A Mobile ad hoc network is a collection of wireless nodes that dynamically organize themselves to form a network without the need for any fixed infrastructure or centralized administration. The network topology dynamically changes frequently in an unpredictable manner since nodes are free to move. Support for multicasting is essential in such environment as it is considered to be an efficient way to deliver information from source nodes to many client nodes. A problem with multicast routing algorithms is their efficiency as their forwarding structure determines the overall network resource consumption makes them significantly less efficient than unicast routing algorithms. In this research, we improve the performance of the popular ODMRP multicast routing protocol by restricting the domain of join query packets, which have been lost. This is achieved by augmenting the join query packets with minimum extra information (one field), which denotes the number of the visited node from previous forwarding group. Simulation results show, that our mechanisms significantly reduce the control traffic and thus the overall latency and power consumption in the network.

Multipath TCP (MPTCP) is an extension to traditionalTCP that enables a number of performance advantages,which were not offered before. While the protocol specificationis close to being finalized, there still remain some concernsregarding deployability and security. This paper describes theon going work to develop a solution that will facilitate thedeployment of MPTCP. The solution will not only allow non-MPTCP capable end-hosts to benefit from MPTCP performancegains, but also help ease the network security concerns that manymiddleboxes face due to the possibility of data stream beingfragmented across multiple subflows.

This deliverable provides a description of the framework identified for the collaborative activities between different partners in the context of NEWCOM department 7 on QoS provision in heterogeneous wireless networks. The considered models, assumptions and expected results are pointed out for each activity. The deliverable also includes a report on the means to achieve the integration between the different partners

This deliverable constitutes the final report of all the activities that carried out in the framework of the NEWCOM department 7. It contains a description of the main technical achievements for each one of the activities in which the department has been organised togehter with the list of indicators reflecting the degree of integration that has been achieved among the different partners

Information-centric networking (ICN) with its design around named-based forwarding and in-network caching holds great promises to become a key architecture for the future Internet. Still, despite its attractiveness, there are many open questions that need to be answered before wireless ICN becomes a reality, not least about its congestion control: Many of the proposed hop-by-hop congestion control schemes assume a fixed and known link capacity, something that rarely – if ever – holds true for wireless links. As a first step, this paper demonstrates that although these congestion control schemes are able to fairly well utilise the available wireless link capacity, they greatly fail to keep the link delay down. In fact, they essentially offer the same link delay as in the case with no hop-by-hop, only end- to-end, congestion control. Secondly, the paper shows that by complementing these congestion control schemes with an easy- to-implement, packet-train link estimator, we reduce the link delay to a level significantly lower than what is obtained with only end-to-end congestion control, while still being able to keep the link utilisation at a high level. 

Communication by wireless technologies has seen a tremendous growth in the last decades. Mobile phone technology and wireless broadband solutions are rapidly replacing the last-hop wireline connectivity for telephones and Internet access.  Research has, however, shown that Internet traffic can experience a performance degradation over wireless compared to wired networks.  The inherent properties of radio communication lead to a higher degree of unreliability, compared to communication by wire or fiber.  This can result in an increased amount of transmission errors, packet loss, delay and delay variations, which in turn affect the performance of the main Internet transport protocols TCP and UDP.  This dissertation examines the cross-layer relationship between wireless transmission and the resulting performance on the transport layer. To this end, experimental evaluations of TCP and UDP over a wireless 4G downlink system proposal are performed.  The experiment results show, in a holistic scenario, that link-level adaptive modulation, channel prediction, fast persistent link retransmissions, and channel scheduling, enables the transport protocols TCP and UDP to perform well and utilize the wireless link efficiently.  Further, a novel approach is proposed where a modified TCP receiver can choose to accept packets that are corrupted by bit errors. Results from network emulation experiments indicate that by accepting and acknowledging even small amounts of corrupted data, a much higher throughput can be maintained compared to standard TCP.

This paper presents a wireless link and networkemulator, based upon the "Wireless IP" 4G system proposalfrom Uppsala University and partners. In wireless fading down-links (base to terminals) link-level frames are scheduled andthe transmission is adapted on a fast time scale. With fastlink adaptation and fast link level retransmission, the fading properties of wireless links can to a large extent be counteractedat the physical and link layers. A purpose of the emulatoris to investigate the resulting interaction with transport layer protocols. The emulator is built on Internet technologies, andis installed as a gateway between communicating hosts. The paper gives an overview of the emulator design, and presentspreliminary experiments with three different TCP variants. The results illustrate the functionality of the emulator by showing theeffect of changing link layer parameters on the different TCP variants.

