS is given, and the QoS related problems inUMTS are identified in order to evaluate the bottlenecks for improving service quality. The report ends with a proposal to howTelia may provide UMTS access to a IP access node that is currently being tested and developed in co-operation with othermanufacturers. Two possible solutions are described and evaluated from a QoS and architectural perspective.

  • 55.
    Badinson (nee Hossieni), David
    KTH, Tidigare Institutioner, Teleinformatik. KTH, Skolan för informations- och kommunikationsteknik (ICT).
    Adding Gigabit Ethernet to an ATM Switch1999Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This document contains the outcome of the final version of my thesis project: Adding Gigabit Ethernet access to an ATM switch. The accelerating growth of LAN (Local Area Network) traffic and growing number of complex and bandwidth hungry applications, such as, fast Interent, video telephony, voice over Internet, etc., is pushing  network administrators to look to high-speed network technologies.

    The Gigabit Ethernet and ATM are two dominant technologies in network backbone which are operating at gigabit-speed. These two technologies are considered to be competitors, but in reality they are appropriate for different applications and they are not equal substitute for each other. What we can do in this connection is to take up the advantages of both technologies and try to on somehow integrate them, in order to achieve high performance and powerful networks which are extremely demanded for future applications.

    The purpose with this project was to study the ATM and Gigabit Ethernet technologies and investigate the possibility of integrating them. This report includes an introduction to both technologies and design for a Gigabit Ethernet access card to an ATM switch. The document presents the including components in the card and gives a detailed description for each of components.

  • 56.
    Baecklund, Fredrik
    KTH, Tidigare Institutioner, Teleinformatik.
    Software architecture for a scalable carrier class edge router1999Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    With the rapid growth of the Internet in the recent years and the expected future growth puts greater demands on high performance access and routing  technologies. The Ericsson AXI 510 Edge Router is a step in the right direction but to provide enough performance for future demands, a highly scalable system has to be designed. This new system is probably going to be based on a distributed architecture.

    In this MSc thesis the author discusses possible ways of designing a scalable distributed edge router software architecture and what implications the distributed architecture has on different edge router applications such as Network Address Translation, tunnel termination and management etc. Furthermore, the author presents a design proposal for a fully distributed architecture.

  • 57.
    Bai, Xin
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Broadband Wireless Access in Disaster Emergency Response2006Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The “WLAN in Disaster Emergency Response” (WIDER) project has developed and implemented an emergency communication system. It provides network and communication services to relief organizations. In order to guarantee the stable and efficient connectivity with a high quality of service (QoS) for the end user, and to make the WIDER system more adaptive to the disaster area, the IEEE 802.16 specification based broadband wireless access solution is adopted. This thesis work aims at evaluating and testing the WIDER system integrated with WiMAX. By learning and analyzing the technology, the benefits and perspective for WIDER using WiMAX are described. A WiMAX solution was configured and integrated into the WIDER system. A series of tests and measurements provide us the performance of the WiMAX solution in throughput, QoS, and reality. The tests helped us to learn and verify the improvements for WIDER due to WiMAX.

  • 58.
    Becker, Kalle
    KTH, Tidigare Institutioner, Teleinformatik.
    Calling your mailbox1998Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This paper presents how the company for whom this work was preformed should act to add an email reading feature to their platform. It also includes an evaluation of the usability of such a system (called Popeye).

    A field trial with Popeye was carried out, and also analyzed to understand both how users want to use this kind of service and also to evaluate speech technology in such applications.

    This paper also briefly describes the platform and why it is a good idea to use Microsoft Transaction Server (MTS) together with COM when building large systems in a Windows NT environment.

    Two different approaches to creation of this feature are discussed and the design of a COM interface was done. This interface will let voice mail vendors connect with the system and this will minimize the hardware that the telecom operators will have to buy and maintain.

    The solution I prefer is the one that means that the company has to build a complete new product. This solution will be harder to implement but I think that it will give the company the most benefits in the end. My conclusions can be read in chapter 5.

  • 59.
    Beermann, Mikael
    KTH, Tidigare Institutioner, Teleinformatik.
    Implementation of the Mobile Floating Agent Technique1996Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The computer has undergone an explosive development since they first arrived. Today nearly everybody uses computers more or less frequently. The trend is now that everyone has a little computer connected to others in a network. The computing power has become more decentralized, and therefore the need for communication has increased. Another thing that has changed the pattern is that the computers has become so small that it is no longer any problem to move them as long as one does not care about the network support, but of course one would like to have both the mobility and the network support.

    In my master thesis project I have implemented and evaluated parts of a new approach for dealing with the problems with mobility. This approach is called the mobile floating agent technique, and was developed by George Y. Liu at Ericsson Radio Systems AB, Kista. The main idea behind this is to have floating agents in the network, i.e. software entities that are virtually floating around in the network, arranging files and resources for the mobile user so that he can connect to a server in his neighbourhood, instead of connecting to his own server far away.  I have implemented a simple file system testbed that uses the floating agent technique for caching purposes. There are two reasons for doing this implementation. The reason is for evaluation of the caching features, and the second reason is to have a platform to implement more advanced agent functions on.

    The design of the system has been done in an object oriented style, and the implementation has been done in C++.The system consists of two parts. One part is the client software, which has been implemented in another project, but modified by me, and runs on aPC with the Windows95 OS. The other part is the network part of the system, i.e. the part of the system that is not running in the client, is made for running on an UNIX station. The network part of the system consists of two parts itself. There are mobile floating agent managers, that manages the whole system, and agents, that serves the mobile clients, and communicates with both the client software and the mobile floating agent managers.

    In the evaluation part of the project I have compared the delay acquired when accessing a file in a remote network with and without an agent. I finally came to the conclusion that the gain won with the use of caches in the agents is maybe not as large that one should use caching as the primary object of the agents.

  • 60.
    Beermann, Mikael
    KTH, Tidigare Institutioner, Teleinformatik.
    Implementation of the Mobile Floating Agent Technique1996Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The computer has undergone an explosive development since they first arrived. Today nearly everybody uses computers more or less frequently. The trend is now that everyone has a little computer connected to others in a network. The computing power has become more decentralized, and therefore the need for communication has increased. Another thing that has changed the pattern is that the computers has become so small that it is no longer any problem to move them as long as one does not care about the network support, but of course one would like to have both the mobility and the network support.

    In my master thesis project I have implemented and evaluated parts of a new approach for dealing with the problems with mobility. This approach is called the mobile floating agent technique, and was developed by George Y. Liu at Ericsson Radio Systems AB, Kista. The main idea behind this is to have floating agents in the network, i.e. software entities that are virtually floating around in the network, arranging files and resources for the mobile user so that he can connect to a server in his neighbourhood, instead of connecting to his own server far away.

    I have implemented a simple file system testbed that uses the floating agent technique for caching purposes. There are two reasons for doing this implementation. The reason is for evaluation of the caching features, and the second reason is to have a platform to implement more advanced agent functions on.

    The design of the system has been done in an object oriented style, and the implementation has been done in C++.The system consists of two parts. One part is the client software, which has been implemented in another project, but modified by me, and runs on aPC with the Windows95 OS. The other part is the network part of the system, i.e. the part of the system that is not running in the client, is made for running on an UNIX station. The network part of the system consists of two parts itself. There are mobile floating agent managers, that manages the whole system, and agents, that serves the mobile clients, and communicates with both the client software and the mobile floating agent managers.

