Client-based SBM layer for predictive management of traffic flows in heterogeneous networks

In a heterogeneous networking environment, the knowledge of the time before a vertical handover (TBVH) for any network is vital in correctly assigning connections to available channels. In this paper, we introduce a predictive mathematical model for calculating the estimated TBVH component from available network parameters and discuss the different scenarios that arise based on a mobile host’s trajectory. We then introduce the concept of an intelligent Stream Bundle Management Layer (SBM) which consists of a set of policies for scheduling and mapping prioritised traffic streams on to available channels based on their priority, device mobility pattern and prevailing channel conditions. The layer is also responsible for the maintenance of connections during vertical handovers to avoid their forced termination

Fall Prediction and Prevention Systems: Recent Trends, Challenges, and Future Research Directions.

Fall prediction is a multifaceted problem that involves complex interactions between physiological, behavioral, and environmental factors. Existing fall detection and prediction systems mainly focus on physiological factors such as gait, vision, and cognition, and do not address the multifactorial nature of falls. In addition, these systems lack efficient user interfaces and feedback for preventing future falls. Recent advances in internet of things (IoT) and mobile technologies offer ample opportunities for integrating contextual information about patient behavior and environment along with physiological health data for predicting falls. This article reviews the state-of-the-art in fall detection and prediction systems. It also describes the challenges, limitations, and future directions in the design and implementation of effective fall prediction and prevention systems

Modelling Participation in Virtual Environments

Submitted to the University of London for the Degree of Doctor of Philosophy in Computer Science

When traditional advocacy goes high-tech

This thesis defines the essentials of activism and gives examples of online technology that can assist grassroots organizations in promoting positive change within their communities. I discuss existing online technologies that make it possible for grassroots organizations to enhance the traditional (non-Internet-based) approaches to activism. Online activism is a growing trend among non-profit organizations. Several online awards are given to organizations that have noticeably pursued online pursuit of electronic advocacy. From making telephone calls to organizing demonstrations, grassroots groups can begin saving money, time, and human resources. The Internet frees people from physical barriers and borders. I have investigated current online technologies that can be used to supplement traditional activism services. I give one example per approach that can be used online. The examples include self-education, promoting your organization\u27s message, successful online actions, information distribution, corporate utilization, and the future of online activism. Examples of activism in this report focus on non-violent advocacy or civil disobedience. I have researched online activism through the use of periodicals, books, World Wide Web Internet searches, and interviews with advocacy specialists. This report offers evidence that the Internet has changed, and will continue to change, the paradigm of political and social activism. By providing increased access using new, fast, and efficient technology, more people are able to have a greater say in shaping their worlds

Framework to facilitate smooth handovers between mobile IPv6 networks

Fourth generation (4G) mobile communication networks are characterised by heterogeneous access networks and IP based transport technologies. Different access technologies give users choices to select services such as levels of Quality of Service (QoS) support, business models and service providers. Flexibility of heterogeneous access is compounded by the overhead of scanning to discover accessible services, which added to the handoff latency. This thesis has developed mechanisms for service discovery and service selection, along with a novel proposal for mobility management architectures that reduced handoff latency. The service discovery framework included a service advertisement data repository and a single frequency band access mechanism, which enabled users to explore services offered by various operators with a reduced scanning overhead. The novel hierarchical layout of the repository enabled it to categorise information into various layers and facilitate location based information retrieval. The information made available by the repository included cost, bandwidth, Packet Loss (PL), latency, jitter, Bit Error Rate (BER), location and service connectivity information. The single frequency band access mechanism further enabled users to explore service advertisements in the absence of their main service providers. The single frequency access mechanism broadcasted service advertisements information piggybacked onto a router advertisement packet on a reserved frequency band for advertisements. Results indicated that scanning 13 channels on 802.11 b interface takes 189ms whereas executing a query with maximum permissible search parameters on the service advertisement data repository takes 67ms. A service selection algorithm was developed to make handoff decisions utilising the service advertisements acquired from the service discovery framework; based on a user's preference. The selection algorithm reduced the calculation overhead by eliminating unsuitable networks; based on interface compatibility, service provider location, unacceptable QoS (Quality of service) and unacceptable cost; from the selection process. The selection algorithm utilised cost, bandwidth, PL, latency, jitter, BER and terminal power for computing the most suitable network. Results indicated that the elimination based approach has improved the performance of the algorithm by 35% over non- elimination oriented selection procedures, even after utilising more selection parameters. The service discovery framework and the service selection algorithm are flexible enough to be employed in most mobility management architectures. The thesis recommends Seamless Mobile Internet Protocol (SMIP) as a mobility management scheme based on the simulation results. The SMIP protocol, a combination of Hierarchical Mobile Internet Protocol (HMIP) and Fast Mobile Internet Protocol (FMIP), suffered hand off latency increases when undergoing a global handoff due to HMIP. The proposed modification to the HMIP included the introduction of a coverage area overlap, to reduce the global handoff latency. The introduction of a Home Address (HA) in Wireless Local Area Networks (WLAN) binding table enabled seamless handoffs from WLANs by having a redirection mechanism for the user's packets after handoff. The thesis delivered a new mobility management architecture with mechanisms for service discovery and service selection. The proposed framework enabled user oriented, application centric and terminal based approach for selecting IPv6 networks