This paper presents results from an experimental study of TCP in a wireless 4G evaluation system. Test-bed results on transport layer performance are presented and analyzed in relation to several link layer aspects. The aspects investigated are the impact of channel prediction errors, channel scheduling, delay, and adaptive modulation switch level, on TCP performance. The paper contributes a cross-layer analysis of the interaction between symbol modulation levels, different scheduling strategies, channel prediction errors and the resulting frame retransmissions effect on TCP. The paper also shows that highly persistent ARQ with fast link retransmissions do not interact negatively with the TCP retransmission timer even for short round trip delays.

This paper presents a wireless link and network emulator,along with experiments and validation against the "Wireless IP" 4G system proposal from Uppsala University and partners. In wireless fading downlinks (base to terminals) link-level frames are scheduled and the transmission is adapted on a fast time scale. With fast link adaptation and fast link level retransmission, the fading properties of wireless links can to a large extent be counteracted at thephysical and link layers. The emulator has been used to experimentally investigate the resulting interaction between the transport layer and the link layer. The paper gives an overview of the emulator design, and presents experimental results with three different TCP variants in combination with various link layer characteristics.

The performance of applications in wireless networks is partly dependent upon the link configuration. Link characteristics varies with frame retransmission persistency, link frame retransmission delay, adaptive modulation strategies, coding, and more. The link configuration and channel conditions can lead to packet loss, delay and delay variations, which impact different applications in different ways. A bulk transfer application may tolerate delays to a large extent, while packet loss is undesirable. On the other hand, real-time interactive applications are sensitive to delay and delay variations, but may tolerate packet loss to a certain extent. This paper contributes a study of the effect of link frame retransmission persistency and delay on packet loss and latency for real-time interactive applications. The results indicate that a reliable retransmission mechanism with fast link retransmissions in the range of 2-8 ms is sufficient to provide an upper delay bound of 50 ms over the wireless link, which is well within the delay budget of voice over IP applications.

This paper presents a wireless link and network emulator for the "Wireless IP" 4G system proposal from Uppsala University and partners. In wireless fading downlinks (base to terminals) link-level frames are scheduled and the transmission is adapted on a fast time scale. With fast link adaptation and fast link level retransmission, the fading properties of wireless links can to a large extent be counteracted at the physical and link layers. The emulator has been used to experimentally investigate the resulting interaction between the transport layer and the physical/link layer in such a downlink. The paper introduces the Wireless IP system, describes the emulator design and implementation, and presents experimental results with TCP in combination with various physical/link layer parameters. The impact of link layer ARQ persistency, adaptive modulation, prediction errors and simple scheduling are all considered.

Future network environments will be heterogeneous and mobile terminals will have the opportunity to dynamically select among many different access technologies. Therefore, it is important to provide service continuity in case of vertical handovers when terminals change the access technology. Two important wireless access technologies are WLAN (Wireless Local Access Networks) and WMAN (Wireless Metropolitan Access Networks) networks. In this paper, we address several challenges related to a seamless integration of those technologies. We highlight important aspects for designing a WLAN/WMAN interworking architecture and we address important Quality of Service (QoS) issues for such interworked systems like degree of QoS support provided by the technologies, QoS mapping and signalling for vertical handover. By formulating several interworking scenarios, where WLAN users with ongoing voice, video and data sessions hand over to WMAN, we study QoS and performance issues and analyse feasibility of seamless session continuity through simulations

This document proposes a new mechanism for TCP and SCTP that can be used to recover lost segments when a connection's congestion window is small. The "Early Retransmit" mechanism allows the transport to reduce, in certain special circumstances, the number of duplicate acknowledgments required to trigger a fast retransmission. This allows the transport to use fast retransmit to recover packet losses that would otherwise require a lengthy retransmission timeout.

Research at universities is today often conducted as projects. This is especially true in the engineering, natural science, medicine, and social science disciplines. Research projects are typically carried out by different categories of employers, such as professors, associate professors, assistant professors, and PhD students. These projects are typically managed by the person that applied for the project money, or the person that is the most experienced researcher at the department, which is often a professor or associate professor. From such leading persons, miracles are expected. Except acting as project managers, they are also engaged in many other parallel activities, e.g., supervision of PhD students, undergraduate and graduate education, conference organization and administration, project application writing, and representing the department internally as well as externally.



In this report, a survey of project management competence within research projects at Karlstad University is presented. Empirical data have been gathered through two questionnaires and six complementary interviews. Professors and associate professors as well as PhD students have participated in the study. The survey shows that the active project managers have learned to lead projects based on experience and very few project managers have a formal leadership education. This implies that long established project management methods and tools are seldom used.



