Supporting the Mobile Querying of Existing Online Semantic Web Data for Context-Aware Applications

[EN] Mobile devices are increasingly multifunctional and personal, providing mobile applications with the necessary user information to achieve personalization. At the same time, detection technologies let such devices find nearby physical entities and thus map the user's environment. By exploiting existing online Semantic Web sources about these detected entities, mobile applications can further improve personalization. SCOUT is a mobile application framework that supports linking physical entities to online semantic data sources. It provides applications with an integrated, query-able view on these sources and the user's environment. The authors developed a tailored data management approach to efficiently access these distributed online semantic sources.Sven Casteleyn is supported by EC Marie Curie grant FP7- PEOPLE-2009-IEF, number 254383.Van Woensel, W.; Casteleyn, S.; Paret, E.; De Troyer, O. (2011). Supporting the Mobile Querying of Existing Online Semantic Web Data for Context-Aware Applications. IEEE Internet Computing. 15(6):32-39. https://doi.org/10.1109/MIC.2011.108323915

Capturing and Sharing Human Digital Memories with the Aid of Ubiquitous Peer– to–Peer Mobile Services

The explosion of mobile computing and the sharing of content ubiquitously has enabled users to create and share memories instantly. Access to different data sources, such as location, movement, and physiology, has helped to create a data rich society where new and enhanced memories will form part of everyday life. Peer–to–Peer (P2P) systems have also increased in popularity over the years, due to their ad hoc and decentralized nature. Mobile devices are “smarter” and are increasingly becoming part of P2P systems; opening up a whole new dimension for capturing, sharing and interacting with enhanced human digital memories. This will require original and novel platforms that automatically compose data sources from ubiquitous ad-hoc services that are prevalent within the environments we occupy. This is important for a number of reasons. Firstly, it will allow digital memories to be created that include richer information, such as how you felt when the memory was created and how you made others feel. Secondly, it provides a set of core services that can more easily manage and incorporate new sources as and when you are available. In this way memories created in the same location, and time are not necessarily similar – it depends on the data sources that are accessible. This paper presents DigMem, the initial prototype that is being developed to utilize distributed mobile services. DigMem captures and shares human digital memories, in a ubiquitous P2P environment. We present a case study to validate the implementation and evaluate the applicability of the approach

The design and optimization of cooperative mobile edge

As the world is charging towards the Internet of Things (IoT) era, an enormous amount of sensors will be rapidly empowered with internet connectivity. Besides the fact that the end devices are getting more diverse, some of them are also becoming more powerful, such that they can function as standalone mobile computing units with multiple wireless network interfaces. At the network end, various facilities are also pushed to the mobile edge to foster internet connections. Distributed small scale cloud resources and green energy harvesters can be directly attached to the deployed heterogeneous base stations. Different from the traditional wireless access networks, where the only dynamics come from the user mobility, the evolving mobile edge will be operated in the constantly changing and volatile environment. The harvested green energy will be highly dependent on the available energy sources, and the dense deployment of a variety of wireless access networks will result in intense radio resource contention. Consequently, the wireless networks are facing great challenges in terms of capacity, latency, energy/spectrum efficiency, and security. Equivalently, balancing the dynamic network resource demand and supply is essential to the smooth network operation. Leveraging the broadcasting nature of wireless data transmission, network nodes can cooperate with each other by either allowing users to connect with multiple base stations simultaneously or offloading user workloads to neighboring base stations. Moreover, grid facilitated and radio frequency signal enabled renewable energy sharing among network nodes are introduced in this dissertation. In particular, the smart grid can transfer the green energy harvested by each individual network node from one place to another. The network node can also transmit energy from one to another using radio frequency energy transfer. This dissertation addresses the cooperative network resource management to improve the energy efficiency of the mobile edge. First, the energy efficient cooperative data transmission scheme is designed to cooperatively allocate the radio resources of the wireless networks, including spectrum and power, to the mobile users. Then, the cooperative data transmission and wireless energy sharing scheme is designed to optimize both the energy and data transmission in the network. Finally, the cooperative data transmission and wired energy sharing scheme is designed to optimize the energy flow within the smart grid and the data transmission in the network. As future work, how to motivate multiple parties to cooperate and how to guarantee the security of the cooperative mobile edge is discussed. On one hand, the incentive scheme for each individual network node with distributed storage and computing resources is designed to improve network performance in terms of latency. On the other hand, how to leverage network cooperation to balance the tradeoff between efficiency (energy efficiency and latency) and security (confidentiality and privacy) is expounded

