Browsing by Author "Manner, Jukka, Prof., Aalto University, Department of Communications and Networking , Finland"

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    Engaging a Moving Organisation - Modelling a military enterprise with architecture tools
    (Aalto University, 2020) Mattila, Juha Kai; Tietoliikenne- ja tietoverkkotekniikan laitos; Department of Communications and Networking; Sähkötekniikan korkeakoulu; School of Electrical Engineering; Manner, Jukka, Prof., Aalto University, Department of Communications and Networking , Finland
    Transformations of military enterprises seek to use technology to gain better performance, provide more effective outcomes, and excel in the space and time of confrontation. Enterprise Architecture should provide methods and competencies to gain more understanding of transformations and improve the success of these journeys. However, military transformations have a record of a variety of challenges and often fail to deliver intended outcomes. Possibly, the enterprise architecture practitioners are trying to engage a moving target. The failures do not notably follow any exact pattern or line of correlation. Still, they seem to be distributed through the layers of the military structure. Despite the evident problem and risk to national security, there is a surprising lack of research in this field. The dissertation approaches the challenges in military transformations from an enterprise architecture view in a quest to find models that would better explain the interrelationships between the military environment, affairs, knowledge, information, and technology over time—in other words, trying to engage an evolutionary enterprise and see where it may be going. The dissertation approaches the problem from a pragmatic view using a design science approach to create a better tool in modelling the dynamics and evolution of the military enterprise. Since the components and layers of an enterprise follow a different logic, the design needs to apply transdisciplinary research methods appropriate to each layer of the enterprise system. The proposed EA tool improves the quality of an enterprise architect's analysis of military transformations in recognising the current situation, seeing the paths of evolution leading to the current position, and foreseeing both the challenges and opportunities in journeys towards the strategic end state. Furthermore, the EA tool reveals some of the hidden forces driving or hindering the change of an enterprise, and therefore improving the success of digital transformation in the military context. The military decision making may benefit from the improved architectural insight and foresight when defining national-level strategies, implementing changes, maintaining operational capabilities, and, lately, obtaining the most out of their digital transformations.
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    A hybrid approach to quality measurements in mobile networks
    (Aalto University, 2020) Boz, Eren; Manner, Jukka, Prof., Aalto University, Department of Communications and Networking , Finland; Tietoliikenne- ja tietoverkkotekniikan laitos; Department of Communications and Networking; Sähkötekniikan korkeakoulu; School of Electrical Engineering; Manner, Jukka, Prof., Aalto University, Department of Communications and Networking , Finland
    The mobile-first era is here. Due to constantly increasing demand for mobile data, cellular network infrastructures running on limited radio spectrum are struggling to keep up. Constant monitoring and measurements are necessary to ensure service availability and quality as saturated networks are not able to deliver consistent experience. Such measurements are especially crucial for mission-critical use cases such as public safety as they increasingly rely on commercial networks. However, measuring mobile networks at scale bears some fundamental problems. Although there are significant improvements in capabilities of mobile networks (e.g. bit rate, latency), measuring them is still rather complicated task compared to fixed networks given that in mobile networks, performance is a result of complex interaction between momentary cell load, adjacent cell interference, shadowing, fading, mobility and user device capabilities. The adoption of commercial 5G networks is expected to increase the variability even more as it depends on smaller cells. Active measurements that inject large amounts of traffic into the network for the sole purpose of measuring are costly in terms of both bandwidth and energy. Passive mechanisms are lightweight but miss the information of why a certain bit rate is received or sent by the end device. They can not tell whether the performance bottleneck is in the network or in the service itself. On the other hand, modern mobile platforms provide a great diversity of networked applications that have varying network resource demands. It is often hard to estimate which aspect of mobile network performance is relevant to the quality that users experience. For example, just providing an excess of downlink bandwidth at the expense of packet loss or latency might not cut it for highly interactive real-time applications.By combining active and passive measurements in a novel way, this work focuses on a hybrid measurement approach to quality measurements in mobile networks. First, an efficient and scalable hybrid methodology is proposed and evaluated for mobile network Quality-of-Service measurements. Then building on top of it, mobile Quality-of-Experience and its predictability in the field via smartphones is empirically investigated by carrying out extensive field studies. The thesis concludes by evaluating the findings to establish future work necessary to achieve pervasive mobile measurements that are capable of both reflecting user-perceived quality and predicting mobile performance as an enabler of network adaptive applications.