Application Platforms, Routing Algorithms and Mobility Behavior in Mobile Disruption-Tolerant Networks

Mobile disruption-tolerant networks (DTNs), experience frequent and long duration partitions due to the low density of mobile nodes. In these networks, traditional networking models relying on end-to-end communication cease to work. The topological characteristics of mobile DTNs impose unique challenges for the design and validation of routing protocols and applications. We investigate challenges of mobile DTNs from three different viewpoints: the application layer, a routing perspective, and by studying mobility patterns. In the application layer, we have built 7DS (7th Degree of Separation) as a modular platform to develop mobile disruption-tolerant applications. 7DS offers a class of disruption-tolerant applications to exchange data with other mobile users in the mobile DTN or with the global Internet. In the routing layer, we have designed and implemented PEEP as an interest-aware and energy efficient routing protocol which automatically extracts individual interests of mobile users and estimates the global popularity of data items throughout the network. PEEP considers mobile users' interests and global popularity of data items in its routing decisions to route data toward the community of mobile users who are interested in that data content. Mobility of mobile users impacts the conditions in which routing protocols for mobile DTNs must operate and types of applications that could be provided for mobile networks in general. The current synthetic mobility models do not reflect real-world mobile users' behavior. Trace-based mobility models, also, are based on traces that either represent a specific population of mobile users or do not have enough granularities in representing mobility of mobile users for example cell tower traces. We use Sense Networks' GPS traces that are being collected by monitoring a broad spectrum of mobile users. Using these traces, we employ a Markovian approach to extract inherent patterns in human mobility. We design and implement a new routing algorithm for mobile DTNs based on our Markovian analysis of the human mobility. We explore how the knowledge of the mobility improves the performance of our Markov based routing algorithm. We show that that our Markov based routing algorithm increases the rate of data delivery to popular destinations with consuming less energy than legacy algorithms

Keeping up with the information glut by visualizing patterns of posting by friends on Facebook

Users of social networks, such as Facebook, are becoming increasingly overwhelmed by the growing number of "friends" that they are connected to and the "tsunami" of updates generated by them. It is very easy to miss potentially interesting updates, if one does not frequently check her news feed. Also it is hard to get a sense of which friends are active and especially, which are passive or completely gone. Awareness of friends and friends' activities is one of the utmost importance for a user to build trusted social networks. However, current online social networks provide only very limited clues to support these two kinds of awareness. Therefore, I propose a method to visualize the activity level of friends. It creates a time- and an activity-pattern awareness for the user, as well as an awareness of the lurkers. It also offers options to filter activity streams regarding particular time periods/friends

Studies and a model of appropriation of information and communication technologies in university students’ everyday life

This thesis investigated the appropriation of information and communication technologies in everyday life among university students and mature people. To that end, pertinent literature was reviewed resulting in the identification of three issues in need of a more careful appraisal by the HCI field. These issues were used as the research questions propelling this work; they include the identification of elements favouring the process of appropriation; the effect of a changing context on this process; and the co-existence of seemingly overlapping ICTs in people’s lives. A qualitative methodology was utilised in the studies reported in this thesis. Ethnographic work was conducted over a period of three months with fifteen masters students at the University of Glasgow in the UK. Further ethnographic work over a shorter time frame was conducted abroad among university students at Hokkaido University in Japan, Ajou University in South Korea and Nankai University in China. Additional ethnographic work was conducted among mature people in a religious community in Mexico. Qualitative data gathered was analysed using Grounded Theory and Structuration Theory. Two are the main contributions of this work. First, a number of insights providing some answers to the research questions posited in this thesis. These answers were advanced as a complement and expansion to issues previously identified in the literature as relevant in the process of appropriation. Because of the ecological perspective underlying this thesis, these answers were presented as technology-neutral and yet useful to understand how the appropriation of technology is induced and sustained, what the impact of a changing environment in the process of appropriation is, and how similar technologies with overlapping features can thrive in the same environment. The second contribution of this work was a three-layered model of appropriation of ICTs built from the identification of common patterns across the studies conducted. This model sought to detail the role of several intersecting large-scale social processes or structures (i.e., governments, various-sized private and state-owned organisations, the media, families and peers, as well as marketing practices, technical infrastructures and architectural spaces) that provide the resources and restrictions upon which the process of appropiation of digital technology rests. This framework was advanced as a simple tool to aid HCI researchers in the collection, analysis and reporting of qualitative data around the process of appropriation as shaped by the pervasive social structures of contemporary society. The limitations of the ethnographic work here reported, as well as those of the ensuing conclusions, are identified and used to suggest some avenues of future exploration around the appropriation of ICTs in daily life