    In the evaluation part of the project I have compared the delay acquired when accessing a file in a remote network with and without an agent. I finally came to the conclusion that the gain won with the use of caches in the agents is maybe not as large that one should use caching as the primary object of the agents.

  • 61.
    Bektesevic, Edin
    KTH, Tidigare Institutioner, Teleinformatik.
    Embedded Linux for Purposes of Internet Appliances: (a.k.a. ‘The Wanderer Project’)1999Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    As the Internet continues to grow, now new Internet appliances are being marketed. At the same time, Linux is gradually becoming a competitive choice for desktop, server and embedded applications. How do these two facts relate to each other? What should be the position of Linux in Internet appliances, and how interesting is Linux? Where are the Internet appliances really positioned in terms of their needs for an operating system? How is Linux implemented in embedded applications?

    These are just some of the questions posed during this MSc. Project that this report aims to answer. In addition, we will examine how Linux is used in embedded applications and what it provides in terms of achieving their goals. Also, we will take a look at the compression methods that can be used for system size reduction and analyze their costs.

    The report will show that Linux is a competitive alternative for devices like WebPAD, that it leaves space for further time and cost efficient improvements, and that Internet appliances can get most of the benefits of Linux during its further evolution relatively cheaply.

  • 62.
    Bennani, Zakaria
    KTH, Tidigare Institutioner, Teleinformatik.
    Quality of Service Support for Wireless LANs2000Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    As the research and development of mobile computing is becoming increasingly interesting and important to corporations and private users, great efforts are being made to ensure that the wireless network technology is being developed to match the performance level showed by wired network technologies. Introducing wireless mobile computing into already existing and operational situations, that have up to date been taken care of with wired technology, should not mean a degradation of the existing performance level. In other words, there should not be any decrease in the quality of service experienced by the end users due to the mobility or wireless factor.

    When developing quality of service support mechanisms that use characteristics specific to the Internet Protocol, considerations have to be made to make certain that the solutions and implementations developed will be deployable with the next generation Internet Protocol, IPv6. Since the ever decreasing address space in IPv4 is becoming more and more of a problem, at some point migration to IPv6 has to be made. Therefore, this thesis will base its developments on the use of IPv6.

    The thesis concerns the problem of providing statistical QoS guarantees for multimedia applications running over a wireless LAN such as WaveLAN. Using the DiffServ model and support of IPv6, we develop mechanisms for managing QoS and mobility. With the use of pre-connection schemes and a domain routing approach, Mobile Node mobility and Handoffs are handled in such a way to diminish latencies that occur when in-LAN and cross-LAN handoffs are made. To handle QoS guarantees, a bandwidth broker placed in the Access Points manages bandwidth allocations for different cells and configures the traffic parameters of each mobile so that the usage of the wireless MAC layer is controlled. The border router is connected via ATM to core routers in several places in France. Experimentation on the platform involves a DIS application (Distributed Interactive Simulation) running at different sites.

    The development work is done on FreeBSD systems in C.

  • 63.
    Bennehag, David
    et al.
    Högskolan Väst, Institutionen för ingenjörsvetenskap, Avd för automation och datateknik.
    Wulcan, Alexander
    Högskolan Väst, Institutionen för ingenjörsvetenskap, Avd för automation och datateknik.
    Claesson, ommy
    Högskolan Väst, Institutionen för ingenjörsvetenskap, Avd för automation och datateknik.
    Förstudie till ett stadstäckande och öppet WiFi i Trollhättan2013Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Förstudien behandlar den tekniska delen av ett teoretiskt stadstäckande öppet WiFi i Trollhättan, Sverige. Trollhättans kommun beställde en förstudie från Högskolan Väst som skulle agera beslutsunderlag till hur de skulle ta ärendet vidare. Studien är begränsad till den tekniska biten, där bland annat val av utrustning, trådlösa tekniker och riskanalys av nätverket ingår. Arbetet varit väldigt teoretiskt inriktat med en metod som till största del består utav att samla information och kunskaper från vetenskapliga rapporter, teknikorienterade hemsidor och andra relaterade arbeten.De trådlösa standarder som jämfördes teoretiskt i förstudien var 802.11g och 802.11n. 802.11n valdes som den standarden som bäst passade just detta nätverk, främst för dess positiva egenskaper när det gäller täckning, hastighet och bakåtkompatibilitet. 802.11n seräven ut att garantera en säker framtid när det gäller implementering i mobila enheter. Föreslaget på utrustning består av två olika accesspunkter, antingen 2602e eller 3602e beroende på den slutgiltiga budgeten. Dessa produkter är från Cisco och klarade olikastresstester med bra resultat samtidigt som de stödde den föreslagna standarden 802.11n. WLAN controllern (Ciscos 5500-serie) som valdes ut stödjer det krav på antal accesspunkter som bestämts, samtidigt som den lämpar sig bra för eventuella framtidakrav. Routern till detta nätverk är en Cisco 891-router. Anledningen till att denna router valdes var för att den har 4 portar som kan ge ström över Ethernet till accesspunkterna. Säkerhetsanalysen gjordes med hjälp utav CORAS-metoden där det diskuteras vilka riskernätverket kan ställas inför och vad dessa risker kan få för konsekvenser. Försök till att hitta lösningar som var direkt applicerbara på det stadstäckande öppna nätverket gjordes även.Förstudien avslutas med en kostnadsberäkning av nätverket, baserad på andras tidigare arbeten och deras kostnader, speciellt från Jönköping, Helsingborg och Mountain View.

  • 64.
    Bentahar, Younes
    KTH, Skolan för informations- och kommunikationsteknik (ICT).
    DNS prestanda2013Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    Use of computers and computer networks is nowadays a part of everyday life. You do not use them only at home when you sit at you computer, but you can use them all the time everywhere. This can involve everything from surf to any website when you are at home, to checking your email on your mobile when you are on your way to work. Most people do not think about how it really works when they try to access a web page by typing the address into their browser, but something that most people probably notice is how long it can sometimes take to access a web page.

    All items which are directly connected to the IP network have a unique IP address that is used to make it possible to communicate. The IP address is either a period separated sequence of digits representing 32 bits or a colon separated sequence of digits representing 128 bits, depending on whether the address is an IPv4 or IPv6 address. Such numeric sequences are often difficult for us humans to remember therefore, the domain name system (DNS) was constructed. DNS makes it possible for us to write addresses in a textual format to access an item stored in a device connected to the network. DNS can be seen as a directory for the network and can be compared to a telephone directory, where if you know the name of a person can find his or her phone number.

    This thesis will describe how the various address translations are done by using DNS. It will also examine how much impact DNS has on the experienced delay from the time you type a web page address in the address bar of your browser to the actual time you reach the website. A survey of DNS performance will be presented to investigate how much delay can be reduced by using one of Sweden's two most well-known public DNS servers (Google Public DNS and OpenDNS) instead of the normal default DNS server provided by one's Internet service provider (ISP).

    The survey will also show how the DNS lookup waiting time changes at different times of day and different days of the week. The purpose of this work is to provide a basic explanation of what DNS is and increase the understanding of how an everyday user in a simple way can make their network usage more effective by getting their DNS lookups to occur faster.

    The conclusion from this thesis is that the alternative DNS server, Google Public DNS has the fastest DNS lookup time for this particular computer which the measurement was carried on. But this tells us nothing about whether the case for any other network users because the observed DNS performance has a large extent dependent on the ISP you are connected to, and what place you are at.