Based on the outcome from the survey and our own observations, four concrete activities to improve project management skills are proposed in the report. The first activity is to provide a suitable and well-balanced course in project management methods that is offered to both active and future project managers. The second activity is to establish experience networks among active project mangers at Karlstad University. The third activity is to create a mentor program for new project managers. The fourth activity is to establish a group of experienced project managers that can assist in and give support to ongoing and planned projects.

The mobile Internet is a fast growing technology that introduces new privacy risks. We argue that, since privacy legislation alone is not sufficient to protect the users privacy, technical solutions to enhanceinformational privacy of individuals are also needed. This paper introduces mCrowds, a privacy-enhancing technology that combines the concept of a crowd system in a mobile Internet setting with a filteringfunctionality to enable anonymity towards the content providers

This paper takes a theoretical as well as a practical approach to what IPv6 is in order to create an understanding for the new protocol. In addition to the theoretical review of the protocol, this paper also describes the work that has been done in order to create an implementation that is supposed to bring  secure IPv6 support to both private individuals and smaller organizations, even if the Internet service provider only offers IPv4.

This paper and implementation is done on a personal initiative, since the need for knowledge regarding IPv6 is rapidly increasing and private individuals probably will be among the last to be offered native IPv6 support from their Internet service providers.

Properties and behavior of cellular automata are considered. Cellular automata can simply be described as lattices of cells, where the cells can be in a finite number of states. By using simple rules the states of the cells are updated at discrete time steps. The evolution of cellular automata can be used for computations. Some cellular automata display universality meaning that there is no limit to the sophistication of the computations they can perform.

In this paper properties and behavior of cellular automata are considered. Cellular automata can simply be described as lattices of cells, where the cells can be in a finite number of states. By using simple rules the states of the cells are updated in parallel at discrete time steps. Depending on the rule and, to a certain degree, the initial states of the cells, the evolution of a cellular automaton is restricted to a small number a ways. Some cellular automata evolve uniformly, meaning that all cells end up in the same state, while others evolve randomly, meaning that the states of the cells appear to be totally randomized during evolution. Intermediate behavior, displaying repetitiveness or nesting, also occurs.Properties of cellular automata that are discussed in the paper are, for instance, sensitivity to initial conditions, randomness, reversibility, entropy, and conservation. These properties also appear in the physical world and cellular automata provide good examples in the understanding of these properties.The evolution of cellular automata can be used for computations. Some cellular automata even display the property of universality, a term well known from the universal Turing machine, meaning that there is no limit to the sophistication of the computations they can perform.

Cellular automata have a widespread use in the description of complex phenomena in disciplines as disparate as for example physics and economics. They are described by a lattice of cells, states of the cells, and rules for updating the states of the cells. One characteristics of a cellular automaton is the simplicity of the rules that determine how the cellular automaton evolves in time. These rules are local, are applied in parallel to all the cells and despite their simplicity they may give rise to a complex macroscopic behaviour. In this paper this is illustrated by examples from hydrodynamics and it is shown that cellular automata might provide powerful alternatives to partial differential equations

Cellular automata have a widespread use in the description of complex phenomena in disciplines as disparate as, for example, physics and economics. A cellular automaton is a lattice of cells, and the cells can be in a finite number of states. By using simple local rules the states of the cells are updated in parallel at discrete time steps. In short, a cellular automaton can be characterised by the three words - simple, local, and parallel. These three words are one of the reasons for the attractiveness of cellular automata. They are simple to implement and they are well suited for parallel computers (computations). Another reason for using cellular automata are for their spatio-temporal properties. The lattice may represent space and the updating of the cells gives a

dimension of time.



In spite of the simplicity of cellular automata they may give rise to a complex macroscopic behaviour. This is illustrated, in this thesis, by an hydrodynamic example, namely the creation of vortices in flow behind a cylinder.



Although cellular automata have the ability to describe complex phenomena it is sometimes hard to find the proper rules for a given macroscopic behaviour. One approach which has been successfully employed is to let cellular automata rules evolve (for example, through genetic algorithms) when finding the desired properties. In this thesis this is demonstrated for two-dimensional cellular automata with two possible states of the cells. A genetic algorithm is used to find rules that evolve a given initial configuration of the cells to another given configuration.

