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

Reducing handover latency in future IP-based wireless networks:Fast Proxy Mobile IPv6

Current IP-level mobility protocols have difficulties meeting the stringent handover delay requirements of future wireless networks. At the same time they do not give sufficient control to the network to control the handover process. This paper presents an extension to Proxy Mobile IP, which is the favorite IP level mobility protocol for the 3GPP System Architecture Evolution / Long Term Evolution (SAE/LTE). The extension, Fast Proxy Mobile IPv6 (FPMIPv6), aims at solving or reducing the control and handover problem. An elementary analysis shows that FPMIPv6 can significantly reduce the handover latency and the loss of packets during handover, especially if handovers can be predicted a few tens of milliseconds before they occur

Status: Submitted

for designing personalized mobile service brokerage An overview on agent platforms (with an emphasis on mobility and security aspects) and high-level architecture of some applications designed with software agent

Designing a User Interface for Improving the Usability of a Statistical Disclosure Control Tool

Data sets often contain personal data that are not needed for analysis. Statistical Disclosure Control (SDC) is a personal data minimizing technology to reduce personal data in a data set while maintaining the utility of the data set at an acceptable level. SDC tools usage lags due to the complexity encountered by users. The aim of the research in this paper is to reduce the complexity of SDC tools via improving their ease of use. For this study information system adoption literature is reviewed, some usability challenges are identified, and a User Interface (UI) prototype is developed. From the literature, some design principles are derived related to minimal memory, feature self-descriptiveness, user guidance, navigability, minimal action, and UI familiarity. Based on these principles, a prototype is developed and evaluated. The findings suggest that the designed UI overcomes the identified UI-related issues of an SDC tool called ARX but show no significance in reducing the complexity associated with the SDC-related complexity. The findings suggest that while reducing the complexity of the UI might be a good approach to address the problem of adopting SDC technology within organizations, there is a need for complementary approaches to increase the usability and adoption of an SDC tool.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Information and Communication Technolog

Power- and delay-awareness of health telemonitoring services: the MobiHealth system case study

Emerging healthcare applications rely on personal mobile devices to monitor and transmit patient vital signs to hospital-backend servers for further analysis. However, these devices have limited resources that must be used optimally in order to meet the application user requirements (e.g. safety, usability, reliability, performance). This paper reports on a case study of a Chronic Obstructive Pulmonary Disease telemonitoring application delivered by the MobiHealth system. This system relies on a commercial mobile device with multiple (wireless) Network Interfaces (NI). Our study focuses on how NI activation strategies affect the application end-to-end data delay (important in case of an emergency situation) and the energy consumption of the device (important for device sustainability while a patient is mobile). Our results show the trade-off between end-to-end delay and battery life-time achieved by various NI activation strategies, in combination with application-data flow adaptation for realtime and near real-time data transmission. For a given mobile\ud device, our study shows an increase in battery life-time of 40-90 %, traded against higher end-to-end data delay. The insights of our studies can be used for application-data flow adaptation aiming to increase battery life-time and device sustainability for mobile patients; which effectively increases the healthcare application usability

The Functional Significance of the Lymphatic System: Harvey Lecture, December 16, 1937

Handover in future wireless communication systems must be seamless. Current IP-level mobility protocols have difficulties meeting the stringent handover delay requirements. At the same time they do not give sufficient control to the network to optimize the handover process and they do not deal well with slow connection setups of some wireless technologies. In this paper we propose an enhancement of Proxy MIPv6 (PMIPv6) with Simultaneous bindings. The result, called SPMIPv6, is a proactive network-controlled handover solution that allows some handover processes to be carried proactively while the mobile node is connected to the serving network. We analyze SPMIPv6 performance and show that the handover latency can be limited to one RTT between the mobile node and the target access router, which is typically below 10ms, and that the packet loss due to handover can be decreased and eliminated by appropriately buffering packets at the target access router. Moreover, our performance evaluation based on a SPMIPv6 implementation shows no TCP and UDP performance degradation during handovers. Two important characteristics of SPMIPv6 are its robustness to incorrect handover predictions and its built-in features to accommodate large network attachment latencies

Power- and Delay-Aware Mobile Application-Data Flow Adaptation: the MobiHealth System Case Study

Emerging healthcare applications rely on personal mobile devices to monitor patient vital signs and to send it to the hospitals-backend servers for further analysis. However, these personal mobile devices have limited resources that must be used optimally in order to meet the requirements of healthcare applications end-users: healthcare professionals and their patients. This paper reports on a case study of a cardiac telemonitoring application delivered by the so-called MobiHealth system. This system relies on a commercial personal mobile device with multiple (wireless) network interfaces (NI). The study focuses on how the choice of a NI affects the end-to-end application’s data delay (extremely important in case of patient’s emergency) and the energy consumption of the device (relating to the service sustainability while a patient is mobile). Our results show the trade-off between battery savings and the delay achieved by various NI activation strategies in combination with application-data flow adaptation. For a given mobile device, our study shows a gain of 40-90% in battery savings, traded against the higher delays (therefore applicable mainly in non-emergency cases). The insights of our studies can be used for application-data flow adaptation aiming at battery saving and prolonging device’s operation while patients being mobile

Mobility and Key Management in SAE/LTE

Often in wireless communications the cryptographic algorithm is con-sidered as ‘the security solution’ but actually it is only the nucleus. The means for using the cryptographic algorithm is the ‘key’ used by the algorithm. Thus man-agement of keys and security there-of is an important issue. The security of the key management solution should not impede mobility of devices by adding undue delays. Thus, secure and fast key management during mobility is an important is-sue for the third generation partnership project (3GPP) activity on system architec-ture evolution / long-term evolution (SAE/LTE). In this paper we review mobility and security issues with the focus of key management in SAE/LTE and present possible existing solutions together with their analysis

Power- and delay-awareness of health telemonitoring services: the MobiHealth system case study

Emerging healthcare applications rely on personal mobile devices to monitor and transmit patient vital signs to hospital-backend servers for further analysis. However, these devices have limited resources that must be used optimally in order to meet the application user requirements (e.g. safety, usability, reliability, performance). This paper reports on a case study of a Chronic Obstructive Pulmonary Disease telemonitoring application delivered by the MobiHealth system. This system relies on a commercial mobile device with multiple (wireless) Network Interfaces (NI). Our study focuses on how NI activation strategies affect the application end-to-end data delay (important in case of an emergency situation) and the energy consumption of the device (important for device sustainability while a patient is mobile). Our results show the trade-off between end-to-end delay and battery life-time achieved by various NI activation strategies, in combination with application-data flow adaptation for realtime and near real-time data transmission. For a given mobile device, our study shows an increase in battery life-time of 40- 90 %, traded against higher end-to-end data delay. The insights of our studies can be used for application-data flow adaptation aiming to increase battery life-time and device sustainability for mobile patients; which effectively increases the healthcare application usability