  • 65. Berg, Jacob
    et al.
    Landin, Niclas
    Kommunikationskort2017Independent thesis Basic level (university diploma), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Raytelligence har utvecklat en radar som kan registrera rörelse och hjärtfrekvens hos människor. Datan från radarn skickas över Universal Serial Bus (USB) till en extern dator. För att produkten ska bli mer användarvänlig krävs en bättre kommunikationslösning. Projektet går ut på att implementera en trådlös kommunikation i form av bluetooth och Wireless Local Area Network (WLAN) som kan skicka datan från radarn trådlöst till en extern dator eller mobil enhet. I rapporten beskrivs de olika metoderna som använts för att åstadkomma den trådlösa kommunikationen. Det beskrivs passande gränssnitt, val av passande kommunikationsmodul, implementering och kalibrering av antenn, val av komponenter och olika sätt att motverka Elektromagnetisk Interferens (EMI) för att få bra förutsättningar för en Elektromagnetisk kompatibilitet (EMC)-certifiering. Resultatet av projektet är en produkt som bygger på kommunikationsmodulen RS9113 och Raytelligence radarkort.

  • 66.
    Berggren, Anders
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Borg, Martin
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    A Comparative Study ofTwo Multicast Routing Algorithms2002Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This Master Thesis examines several aspects of two different multicast forwarding algorithms. The scaling properties of the currently used algorithms were examined under different criteria, such as delay, traffic concentration, and size of the routing tables.

    Many new Internet applications, such as videoconferencing, resource discovery, Internet radio and online games, depend on a network support for efficient point-to-multipoint communication. Sending identical data to a group of receivers using a series of unicast transmissions obviously has massive scaling problems. Multicasting provides an efficient and elegant solution that significantly reduces the total bandwidth demand as well as the load on both senders and intermediate routers.

    In this report we study two multicast routing algorithms, source based trees (SBT) and core based trees (CBT). SBT builds one delivery tree per source and group by flooding the initial packet through the entire network, and then removing the links that do not lead to group members (“pruning”). To be able to discover new members, flooding must occur periodically. CBT on the other hand, builds one delivery tree per group, shared by all sources. There is one core router per group and members must explicitly join the delivery tree by notifying the core. Off-tree sources must tunnel their traffic to the core for distribution along the tree.

    SBT has two main drawbacks. Firstly, the maintenance of the delivery tree requires periodic flooding of the network. Furthermore, SBT routers must keep state that grows as the product of the number of sources and the number of groups. CBT solves both of these scaling problems, but the shared tree will often lead to sub-optimal paths and increased delay. The traffic may also be concentrated on fewer links than in SBT.

    We compared the characteristics of the SBT and CBT algorithms in different network topologies using a simulation program. Since existing network simulation tools were found to be poor when it came to multicasting, we decided to develop a new network generator and simulator tool with multicasting aspects in focus. We also developed a tool to visualize the networks generated by the simulator and monitor the traffic. The report presents many simulation results that illustrate the significance of different trade-offs between SBT and CBT. Performance characteristics such as delay, join latency, tree size, total traffic and traffic concentration are analysed and examined.

    The conclusion is that each protocol can be preferable in certain scenarios, depending on how important the different parameters are. CBT always performs better than SBT for single source applications if the core can be placed at the sender’s local router. However, this core placement is not necessarily optimal for CBT. The situation is more complex in groups with several sources. There is a trade-off between the scaling problems of SBT and the increased delay and traffic concentration of CBT.

  • 67.
    Bergholm, Johan
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Gallardo, Sascha
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Svensson, Jonny
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Positionering och Spårning av mobila enheter, ur ett IT–forensiskt perspektiv2013Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    I dagens Sverige så har de mobila enheterna en självklar plats i våra fickor, likväl som i vårt samhälle och i dess brottslighet, vilket gör att det sedan några år är att anse självklart att de även har en central roll i IT–forensiska utredningar inom våra polismyndigheter. Men vid sidan av konkreta bevis för begångna brott lagrar enheterna dessutom ofta data som kan användas för att spåra enheten, och därmed också dess brukare, över tid, vilket givetvis är av intresse av polismyndigheter men skulle även kunna vara av stort intresse för exempelvis försäkringsbolag och andra delar av den 'civila sektorn' som driver utredningar men som saknar polisens befogenheter. För att ge ett så brett användningsområde som möjligt fokuserar därför rapporten inte bara på datat som är tillgängligt från den faktiska enheten och hur de kan användas för spårning och positionering, utan försöker även på praktiskt väg undersöka i vilken grad dessa metoder kan utföras med allmänt tillgänglig mjuk- och hårdvara.

  • 68.
    Berglund, Emil
    et al.
    Uppsala universitet, Humanistisk-samhällsvetenskapliga vetenskapsområdet, Samhällsvetenskapliga fakulteten, Institutionen för informatik och media.
    Facklam, Alexander
    Uppsala universitet, Humanistisk-samhällsvetenskapliga vetenskapsområdet, Samhällsvetenskapliga fakulteten, Institutionen för informatik och media.
    Framgång eller förfall?: Utvecklingen, riskerna och potentialen av BYOD2016Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Uppsatsen undersöker fenomenet Bring Your Own Device (BYOD), dess för- och nackdelar samt hur riskerna BYOD medför kan hanteras. För att uppnå detta har en litteraturstudie genomförts. Denna kompletteras av en enkätstudie på Stockholms Läns Landsting och tre intervjuer på Uppsala Kommun med målet att se hur dessa organisationer hanterar BYOD. Arbetet ger en djup insikt i BYOD olika aspekter och visar även på hur de risker som uppkommer kan hanteras.

  • 69.
    Berglund, Joel
    Linköpings universitet, Institutionen för systemteknik, Kommunikationssystem. Linköpings universitet, Tekniska högskolan.
    Extended LTE Coverage For Indoor Machine Type Communication2013Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The interest of Machine Type Communication (MTC) is increasing and is expected to play an important role in the future network society. In the process of increasing the number of connected devices, the coverage plays an important role. This thesis work aims to study the possibility of supporting coverage limited MTC-devices within LTE by extending the LTE coverage.

    It shows that coverage increase by means of repetition is a good candidate, which allows for a significant increase without hardware upgrades at a low cost in terms of radio resources. For inter-site distances up to 2500 m, the proposed repetition scheme with an increase of 20 dB allows for almost complete coverage where today’s LTE have significant lack of coverage. It also shows that even though the increased coverage implies higher resource usage, the limitation is not in the number of users supported, but rather the coverage at longer inter-site distances.

  • 70.
    Bergqvist, Joakim
    KTH, Tidigare Institutioner, Teleinformatik.
    Dynamic modeling of real-time data sources1996Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This thesis reports on the development and implementation of a method for dynamically generating a state model from the prerecorded trace of a cell-arrival process and the user of this state machine to drive a simulator to evaluate the effects of multiplexing multiple copies of traffic similar to the original trace.

  • 71.
    Bergsaker, Agnethe
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för informatik (IK). Centrum för Informationslogistik.
    Standardsystem och användbarhet: Hur ska man som utvecklare säkra att användbarhet uppnås i små SharePoint-projekt?2014Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    IT (Informationsteknologi) används i dag mycket för att distribuera och förmedla information internt och externt. Ett bra verktyg för informationshantering är verksamhetens intranät. Arbetet handlar om användbarhet i små SharePoint-projekt. Med användbarhet omfattas faktorerna användarvänlighet, anpassning och användaracceptans. Små SharePoint-projekt (på under 300 timmar) innebär att det finns mindre resurser för att tillämpa användbarhet.