The aim of the thesis is to analyze a method which describes the electron correlation in atoms and molecules. The method is based on Rayleigh-Schrödinger perturbation theory with a partitioning of the Hamiltonian into a fairly simple zeroth-order operator and a perturbation operator. The zeroth-order Hamiltonian is founded on a one-electron Fock-type operator and two different operators have been tested. The zeroth-order wave function is constructed from a complete active space self-consistent field (CASSCF) calculation. This means that the zeroth-order wave function for open-shell systems and systems with strong configurational mixing (near degeneracy) can be obtained on an equal level as closed-shell (single determinant) states. The theory is formulated in such a way that the Möller-Plesset perturbation theory is obtained for the closed-shell (single determinant) state. The flexibility of the CASSCF method makes it possible, in principle, to construct the zeroth-order wave function (and the zeroth-order Hamiltonian) to any desired accuracy. The perturbation expansion of the energy is therefore expected to converge fast and only up to the second-order contribution has been implemented leading to fairly fast and accurate calculations. The aim of the computer implementation is to describe the electron correlation in small and medium-sized molecules (up to 20 atoms) accurately. The application of the perturbation method to a number of problems in chemistry is demonstrated in the thesis: (1) the calculation of electronic properties and harmonic vibrational frequencies of the ozone molecule; (2) the calculation of electric dipole polarizabilities of excited valence states of several first- and second-row atoms; (3) the calculation of excited states of the nickel atom, the benzene molecule, and the azabenzenes pyridine, pyrazine, pyridazine, and s-triazine

The electronic spectrum of VCr has been studied using the complete-active-space self-consistent field complete-active-space second-order perturbation theory approach. Potential energy curves for 12 electronic states have been computed. Transition energies, with respect to the X^2Delta ground state, for some of the calculated electronic states are (with possible experimental values within parentheses): 0.53 eV (0.56) for A^2Sigma+, 1.03 eV (1.14) for A^4Delta, 1.20 eV (1.14) for B^2Delta, 1.45 eV (1.51) for B^4Delta, 1.60 eV (1.51, 1.78) for C^2Delta, and 1.61 eV (1.63) for A^4Sigma^-.

The PrimeLife Policy Language (PPL) has the objective of helping end users make the data handling practices of data controllers more transparent, allowing them to make well-informed decisions about the release of personal data in exchange for services. In this chapter, we present our work on user interfaces for the PPL policy engine, which aims at displaying the core elements of a data controller's privacy policy in an easily understandable way as well as displaying how far it corresponds with the user's privacy preferences. We also show how privacy preference management can be simplified for end users.

This paper discusses the approach taken within the PrimeLife project for providing user-friendly privacy policy interfaces for the PrimeLife Policy Language (PPL).We present the requirements, design process and usability testing of the “Send Data?” prototype, a browser extension designed and developed to deal with the powerful features provided by PPL. Our interface introduces the novel features of “on the fly” privacy management, predefined levels of privacy settings, and simplified selectionof anonymous credentials. Results from usability tests showed that users understand and appreciate these features and perceive them as being privacy-friendly, and they are therefore suggested as a good approach towards usable privacy policy display and management. Additionally, we present our lessons learnt in the design process of privacy policy interfaces.

We present a prototype of the user interface of a transparency tool that displays an overview of a user's data disclosures to different online service providers and allows them to access data collected about them stored at the services' sides. We explore one particular type of visualization method consisting of tracing lines that connect a user's disclosed personal attributes to the service to which these attributes have been disclosed. We report on the ongoing iterative process of design of such visualization, the challenges encountered and the possibilities for future improvements.

In the last decade, we have seen an explosive growth in the deployment of multimedia applications on the Internet. However, the transport service provided over the Internet is not always feasible for these applications, since the network was originally designed for other types of applications. One way to better accommodate the service requirements of some of these applications is to provide a partially reliable transport service. A partially reliable transport service does not insist on recovering all, but just some of the packet losses, thus providing a lower transport delay than a reliable transport service. The work in this thesis focuses on the design, implementation, and evaluation of a partially reliable transport protocol called PRTP. PRTP has been designed as an extension to TCP in order to show that such a service could be effectively integrated with current protocol standards. An important feature of

PRTP is that all modifications for PRTP are restricted to the receiver side, which means that it could be very easily deployed. The thesis presents performance results from various experiments on a Linux implementation of PRTP. The results suggest that transfer times can be decreased significantly when using PRTP as opposed to TCP in networks in which packet loss occurs. Furthermore, the thesis includes a study that investigates how users perceive an application that is based on a partially reliable service. Specifically, how users select the trade-off between image quality and latency when they download Web pages is explored. The results indicate that many of the users in the study could accept less than perfect image quality if the latency could be shortened.

The ongoing deployment of applications that transmit multimedia data makes it important for the Internet to better accommodate the service requirements of this type of applications. One approach is to provide a partially reliable service, i.e. a service that does not insist on recovering all but only some of the packet losses, thus providing less delay than a reliable transport service. This technical report describes a transport protocol that provides a partially reliable service. The protocol, called PRTP, is especially aimed at applications with soft real-time requirements. The report also presents performance results from a number of different experiments investigating different aspects of PRTP. The results indicate that transfer times can be significantly decreased when using PRTP as opposed to TCP when packets are lost in the network.