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    Mobile network delay characteristics and interactions with the transport layer
    (Aalto University, 2017) Schulte, Lennart; Manner, Jukka, Prof., Aalto University, Department of Communications and Networking , Finland; Tietoliikenne- ja tietoverkkotekniikan laitos; Department of Communications and Networking; Sähkötekniikan korkeakoulu; School of Electrical Engineering; Manner, Jukka, Prof., Aalto University, Department of Communications and Networking, Finland
    Mobile networks have become an integral part of every day life, and many users rely on its presence and performance. In the past years user num bers and traffic volume has skyrocketed, as adoption of the technology continues to increase. The popularity of internet based services in mobile networks and the increase in user numbers makes the available resources precious and ever more important to use them: a user's satisfaction is inversely proportional to the time it takes for the requested content to load. While the mobile network sets an upper bound on the transmission rate, it is up to the delivering end point to make use of these resources, which for many applications is in the hands of the Transmission Control Protocol (TCP). As TCP has to make the best use of the resources in every situation, it is vital to understand the interactions between the protocol and the mobile network in order to achieve best performance. This work is a measurement based study on the performance of TCP in Finnish 3rd generation (3G) and 4th generation (4G) mobile networks. First, it is investigated how the round-trip time (RTT) behaves throughout end-to-end connections traversing mobile networks, on long term as well as on short term in the form of delay spikes. Second, the proper way for TCP to deal with these delay spikes is examined. Lastly, the interactions of TCP with the mobile network is investigated in real-life situations and causes for sub-optimal performance is extracted. The thesis concludes with a discussion on what is necessary to improve TCP performance in mobile networks, and the changes coming with future networks and algorithms.
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    Resource Assignments in Network Data Transport
    (Aalto University, 2020) Moktan, Gautam Raj; Manner, Jukka, Prof., Aalto University, Department of Communications and Networking , Finland; Tietoliikenne- ja tietoverkkotekniikan laitos; Department of Communications and Networking; Sähkötekniikan korkeakoulu; School of Electrical Engineering; Manner, Jukka, Prof., Aalto University, Department of Communications and Networking , Finland
    Communication networks have come a long way since their invention and adoption in the modern society. They have fundamentally changed how society functions and the speed at which activities are conducted. Colossal amount of data is transported through today's networks to convey information between various end points. The Internet is the largest information and communication network shared by billions of end points as a common medium of data transfer today. The amount of data that can be transported through these networks within a given time period, also known as bandwidth, is the principal resource shared between the different end points. And, as is the case with many other finite resources available to modern society, scarcity of resources has led to the development of various schemes of resource distribution. The Transmission Control Protocol (TCP) is the dominant mechanism for transporting data between end points in the Internet. It provides various functionalities such as ensuring that the data is transported reliably between the end points and preventing the receiver and the network from being overwhelmed by too much data sent. TCP implements congestion control mechanisms so that multiple flows can share the network capacity. This thesis analyses the sharing of network resources in communication networks, using a customized TCP variant. Traditionally, TCP treats all flows as equal regardless of their end utility and attempts to provide equal share of the network bandwidth to each flow. This research analyses a scenario without that assumption. Specifically, short and long data transfers are considered unequal. As a manifestation of such concept, the research work developed a TCP congestion control variant which was able to provide different share of network capacity to different flow types. The performance of the protocol was then tested under multiple settings to investigate the notion further and evaluate the implications for deployment at large. Solutions to the resource assignment problem merit not just technical but also socio-economic analysis. The research explores the development of different resource assignment schemes in society at large and finds analogous schemes in communication networks. By comprehending the various notions of fairness prevalent in the society, several concerns to be addressed while developing resource assignment schemes are identified.