    Syftet med detta arbete är att undersöka utvecklare inom SharePoint sina åsikter och förhållningssätt kring användbarhet, samt hur användbarhet bäst kan uppnås i små projekt med begränsade resurser. En kvantitativ metod har används för att genomföra fallstudie av tre utvecklare i ett konsultföretag. Intervjuerna har varit semistrukturerade.

    Resultatet av forskningen drar slutsatsen att användaracceptansen är avgörande för att ett intranät ska uppfattas som användbart för användarna. Användarvänligheten är i standard SharePoint redan relativt definierad och fastställd. Anpassning av ett system istället för att använda inbyggda standarder är ofta kostsamt och resurskrävande. Utvecklarna bör därmed fokusera på utbildning, användarmedverkan, kommunikation och andra faktorer som kan öka acceptansen hos slutanvändarna.

  • 72.
    Berner, Jessica
    et al.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för datavetenskap, fysik och matematik, DFM.
    Wildt-Persson, Andrea
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för datavetenskap, fysik och matematik, DFM.
    Sociala Intranät: Dess användning, möjligheter och risker2011Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    Organizations over the world increasingly start to realize the possibilities of the use of a social intranet, also known as Enterprise 2.0. The social intranets can be used to collaborate and communicate with colleagues in the workplace. Both Cook (2008) and Coope (Barnett, 2011) say that Enterprise 2.0 is about to fundamentally change the way organizations communicate. But do companies know how these tools can be used?

    The study emanates from three questions:

    • How can social intranets be used in business?
    • How can internal communication and collaboration get easier through the use of a social intranet?
    • What are the possible risks with the use of social intranets?

    In this study we have in a qualitative manner been interviewing two companies that currently use social intranets in their daily activities – Securitas and Skåneme-jerier. The interviews where performed via telephone with two people familiar with the respective social intranets. We have also sent out a questionnaire via e-mail to a user group of each company's intranet, to gain knowledge of users' opi-nions.

    The interviews show that both companies agree that it is important for peers to communicate and exchange information and knowledge with each other. The so-cial intranets are used both for communication, collecting employees' knowledge, and to ease the employees information need by gathering all information at the same place. Respondents also pointed out the advantage of written information and knowledge. As it is written it is also searchable. It will also remain in the organiza-tion even though the creator might leave the company. The fact that all users can edit for example wikis and files on the intranet can be used to keep information up to date.

  • 73.
    Bertilsson, Erik
    Linköpings universitet, Institutionen för systemteknik, Datorteknik.
    A Scalable Architecture for Massive MIMO Base Stations Using Distributed Processing2017Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Massive MIMO is an emerging technology for future wireless systems that has received much attention from both academia and industry recently. The most prominent feature of Massive MIMO is that the base station is equiped with a large number of antennas. It is therefore important to create scalable architectures to enable simple deployment in different configurations.

    In this thesis, a distributed architecture for performing the baseband processing in a massive OFDM MU-MIMO system is proposed and analyzed. The proposed architecture is based on connecting several identical nodes in a K-ary tree. It is shown that, depending on the chosen algorithms, all or most computations can be performed in a distrbuted manner. Also, the computational load of each node does not depend on the number of nodes in the tree (except for some timing issues) which implies simple scalability of the system.

    It is shown that it should be enough that each node contains one or two complex multipliers and a few complex adders running at a couple of hundres MHz to support specifications similar to LTE. Additionally the nodes must communicate with each other over links with data rates in the order of some Gbps.

    Finally, a VHDL implementation of the system is proposed. The implementation is parameterized such that a system can be generated from a given specification.

  • 74.
    Bhatia, Nupur
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Policy Management in Context-Aware Networks2007Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The Ambient Network (AN) Project is part of the European Commission’s 6th Framework Programme and aims to enable cooperation between heterogeneous networks, using current and future wireless technologies, minimising the effort of mobile users to gain access to the services that they are interested in - irrespective of their location or the network they are currently using. Because of the highly mobile nature of users and a demand for instant and dynamic access to services, these networks have to be composed ‘on the fly’ without any pre-configurations.

    The use of context information in AN can remove the need for pre-configuration of networks, hence making them autonomic. However, a concern exists that the free and uncontrolled dissemination of context information could breech the privacy of the participants. It is extremely important to address these privacy issues in order to control who has access to what context information. This control can be achieved through the use of well defined policies. This creates a requirement for a framework in the ContextWare architecture for protecting context information.

    This masters thesis project is part of an effort to create a policy based infrastructure for authorisation of access to network context information within the AN. The thesis investigates, models, and designs an architecture for a policy management system based on OASIS XACML, that creates an extension to the architecture for management of context information in the AN. In addition to a policy management architecture within an AN, a policy management architecture for composing ANs is also created. To facilitate the transfer of requests and policies, the thesis creates a Policy Management Protocol. The designed architecture was then implemented to create a proof of concept.

    The designed architecture and protocol were evaluated by running tests on the prototype. The measurements from the tests are analysed and presented in this thesis. The analysis of the experimental data indicates that a policy management system is both feasible and practical. The results show that the delay overhead caused by introducing policy management in a distributed context provisioning system, ranges from 1.7% in a system without load to 6% in a worst case scenario. The throughput of the policy management system is 15 requests per second under load.

  • 75.
    Bhatti, Ayesha
    Linköpings universitet, Institutionen för datavetenskap.
    Snippet Generation for Provenance Workflows2011Independent thesis Advanced level (degree of Master (Two Years)), 30 poäng / 45 hpOppgave
    Abstract [en]

    Scientists often need to know how data was derived in addition to what it is. The detailed tracking of data transformation or provenance allows result reproducibility, knowledge reuse and data analysis. Scientific workflows are increasingly being used to represent provenance as they are capable of recording complicated processes at various levels of detail. In context of knowledge reuse and sharing; search technology is of paramount importance specially considering the huge and ever increasing amount of scientific data. It is computationally hard to produce a single exact answer to the user's query due to sheer volume and complicated structure of provenance.  One solution to this difficult problem is to produce a list of candidate matches and let user select the most relevant result. Here search result presentation becomes very important as the user is required to make the final decision by looking at the workflows in the result list. Presentation of these candidate matches needs to be brief, precise, clear and revealing. This is a challenging task in case of workflows as they contain textual content as well as graphical structure. Current workflow search engines such as Yahoo Pipes! or myExperiment ignore the actual workflow specification and use metadata to create summaries. Workflows which lack metadata do not make good summaries even if they are useful and relevant as search criteria. This work investigates the possibility of creating meaningful and usable summaries or snippets based on structure and specification of workflows. We shall  (1) present relevant published work done regarding snippet building techniques (2) explain how we mapped current techniques to our work (3) describe how we identified techniques from interface design theory in order to make usable graphical interface (4) present implementation of two new algorithms for workflow graph compression and their complexity analysis (5) identify future work in our implementation and outline open research problems in snippet building field.

  • 76.
    Bhide, Priyanka
    Linköpings universitet, Institutionen för systemteknik, Datorteknik.
    Design and Evaluation of Aceelerometer Based Mobile Authentication Techniques2017Independent thesis Advanced level (degree of Master (One Year)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Smartphones’ usages are growing rapidly. Smart phone usages are not limited to the receiving/calling or SMSing anymore. People use smartphone for online shopping, searching various information in the web, bank transactions, games, different applications for different usages etc. Anything is possible by just having a smartphone and the internet. The more usages of the smartphone also increase keeping more secrete information about the user in the phone. The popularity is increasing and so is different ways to steal/hack the phones. There are many areas which require further investigation in the field of smartphone security and authentication.

