50,008 research outputs found

    Mobility Management in beyond 3G-Environments

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    Beyond 3G-environments are typically defined as environments that integrate different wireless and fixed access network technologies. In this paper, we address IP based Mobility Management (MM) in beyond 3G-environments with a focus on wireless access networks, motivated by the current trend of WiFi, GPRS, and UMTS networks. The GPRS and UMTS networks provide countrywide network access, while the WiFi networks provide network access in local areas such as city centres and airports. As a result, mobile end-users can be always on-line and connected to their preferred network(s), these network preferences are typically stored in a user profile. For example, an end-user who wishes to be connected with highest bandwidth could be connected to a WiFi network when available and fall back to GPRS when moving outside the hotspot area.\ud In this paper, we consider a combination of MM for legacy services (like web browsing, telnet, etc.) using Mobile IP and multimedia services using SIP. We assume that the end-user makes use of multi-interface terminals with the capability of selecting one or more types of access networks\ud based on preferences. For multimedia sessions, like VoIP or streaming video, we distinguish between changes in network access when the end-user is in a session or not in a session. If the end-user is not in a session, he or she needs to be able to start new sessions and receive invitations for new sessions. If the end-user is in a session, the session needs to be handed over to the new access network as seamless as possible from the perspective of the end-user. We propose an integrated but flexible solution to these problems that facilitates MM with a customizable transparency to applications and end-users

    Privileged Mexican migrants in Europe: Distinctions and cosmopolitanism on social networking sites

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    This article examines the ways in which classed distinctions are related to the construction of increasingly cosmopolitan identities on Social Networking Sites (SNSs) amongst Mexican migrants from relatively privileged backgrounds living in Europe. It centres on how user demographics shape many of the concerns and outcomes pertaining to the use of SNSs. It considers the implications of the fact that SNSs are predominantly used by a demographic considered as non-marginalized, mobile and as possessing relatively privileged economic, cultural and social backgrounds. It analyses the ways in which online identities are constructed on SNS profiles using multimedia content to represent specific lifestyles and cultural practices that are used to make distinctions amongst participants, and are related to social, cultural and economic capital. A critical analysis is presented as to how users represent cosmopolitan identities online through the display of tastes and lifestyles in SNS content and into how these representations relate to users’ privileged positions in Mexican society. Bourdieu’s concept of distinction is used to emphasize the utility of considering different forms of capital in analysing the use of SNSs and profile content generated by a specific demographic. This article demonstrates how the analysis of SNS use may contribute towards an understanding of how classed distinctions are made based on this use and of how users negotiate the posting of profile content according to these distinctions and manage (select, edit and share) their representations

    A review of personal communications services

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    This article can be accessed from the link below - Copyright @ 2009 Nova Science Publishers, LtdPCS is an acronym for Personal Communications Service. PCS has two layers of meaning. At the low layer, from the technical perspective, PCS is a 2G mobile communication technology operating at the 1900 MHz frequency range. At the upper layer, PCS is often used as an umbrella term that includes various wireless access and personal mobility services with the ultimate goal of enabling users to freely communicate with anyone at anytime and anywhere according to their demand. Ubiquitous PCS can be implemented by integrating the wireless and wireline systems on the basis of intelligent network (IN), which provides network functions of terminal and personal mobility. In this chapter, we focus on various aspects of PCS except location management. First we describe the motivation and technological evolution for personal communications. Then we introduce three key issues related to PCS: spectrum allocation, mobility, and standardization efforts. Since PCS involves several different communication technologies, we introduce its heterogeneous and distributed system architecture. IN is also described in detail because it plays a critical role in the development of PCS. Finally, we introduce the application of PCS and its deployment status since the mid-term of 1990’s.This work was supported in part by the National Natural Science Foundation of China under Grant No. 60673159 and 70671020; the National High-Tech Research and Development Plan of China under Grant No. 2006AA01Z214, and the Engineering and Physical Sciences Research Council (EPSRC) of UK under Grant EP/E060722/1

    Context Aware Adaptable Applications - A global approach

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    Actual applications (mostly component based) requirements cannot be expressed without a ubiquitous and mobile part for end-users as well as for M2M applications (Machine to Machine). Such an evolution implies context management in order to evaluate the consequences of the mobility and corresponding mechanisms to adapt or to be adapted to the new environment. Applications are then qualified as context aware applications. This first part of this paper presents an overview of context and its management by application adaptation. This part starts by a definition and proposes a model for the context. It also presents various techniques to adapt applications to the context: from self-adaptation to supervised approached. The second part is an overview of architectures for adaptable applications. It focuses on platforms based solutions and shows information flows between application, platform and context. Finally it makes a synthesis proposition with a platform for adaptable context-aware applications called Kalimucho. Then we present implementations tools for software components and a dataflow models in order to implement the Kalimucho platform

    A software-defined architecture for next-generation cellular networks

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    In the recent years, mobile cellular networks are undergoing fundamental changes and many established concepts are being revisited. New emerging paradigms, such as Software-Defined Networking (SDN), Mobile Cloud Computing (MCC), Network Function Virtualization (NFV), Internet of Things (IoT),and Mobile Social Networking (MSN), bring challenges in the design of cellular networks architectures. Current Long-Term Evolution (LTE) networks are not able to accommodate these new trends in a scalable and efficient way. In this paper, first we discuss the limitations of the current LTE architecture. Second, driven by the new communication needs and by the advances in aforementioned areas, we propose a new architecture for next generation cellular networks. Some of its characteristics include support for distributed content routing, Heterogeneous Networks(HetNets) and multiple Radio Access Technologies (RATs). Finally, we present simulation results which show that significant backhaul traffic savings can be achieved by implementing caching and routing functions at the network edge

    A comparative study of mobile technology adoption in remote Australia

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    The paper presents a comparative study of mobile technology adoption\ud and use by two communities – one Aboriginal and the other non-Aboriginal –\ud both located in a remote region of Australia, the Bloomfield River Valley of Cape\ud York. Both communities have high levels of ownership of mobile phones relative\ud to, on the one hand, the low uptake of other ICT such as fixed-line phones by the\ud Aboriginal community at Wujal Wujal and, on the other hand, the poor mobile\ud coverage in the non-Aboriginal community at Bloomfield. For both groups\ud communication is of paramount importance, followed by listening to music. In\ud addition, the Aboriginal community make extensive use of other multimedia and\ud Internet features of their devices. Key factors in the motivation to acquire mobile\ud phones, in comparison to other ICT, are the superior cost management that\ud mobiles offer for Aboriginal people and the convenience of being able to\ud communicate while away from home for Bloomfield residents. The authors\ud conclude that mobile technology needs to be taken seriously, even in areas of\ud limited coverage such as the Bloomfield River Valley
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