11,634 research outputs found
Mobility Management in beyond 3G-Environments
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
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Health and mobility: Current status and future paradigms
The movement of telemedicine to the wireless and mobile Internetable applications is imminent in the next few years. This migration from the desktop platforms to the wireless and mobile configurations will have significant impact on the future health care delivery system and their globalisation. The recent telecommunications and biomedical computing advances will significantly enhance the current methodologies of telemedicine and telecare systems. This editorial will present some of the evolutionary issues and important aspects that have to be considered in the developing technologies for the next generation of Internet and Third Generation of Mobile Systems (3G), geared for future telemedical applications. These will provide new dimensions to existing medical services and areas of outreach, that are not possible in the current generation and will have tremendous impact on how the health care delivery will be shaped for the 21 Century
TechNews digests: Autumn 2004
TechNews is a technology, news and analysis service aimed at anyone in the education sector keen to stay informed about technology developments, trends and issues. TechNews focuses on emerging technologies and other technology news. TechNews service : digests september 2004 till May 2010 Analysis pieces and News combined publish every 2 to 3 month
EVEREST IST - 2002 - 00185 : D23 : final report
Deliverable pĂșblic del projecte europeu EVERESTThis deliverable constitutes the final report of the project IST-2002-001858 EVEREST. After its successful completion, the project presents this document that firstly summarizes the context, goal and the approach objective of the project. Then it presents a concise summary of the major goals and results, as well as highlights the most valuable lessons derived form the project work. A list of deliverables and publications is included in the annex.Postprint (published version
QoS Based Capacity Enhancement for WCDMA Network with Coding Scheme
The wide-band code division multiple access (WCDMA) based 3G and beyond
cellular mobile wireless networks are expected to provide a diverse range of
multimedia services to mobile users with guaranteed quality of service (QoS).
To serve diverse quality of service requirements of these networks it
necessitates new radio resource management strategies for effective utilization
of network resources with coding schemes. Call admission control (CAC) is a
significant component in wireless networks to guarantee quality of service
requirements and also to enhance the network resilience. In this paper capacity
enhancement for WCDMA network with convolutional coding scheme is discussed and
compared with block code and without coding scheme to achieve a better balance
between resource utilization and quality of service provisioning. The model of
this network is valid for the real-time (RT) and non-real-time (NRT) services
having different data rate. Simulation results demonstrate the effectiveness of
the network using convolutional code in terms of capacity enhancement and QoS
of the voice and video services.Comment: 10 Pages, VLSICS Journa
Mobility: a double-edged sword for HSPA networks
This paper presents an empirical study on the performance of mobile High Speed Packet Access (HSPA, a 3.5G cellular standard) networks in Hong Kong via extensive field tests. Our study, from the viewpoint of end users, covers virtually all possible mobile scenarios in urban areas, including subways, trains, off-shore ferries and city buses. We have confirmed that mobility has largely negative impacts on the performance of HSPA networks, as fast-changing wireless environment causes serious service deterioration or even interruption. Meanwhile our field experiment results have shown unexpected new findings and thereby exposed new features of the mobile HSPA networks, which contradict commonly held views. We surprisingly find out that mobility can improve fairness of bandwidth sharing among users and traffic flows. Also the triggering and final results of handoffs in mobile HSPA networks are unpredictable and often inappropriate, thus calling for fast reacting fallover mechanisms. We have conducted in-depth research to furnish detailed analysis and explanations to what we have observed. We conclude that mobility is a double-edged sword for HSPA networks. To the best of our knowledge, this is the first public report on a large scale empirical study on the performance of commercial mobile HSPA networks
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