    This thesis work evaluates the scope of different inbuilt sensors in smartphones for mobile authentication based techniques. The Android Operating system was used in the implementation phase. Android OS has many open source library and Services which have been used for the sensor identification using Java Android platform.

    Two applications using Accelerometer sensor and one using Magnetometer sensor were developed. Two foremost objectives of this thesis work were-1) To figure it out the possibilities of sensor based authentication technique. 2) To check the end user perception/opinion about the applications.

    Usability testing was conducted to gather the user’s assessments/vision of the applications. Two methods which were used for usability testing are named Magical move and Tapping. Users (Most of them) have shown interest and inclination towards tapping application. Although, some users were also expressed inhibitions using both sensor based methods.

  • 77.
    Bildtmark, Kim
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi.
    Jädersand, Robin
    Högskolan i Halmstad, Akademin för informationsteknologi.
    Security Awareness for Mobility: En studie om företagsmobilitet och de säkerhetsrisker som följer2015Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
  • 78.
    Bilien, Johan
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Key Agreement for Secure Voice over IP2003Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This thesis reviews the usual properties and requirements for key agreement protocols. It then focuses on MIKEY, a work-in-progress protocol designed to conduct key agreements for secure multimedia exchanges. The protocol was implemented and incorporated in a SIP user agent - minisip. This implementation was used to measure the additional delay required for key exchange during call establishment. Finally, some schemes are proposed regarding the use of MIKEY in advanced VoIP scenarios, such as conferences and terminal mobility.

  • 79.
    Billman, Johan
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system.
    Hellström, Victor
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system.
    Abusing Keep-Alive Forwarding to flood a VANET: When safety messages become a safety risk2016Independent thesis Basic level (university diploma), 10,5 poäng / 16 hpOppgave
    Abstract [en]

    Cooperative Intelligent Transport Systems (C-ITS) enable vehicles to cooperate with each other and can be used to increase traffic safety and traffic flow. There are several standard initiatives for C-ITS, such as WAVE in the US, ARIB in Japan and ETSI ITS G5 in Europe.

    Decentralized Environment Notification Message (DENM) is a kind of message within ETSI TC ITS. DENMs are event-triggered, multi-hop notification messages that can be for- warded using Keep-Alive Forwarding (KAF).

    In this thesis, KAF is used to flood the network with DENMs sent from a single attack- ing vehicle. Using the simulation tools SUMO, OmNet++ and Veins, a highway scenario is studied. In the scenario, a vehicle sends out a DENM into a network that is being attacked by one other vehicle. Due to how KAF allows messages to be forwarded the other vehicles help flood the network. The results clearly indicate that KAF can be abused to create a Denial of Service (DoS) attack. After just a few seconds, the attack has introduced large de- lays and very high packet loss. The delay to receive a DENM is increased by several orders of magnitude and the packet loss reach unacceptable levels. By getting DENMs several seconds after they are needed, or by not getting them at all, could lead to traffic hazards. 

  • 80.
    Bin, Yang
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab).
    Using Six Sigma Methodology to improve the performance of the Shipment Test2015Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Competition and lead-time pressure motivates us to find new and better ways of continuously improving the output of our work. The emphasis on improvement in both efficiency and quality has become more and more significant in daily activities. The performance of Ericsson’s AXE/APZ products during shipment test phase is one such activity and is the focus of this thesis project. One of the essential principles of shipment testing is to ensure that the test campaigns finish on time. Over the last several decades companies have spent large amounts of time and money on improving test quality and efficiency. Unfortunately, the results have not always been as good as expected. It seems that it is very difficult to improve shipment testing performance using traditional test management methods.

    Motorola introduced Six Sigma in 1986 and achieved 5.4 Sigma level which help them saved 2.2 Billion dollars during the first six years. From Statistic aspect, it means only 3.4 defects per million opportunities. The Six Sigma methodology has been applied as a management philosophy focused on improving efficiency and performance during the shipment test period.

    This thesis gives an introduction to the Six Sigma approach, including the concepts of Six Sigma, its history, development, and methodology. More specifically the author uses the Define, Measure, Analyze, Improve, and Control (DMAIC) approach to evaluate the performance of Ericsson’s AXE/APZ Shipment Testing. This project goal was defined: Compare with the performance of 08AXE shipment test which 87% of test campaigns (2.68 sigma level) were finished on time, 3 sigma level in 09AXE shipment test which means 93%of the test campaigns will be finished on time has to be achieved.  The thesis measured the 08AXE shipment test performance and analyzed the lead time of test campaigns, found the root causes such as poor documents quality from the legacy project, lack of test resources, no system impact analysis. The thesis also provided a set of proposals for improvements and control of the improved process in order to ensure sustainable improved performance results. Finally 93% test campaigns were finished on time in 09AXE and project goal was fulfilled.

  • 81.
    Bjurén, Johan
    Högskolan i Skövde, Institutionen för informationsteknologi.
    USING CASE-BASED REASONING FOR PREDICTING ENERGY USAGE2013Independent thesis Advanced level (degree of Master (Two Years)), 30 poäng / 45 hpOppgave
    Abstract [en]

    In this study, the inability to in a future meet the electricity demand and the urge to change the consumption behavior considered. In a smart grid context there are several possible ways to do this. Means include ways to increase the consumer’s awareness, add energy storages or build smarter homes which can control the appliances. To be able to implement these, indications on how the future consumption will be could be useful. Therefore we look further into how a framework for short-term consumption predictions can be created using electricity consumption data in relation to external factors. To do this a literature study is made to see what kind of methods that are relevant and which qualities is interesting to look at in order to choose a good prediction method. Case Based Reasoning seemed to be able to be suitable method. This method was examined further and built using relational databases. After this the method was tested and evaluated using datasets and evaluation methods CV, MBE and MAPE, which have previously been used in the domain of consumption prediction. The result was compared to the results of the winning methods in the ASHRAE competition. The CBR method was expected to perform better than what it did, and still not as good as the winning methods from the ASHRAE competition. The result showed that the CBR method can be used as a predictor and has potential to make good energy consumption predictions. and there is room for improvement in future studies.

  • 82.
    Björklund, Daniel
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Implementation of a Software-Defined Radio Transceiver on High-Speed Digitizer/Generator SDR142012Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This thesis describes the specification, design and implementation of a software-defined radio system on a two-channel 14-bit digitizer/generator. The multi-stage interpolations and decimations which are required to operate two analog-to-digital converters at 800 megasamples per second (MSps) and two digital-to-analog converters at 1600 MSps from a 25 MSps software-side interface, were designed and implemented. Quadrature processing was used throughout the system, and a combination of fine-tunable low-rate mixers and coarse high-rate mixers were implemented to allow frequency translation across the entire first Nyquist band of the converters. Various reconstruction filter designs for the transmitter side were investigated and a cheap implementation was done through the use of programmable base-band filters and polynomial approximation.

