60,288 research outputs found

    Millimeter Wave Cellular Networks: A MAC Layer Perspective

    Full text link
    The millimeter wave (mmWave) frequency band is seen as a key enabler of multi-gigabit wireless access in future cellular networks. In order to overcome the propagation challenges, mmWave systems use a large number of antenna elements both at the base station and at the user equipment, which lead to high directivity gains, fully-directional communications, and possible noise-limited operations. The fundamental differences between mmWave networks and traditional ones challenge the classical design constraints, objectives, and available degrees of freedom. This paper addresses the implications that highly directional communication has on the design of an efficient medium access control (MAC) layer. The paper discusses key MAC layer issues, such as synchronization, random access, handover, channelization, interference management, scheduling, and association. The paper provides an integrated view on MAC layer issues for cellular networks, identifies new challenges and tradeoffs, and provides novel insights and solution approaches.Comment: 21 pages, 9 figures, 2 tables, to appear in IEEE Transactions on Communication

    Comprehensibility and the basic structures of dialogue

    Get PDF
    The study of what makes utterances difficult or easy to understand is one of the central topics of research in comprehension. It is both theoretically attractive and useful in practice. The more we know about difficulties in understanding the more we know about understanding. And the better we grasp typical problems of understanding in certain types of discourse and for certain recipients the better we can overcome these problems and the better we can advise people whose job it is to overcome such problems. It is therefore not surprising that comprehensibility has been the object of much reflection as far back as the days of classical rhetoric and that it is a center of lively interest in several present-day scientific disciplines, ranging from artificial intelligence and educational psychology to linguistics

    Signalling Storms in 3G Mobile Networks

    Full text link
    We review the characteristics of signalling storms that have been caused by certain common apps and recently observed in cellular networks, leading to system outages. We then develop a mathematical model of a mobile user's signalling behaviour which focuses on the potential of causing such storms, and represent it by a large Markov chain. The analysis of this model allows us to determine the key parameters of mobile user device behaviour that can lead to signalling storms. We then identify the parameter values that will lead to worst case load for the network itself in the presence of such storms. This leads to explicit results regarding the manner in which individual mobile behaviour can cause overload conditions on the network and its signalling servers, and provides insight into how this may be avoided.Comment: IEEE ICC 2014 - Communications and Information Systems Security Symposiu

    Text categorization and similarity analysis: similarity measure, literature review

    Get PDF
    Document classification and provenance has become an important area of computer science as the amount of digital information is growing significantly. Organisations are storing documents on computers rather than in paper form. Software is now required that will show the similarities between documents (i.e. document classification) and to point out duplicates and possibly the history of each document (i.e. provenance). Poor organisation is common and leads to situations like above. There exists a number of software solutions in this area designed to make document organisation as simple as possible. I'm doing my project with Pingar who are a company based in Auckland who aim to help organise the growing amount of unstructured digital data. This reports analyses the existing literature in this area with the aim to determine what already exists and how my project will be different from existing solutions

    Developing Understandings of Collaborative Partnerships Between University and Community

    Get PDF
    University faculty define collaborative partnerships with the community and examine how collaborative partnerships engender community-based research and the learning process of students in the College of Public Service. Considerations include how students are acculturated, specific benefits to learning, unanticipated benefits, and the unexpected challenges of collaborative partnerships between a university and a community

    Managing Knowledge in a Distributed Decision Making Context

    Get PDF
    This paper considers the role of electronic communication in the creation and distribution of knowledge, and in particular, the creation and sharing of personalised knowledge. Personalised knowledge or "intellectual capital" is perhaps a least understood but most important asset of modern organisations. This paper reveals the creation and sharing of personalised knowledge in a network organisation. The network organisation investigated in this paper relies on electronic communication in a distributed decision making context to leverage the skills and intellect of its key professionals. This paper investigates electronic group meetings that take place on this electronic social space to analyse key processes of knowledge creation. Implications for managing distributed personalised knowledge are discussed and conclusions drawn with respect to the key decision support systems functionalities required for managing knowledge in situations where decision making is distributed and takes place on an electronic social space.Personalised Knowledge;c entrality;communication infrastructure;distributed decision support;electronic social space;prestige

    Design enquiry: tacit knowledge and invention in science

    Get PDF
    For some years there has been discussion and speculation on the subject of "design enquiry" and a number of people, for example Richard Buchanan and Clive Dilnot , have looked for forms of enquiry appropriate to, or fruitful for, design as an academic and professional discipline. From a different perspective, Ranulph Glanville has suggested that the relationship between design and science might be redefined to acknowledge similarities of method that are disguised by forms of narrative employed by scientists. However most contributions in these debates deal with generalisations so I would like to propose some specific ways in which designers can explore and develop the concepts and practices of design enquiry. In particular I would like to discuss a kind of enquiry where designers can play a role in forming and pursuing questions which arise in the natural sciences and I will suggest that this role might be extended into some other fields. In doing so I will make reference to the subject of tacit knowledge, a concept which was formalised by Michael Polanyi in his consideration of the philosophy of science 50 years ago and which has attracted continuing interest (his 1958 book, Personal Knowledge, was reprinted most recently in 1998 and 2002), but also some shallow interpretation since then. I believe that Polanyi has a great deal to offer the design community, perhaps more in some respects than the widely cited work of Donald Schon who dealt with general questions of practice relevant to many disciplines while Polanyi addressed the relationship between enquiry and creativity in a very direct way. </p
    • 

    corecore