  • 83.
    Björklund, Fredrik
    et al.
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Karlström, Elin
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Enabling Testing of Lateral Active Safety Functions in a Multi-rate Hardware in the Loop Environment2017Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    As the development of vehicles moves towards shorter development time, new ways of verifying the vehicle performance is needed in order to begin the verification process at an earlier stage. A great extent of this development regards active safety, which is a collection name for systems that help both avoid accidents and minimize the effects of a collision, e.g brake assist and steering control systems. Development of these active safety functions requires extensive testing and verification in order to guarantee the performance of the functions in different situations. One way of testing these functions is to include them in a Hardware in the Loop simulation, where the involved hardware from the real vehicle are included in the simulation loop.

    This master thesis investigates the possibility to test lateral active safety functions in a hardware in the loop simulation environment consisting of multiple subsystems working on different frequencies. The subsystems are all dependent of the output from other subsystems, forming an algebraic loop between them. Simulation using multiple hardware and subsystems working on different frequencies introduces latency in the simulation. The effect of the latency is investigated and proposed solutions are presented. In order to enable testing of lateral active safety functions, a steering model which enables the servo motor to steer the vehicle is integrated in the simulation environment and validated.

  • 84.
    Björklund, Ulf
    KTH, Tidigare Institutioner, Teleinformatik.
    Understanding the Performance of the Linux IPv6 Implementation1998Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The new version of the Internet protocol, IP version 6, will eventually replace the current version IP version 4. Before that change can take place the different implementations of IPv6 must be able to perform at least as well as their predecessors, The implementation that is considered here is that of the Linux operating system. All measurements considers native IPv6, e.g. no tunneling in IPv4 packets.

    A small network of two computers was set up on which the performance tests were performed. Throughput and response times were measured on both Ethernet and Fast Ethernet. The conclusions are that IPv6 performs almost as well as IPv4 in both cases. IPv4's slight advantage is due to the fact that it has less overhead on the network since the header is smaller.

    Later a connection to the 6bone is setup. It is run on an ATM network. The performance across that network is also tested.

  • 85.
    Björkman, Anders
    KTH, Tidigare Institutioner, Teleinformatik.
    Configuration of IPv4 Hosts in Zero-Configuration Networks2000Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Zero-configuration networks are networks that require no/zero manual configuration or administration to operate. The essence of a zero-configuration network is that it can be used without having to think about the network at all. The most basic zero-configuration network just provides network communication but more advanced services can be provided as long as no configuration is needed. An important area of use is networks for homes and small businesses. Many of the devices that we have in our homes are or will in a near future be ‘networked’ i.e. capable of network communication. Examples are computers and computer equipment such as printers and scanners, the next generation home-appliances such as the refrigerator and the washing machine, the TV, the stereo, climate sensors etc. etc. The main driving forces for this development are the need for resource sharing e.g. of printers or Internet access, home automation and devices, applications or services that use network communication. Networks for the home must be ‘automatic’ because the average person today has problems programming his VCR and cannot be expected to configure or administrate his/her home-network. Today’s solutions are insufficient because they require manual configuration and some technical knowledge. The market potential is enormous. Almost all homes and most small businesses lack a network infrastructure and many will in a near future acquire it.

    In this thesis I discuss the need and areas of use for zero-configuration networks and I look at how to configure IP hosts in general. Solutions on configuration of hosts in zero-configuration networks are discussed and I propose a solution for IPv4 hosts that enables link-local communication, the most basic type of network communication using IP.

    This master’s thesis was carried out at Ericsson Research in Kista during the fall of 1999 and spring of 2000.

  • 86.
    Björkman Höglund, Matilda
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska högskolan.
    Olsson, Maria
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska högskolan.
    The future of e-commerce2017Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    E-handeln växer eftersom allt fler personer handlar via internet. Konsumtionsmönstret ändras och allt fler söker sig till företags hemsidor för att köpa varor online. Även tjänster som exempelvis musik och film blir mer internetbaserat och köps och beställs ofta via internet. Nu kan nästan vad som helst köpas online, allt från mat till kläder och elektronik. E-handeln är ett smidigare och ibland billigare komplement till den traditionella handeln. Detta underlättar för kunderna och kan frigöra mer tid till de personer som e-handlar. Med den ökade e-handeln uppstår det också problem. Det behövs bra distributionsupplägg som kan ta hand om alla varor som ska transporteras. Den ökade e-handeln innebär fler transporter i städerna. Om e-handeln fortsätter att öka och det blir ännu fler transporter, vilka konsekvenser får det? Vilka olika distributionsupplägg kommer det att finnas i framtiden för att kunna leverera varor till kunderna på ett effektivt sätt? I det här examensarbetet har klädbranschen och dess e-handel undersökts. Det som har studerats, är hur branschen påverkar transporterna kopplat till e-handeln. Intervjuer med olika företag har genomförts i examensarbetet för att få en överblick över hur deras e-handel har utvecklats över tid samt hur de tror att e-handeln kommer att se ut i framtiden. Intervjuer med teoretiker som arbetar med citylogistik har även gjorts, för att få information hur de tror e-handeln kommer påverka transporterna kopplat till e-handeln. I framtiden kommer det troligtvis inte användas några nya distributionsupplägg, utan de som redan finns kommer bli mer utvecklade. De distributionsupplägg som finns idag är att kunderna hämtar sina varor via ett ombud, i en butik/lagerlokal, paketombud eller att varorna skickas hem till kunden. I framtiden kan det bli allt vanligare med hemleverans och att kunderna eventuellt kommer att få styra sina leveranser mer än vad som är möjligt idag. För att se konsekvenserna av transporterna kopplat till e-handeln presenteras två olika fall. Dessa två fall delas upp i åtta olika scenarier. Dessa scenarier är uppbyggda efter olika antaganden om vilka transportmedel som används och i vilken utsträckning. Det scenario som gav lägst koldioxidutsläpp och lägst fordonskilometer var det scenario där 100 % av godset levereras till ett utlämningsställe via en samlastningscentral utan att kunderna använder sin personbil mer. En förändrad volym av e-handel ger olika konsekvenser på transporterna, beroende på vilken typ av distributionsupplägg som används och vilket transportmedel som utnyttjas, samt vilken systemavgränsning som görs. Generellt sett tyder det på att antalet transportkilometer kopplat till e-handeln kommer att öka i framtiden. Vad gäller koldioxidutsläppen är det svårare att göra en bedömning, beroende på vilka transportmedel som kommer att användas i framtiden men också på den tekniska utvecklingen av dessa. Även om antalet fordonskilometer ökar kan effektivare transporter leda till minskade koldioxidutsläpp.

  • 87.
    Blank, Bruno
    et al.
    KTH, Tidigare Institutioner, Teleinformatik.
    Häggström, Mattias
    KTH, Tidigare Institutioner, Teleinformatik.
    Mobile Communication In a Multiple Device Environment1998Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    It is nowadays common that users have more than one computer. At the office, a stationary computer or possibly a laptop is used. When travelling, a Personal Digital Assistant is better suited for e-mail, address book, and scheduling. Probably the user also has an advanced mobile phone. A problem for many users is it has traditionally been quite complex to handle having multiple computers, since the support for mobile use has been insufficient.

    We have looked into common scenarios for mobile users and given and overview of related products and technologies. Some of the traditional protocols for e-mail have been reviewed. We have listed problems with those and suggested improvements. Sendit has a proprietary protocol, which we have compared to traditional protocols.

    This report gives an overview from the user’s point of view. From what we have seen, there are lots of upcoming technologies and solutions to assist mobile users. However, many problems still remain and need to be solved to facilitate the mobile user’s situation.

  • 88.
    Blomberg, Patrik
    KTH, Tidigare Institutioner, Teleinformatik.
    Construction and Implementation of a Walkstation Mobile-distributed File System Testbed1995Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    In this Master's Thesis an investigation, design and implementation of an object-oriented prototype of a new kind of client-agent-server based distributed file system, suited for wireless mobile computing, are presented. An overview is given of the characteristics and the inherent problems of mobile-wireless computing. Some solutions and techniques to reduce the effects of these problems are described. A presentation of a project (the Walkstation project) that tries to solve these problems is also given. Software to support a mobile-distributed file system is designed and implemented. Various software development techniques and mobile file system design solutions are proposed, and used in the implementation. An integrated caching and prefetching scheme with dynamically loadable cache and prefetch manager objects is designed and implemented. It is proposed that different cache and prefetch algorithms should be used for different kinds of network links. A cache/prefetch-manager object architecture with automatically location-dependant dynamical swapping of network specific manager objects at run-time is therefore proposed and implemented. A mechanism is designed with which an application optionally can be mobility-aware by subscribing for network-change events. Finally, an expedient example of a methodology to achieve easy-understandable and well-designed code, and good extensibility possibilities is explained and used in the development. This is done by utilizing an object-oriented software development methodology in the entire software development cycle.

  • 89.
    Bodinger, Ronnie
    KTH, Tidigare Institutioner, Teleinformatik.
    An MPLS Connection Manager for an Edge Router1998Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The Internet has been growing rapidly over the last couple of years. The increasing demand for network bandwidth is becoming a huge problem. To solve this problem, new methods must be developed. Ericsson’s solution is the use of MultiProtocol Label Switching (MPLS). MPLS has the potential to have a major impact on IP networking. It has the simplicity and dynamic nature of an IP network, but retains the performance of an ATM network. Furthermore, from an administrator’s point of view, MPLS will drastically simplify network management.

    The key principle behind MPLS is to be able to forward by switching packets through a network instead of routing packets. In order to do this, paths are established at the data link layer throughout the MPLS network. A fixed length identifier known as “label” identifies each path. Then the packets are simply forwarded on the path using layer two switching, instead of performing layer three routing.

    By using MPLS, performance is increased and it provides a good basis for traffic engineering, Quality of Service (QoS) guarantees, and Virtual Private Networks (VPN).

    I have implemented an MPLS ATM driver for an Ericsson AXI 510 Edge Router. The driver is responsible for converting generic MPLS labels into standard ATM labels (VPI/VCI). The driver also modifies the forwarding process in the router so that ATM paths are used to forward the packets, instead of the conventional forwarding methods. This implementation has been partly tested and it complies with MPLS current Internet drafts so far.

  • 90.
    Borgström, Kristofer
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Multimedia Messaging Service Components for Web 2.02008Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The purpose of this master’s thesis is to simplify the exchange (in both directions) of multimedia content between mobile phones and network attached web servers. The solution proposed in this report specifically concerns displaying Multimedia Messaging Service (MMS) messages via a web browser connected to a network-attached web server and graphically authoring MMS messages via a web interface.

    This thesis project is important because it brings multimedia content, in the form of MMS messages, from isolation in the telecommunication world closer to wide availability via the Internet. This transition is very important as the Internet is where media is shared with the world today. This approach brings added value to end users who want to share content generated using their phone on a web site. It also provides added value to operators who want to increase the amount of MMS traffic in their networks.

    The solution is non-trivial because there are a number of complexities at both ends. This is because the MMS messages that are authored at mobile phones differ between both handset models and manufacturers. Moreover, the format used for MMS (MMS SMIL) is not widely used on the Internet, thus a transformation to an Internet browser supported format must be performed. The thesis examines to what extent this transformation can be completely automatic and how MMS messages can be authored through a web interface.

    The results show that MMS messages can be successfully transformed to HTML and embedded directly in web pages, thus providing a seamless experience for viewing MMS messages. Depending on the content of the MMS message in question, the current browser and which media player plug-ins are available, the generated HTML will be displayed differently. The results also show that MMS messages can be composed in real time* through a web interface with good results.

  • 91.
    Borgviken, Jonathan
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi.
    Johansson, Carl
    Högskolan i Halmstad, Akademin för informationsteknologi.
    Industrial Wireless IPv6 Sensor device2017Independent thesis Basic level (university diploma), 10 poäng / 15 hpOppgave
  • 92.
    Borison, Torbjorn
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Object Synchronization and Security for Mobile Communications Devices2001Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The main objective of this master’s thesis project was to investigate and find solutions to the problem of how to combine the SyncML synchronisation specification with object security and thus protection of personal information, such as contacts and calendar entries in mobile devices.

    SyncML is a new synchronisation specification agreed upon by major device developers (Ericsson, Palm, Motorola, etc.) and the major synchronisation server developers (Starfish, Puma, fusionOne, etc.). It is independent of transport (HTTP, WSP, or OBEX) platform, operating system, and application and simplifies synchronisation of personal information between dissimilar SyncML supportive devices.

    SyncML compliant devices are fully capable of synchronising information with a third party operated Internet based server and a desktop computer. This allows us to access, up-date and maintain information independent of Intranets or geographical position. However, synchronising and storing confidential personal information on an third party operated Internet based server entails weaknesses in our personal information security. Even if transport and storage security are used, how secure is the server where this information is stored since this server has the highest probability of being attacked. Can we really trust that an employee or other person with valid appropriated administrators access to the storage facility with the appropriate knowledge, working together with the third party server operator, won’t try to access our stored information? To prevent this, the personal information’s confidentiality must be guaranteed before the information leaves the device.

    When synchronising and exchanging personal information, the information is often marked according to a specific format. The three de-facto standard PIM formats are: (1) vCard (contact information), (2) vCalendar, and (3) iCalendar (calendar and scheduling information). These formats divide the personal information into properties. Each property is assigned to contain a small piece of the personal information entry (e.g. a telephone number, an e-mail address, the time when the calendar event begins, etc.).

    Furthermore to preserve the interoperability between different devices given by SyncML, authorised recipients must automatically be able to reverse the encryption process and decrypt the encrypted property value. Therefore general cryptographic formats are used (e.g. CMS, PGP and the newly developed XML Encryption). They add information needed by the recipients (e.g. algorithm used, padding method used on the plain text, etc.), encrypt the plaintext into cipher text, and decrypt the cipher text into plain text given the correct key.

  • 93.
    Boström, Tomas
    et al.
    KTH, Tidigare Institutioner, Teleinformatik.
    Lindroos, Olle
    KTH, Tidigare Institutioner, Teleinformatik.
    Hellström, Lennart
    KTH, Tidigare Institutioner, Teleinformatik.
    Simple Mobile IP1999Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This thesis describes an implementation and evaluation of an IP mobility management protocol, Simple Mobile IP. The protocol enables dynamic address allocation and configuration of mobile terminals through utilisation of DHCP.

    Simple Mobile IP provides IP mobility within one administrative domain, in contrast to the global mobility in conventional Mobile IP. Both protocols use IP tunnelling but in Simple Mobile IP the tunnel runs along the optimised route, thus avoiding triangular routing.

    The protocol was implemented on the Linux platform and evaluated in a wireless LAN environment. The solution detects subnet transitions at the link layer, resulting in loss of IP connectivity for approximately 100 ms when mobile terminals move between subnets. The overhead, introduced by IP tunnelling, reduces the throughput by 3.8% in a wireless LAN environment.

  • 94.
    Bratel, Daniel
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Industriell teknik.
    Bernestrå, Christopher
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Industriell teknik.
    Internet of Things i Hyresfastigheter: Förutsättningar för implementering av ny teknik2016Independent thesis Advanced level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [en]

    The purpose of this report is to review the current conditions exsisting for the implementation of Internet of Things in apartment buildings and how insight can be accomplished for these conditions in real estate companies. Internet of Things is a technology which has increased in popularity in later years and builds on objects connecting to each other or the internet. In conjunction with the reduction of implementation costs for the technology and the increase of possible applications, an interest has grown in many different business sectors. This study concerns the real estate company FinaHem, where the conditions for measurement of different values using connected sensors is analyzed. To answer the formulated questions regarding technological efficiency, financial factors and how a potential solution using Internet of Things would be recieved by tenants, this paper is designed as a case study. The case study evaluates the operations of FinaHem and utilizes both qualitative and quantitative methods, as well as a business case method. The result and the analysis from the study indicates important factors for the company’s conditions to implement Internet of Things. Technological solutions regarding energy savings, detections of water damage, and visualisation has exhibited business value. Furthermore, the importance of evaluating opinions from residents, and creating a positive experience for them, is established.

  • 95.
    Brejcha, Mikael
    KTH, Tidigare Institutioner, Teleinformatik. KTH, Skolan för informations- och kommunikationsteknik (ICT).
    Talaria: A Distributed Architecture for Supporting Monitoring and Collaborative Information Retrieval1999Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

     As the amount of information available via the Internet continues to explode, new means of finding and keeping oneself updated on sources of information must be found. This report presents a system that monitors sources of information on behalf of a user and also introduces new sources of information that potentially could be of interest to the user. As monitored information updates it can be directed to a variety of different displaying devices, ranging from simple pagers to advanced desktop computers. Ideas behind the design of the architecture are explained. The report explains why the system will scale as the number of users increases. The report describes measures taken to ensure user privacy.

  • 96.
    Bremstedt Pedersen, Ivan
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Andersson, Alfred
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    More than downloading: Visualization of data produced by sensors in a home environment2012Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    A home automation system usually contains a set of tools that users use to control devices in their homes, often remotely. These devices often include but are not limited to light switches, thermostats, thermometers, window blinds, and climate controls. The potential for these kinds of systems is huge because of the sheer number of devices that could be controlled and managed with minimal and inexpensive extra hardware. Many of the appliances in a normal home could benefit from being connected to a system that allows the owner to manage and control the devices in their home. Thus the number of potential devices is orders of magnitude larger than the number of homes connected to the system. There are several systems on the market that provide systems to monitor and control a home environment, however these systems only support specific in system devices. This uncovers a problem where a homeowner only has the opportunity to use specific products that fit into these systems. By introducing an open platform for the public that are not bound to any system we can allow more devices to be integrated in the home and contribute to further development of smarter homes.

    The goal with this project was to provide a scalable open platform with the possibility of asynchronous updating. This has been done by implementing multiple logical parts to both provide a web interface for the user and to allow us to handle communication and storage of data. All these parts are linked together to form a system of servers that handles all background operations. This thesis discusses and presents implementations of all of these servers, how they are implemented, communicate with each other, provide secure connections and how they can scale with increasing usage. In this process we also discuss and present techniques that were used, how to use them and their benefits, to help us reach our goal.

  • 97.
    Broman, Fredrik
    et al.
    KTH, Tidigare Institutioner, Teleinformatik.
    Tarberg, Fredrik
    KTH, Tidigare Institutioner, Teleinformatik.
    Implementation andAnalyses of theMobile-IP Protocol1996Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This report is the result of a masters degree project conducted at the Department of Teleinformatics at the Royal Institute of Technology during the autumn 1995. The area investigated is the Mobile Internet Protocol, especially its implementation and efficiency.

    The thesis work is divided into three areas. The first area includes the development and implementation of a Management Information Base for the Mobile-IP protocol. The second area deals with the porting of a Mobile-IP implementation for SunOS to MachOS and Solaris. The last area covers the tests done to measure the throughput and latency of the protocol.

  • 98.
    Broms, Daniel
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Access restrictions in surrogates using Portable Channel Representation2002Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This Master thesis investigates how content with access restrictions can be handled in a Content Distribution Network (CDN). The thesis focuses on CDNs where the distribution is made using Portable Channel Representation (PCR), a description of content that enables installation on any platform. There has been a demand from customers for access restriction support when distributing web sites. Ranging from personal homepages wanting to restrict access using some simple password authentication protocol to corporate websites wanting HTTPS support.

    This thesis starts with a survey of available authentication mechanisms as well as available publication protocols with support for protection. This provided the basis for the design of the new protection element for PCR spanning most protection requirements. The PCR model is realized using XML in the Lokomo Software Suite. The new design has been implemented in the context of the Lokomo Software Suite. The protection has been shown to correctly install basic authentication on both Apache’s HTTP Server and Microsoft’s Internet Information Server.

  • 99.
    Brundin, Peter
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    LESpy - PCM Link Analyzer2002Independent thesis Advanced level (degree of Master (Two Years)), 10 poäng / 15 hpOppgave
    Abstract [en]

    This report will discuss the design of a test tool, a PCM link analyzer, LESpy. The development of LESpy is based upon reuse of C++ source code from previous test equipment from INEO, LESim. The purpose of LESpy is a tool for analyzing two telephony interfaces in Ericsson’s ”Radio in the Local Loop” system RAS 1000. Monitoring the Channel Associated Signaling (CAS) interface was the primary goal. As second goal was to find a solution to analyze the ISDN interface.

    The report presents some background information about telephony, computer telephony, the RAS 1000 system, and the development and target environment (IBM’s operating system OS/2). It also describes building blocks and functionality, i.e. the nodes, components, classes, and use cases of LESpy through UML diagrams.

    The result of the project is a test tool where most of the requirements were fulfilled through inheritance of new classes and new functionality by polymorphism. As required supervision and address signaling could be monitored and saved to a file.

  • 100.
    Bude, Cristian
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab).
    Kervefors Bergstrand, Andreas
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab).
    Internet of Things: Exploring and Securing a Future Concept2015Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    Internet of Things (IoT) is a concept that encompasses various objects and methods of communication to exchange information. Today IoT is more a descriptive term of a vision that everything should be connected to the internet. IoT will be fundamental in the future because the concept opens up opportunities for new services and new innovations. All objects will be connected and able to communicate with each other, while they operate in unprotected environments. This later aspect leads to major security challenges.

    Today, IoT is in great need of standardization and clear architectures that describe how this technology should be implemented and how IoT devices interact with each other in a secure manner. The security challenges are rooted in the technology and how information is acquired and manipulated by this technology. This thesis provides an introduction to what the IoT is and how it can be used as well as some of the threats that IoT may face in regards to information security. In addition, the thesis provides the reader with some suggestions about how to potentially solve the fundamental need for authentication and secure communications. The solutions presented are based on both contemporary solutions and technologies that are under development for the future. Contemporary solutions are based on security protocols such as IPSec and DTLS. These protocols are being used in an environment that extends across the Internet and into a 6LoWPAN network. The proposed authentication solution has been developed based on a public key infrastructure and trust models for certificate management.

    As future work, the thesis presents several research areas where this thesis can be used as a basis. These specialization areas include further analysis of vulnerabilities and an implementation of the proposed solutions.

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