QoE-Assured 4K HTTP live streaming via transient segment holding at mobile edge

HTTP-based live streaming has become increasingly popular in recent years, and more users have started generating 4K live streams from their devices (e.g., mobile phones) through social-media service providers like Facebook or YouTube. If the audience is located far from a live stream source across the global Internet, TCP throughput becomes substantially suboptimal due to slow-start and congestion control mechanisms. This is especially the case when the end-to-end content delivery path involves radio access network (RAN) at the last mile. As a result, the data rate perceived by a mobile receiver may not meet the high requirement of 4K video streams, which causes deteriorated Quality-of-Experience (QoE). In this paper, we propose a scheme named Edge-based Transient Holding of Live sEgment (ETHLE), which addresses the issue above by performing context-aware transient holding of video segments at the mobile edge with virtualized content caching capability. Through holding the minimum number of live video segments at the mobile edge cache in a context-aware manner, the ETHLE scheme is able to achieve seamless 4K live streaming experiences across the global Internet by eliminating buffering and substantially reducing initial startup delay and live stream latency. It has been deployed as a virtual network function at an LTE-A network, and its performance has been evaluated using real live stream sources that are distributed around the world. The significance of this paper is that by leveraging on virtualized caching resources at the mobile edge, we have addressed the conventional transport-layer bottleneck and enabled QoE-assured Internet-wide live streaming to support the emerging live streaming services with high data rate requirements

Online and digital media usage on cell phones among low-income urban youth in Cape Town

Includes bibliographical references (leaves 69-76).Cell phones introduce a range of new possibilities for the use and production of media, for social networking and communication, political activism, and social development. For this study, 441 grade 11 students at nine schools in low-income areas in Cape Town, South Africa were surveyed about their use of cell phones. These young South Africans have adopted a number of ways to use the Web and mobile Instant Messaging. They also commonly access, produce, and share digital media via their phones and the Internet. Internet access has, until recently, only been accessible to the wealthiest fraction of South African society (about 10% of the population) and so this is a highly significant development. Until now, little quantitative data has been available to describe exactly to what extent and how this cohort is beginning to access and use the Internet and digital media on cell phones. The students reported intensive use of cell phones to access mobile Internet applications, at a far greater level than they report using desktop computers to access the Web. Mobile Internet is considerably more accessible to these students than computer-based Internet access and they are choosing to use the Internet primarily for mobile instant messaging and other characteristic forms of mobile media use. This suggests that these students encounter a distinct, mobile version of the Internet. Their experience of Internet access and digital media may consequently be quite different to that of their computer-using peers. An exploratory media and technology usage approach was chosen to determine first, the availability of cell phones and specific features to the students, and, second, the extent to which online and digital media are being accessed, produced, or shared. A detailed questionnaire was distributed to all students from thirteen grade 11 classes at nine schools (n=441). The schools were chosen as random cluster samples from all public secondary schools located in the city's 50% most deprived areas in order to provide a detailed assessment of cell phone usage in an environment similar to that which prevails in many urban South African schools. Activity-based questions indicate that a majority of respondents (68%) have used a cell phone on the previous day to access the Internet, while half of all respondents (49%) used the mobile Internet to access the Web on the previous day. Interpersonal communication was still the most common use of phones, with 87% of respondents making calls or sending SMS messages on a typical day. A significant minority (23%) of students did not own their own personal handset, despite the near universal use of cell phones among all respondents (96% use one on a typical day). While phone ownership correlated strongly with a sense of economic deprivation as well as lower academic performance, there was no significant difference between both groups in terms of their mobile Internet usage. Thus the fact that some students do not own a phone does not seem to create a 'mobile divide' or automatically lead to exclusion from the possibilities of mobile Internet access. Online media were found to be less frequently used than broadcast and print sources. Nonetheless, the fact that 28% of low-income urban youth access online news about once every day, or more often, may have significant implications for South Africa's news media, particularly in the future. Despite the geographical limitations of this study, the results provide an illuminating snapshot of mobile media use by low-income school-going youth in urban Cape Town

Towards a Framework for Developing Mobile Agents for Managing Distributed Information Resources

Distributed information management tools allow users to author, disseminate, discover and manage information within large-scale networked environments, such as the Internet. Agent technology provides the flexibility and scalability necessary to develop such distributed information management applications. We present a layered organisation that is shared by the specific applications that we build. Within this organisation we describe an architecture where mobile agents can move across distributed environments, integrate with local resources and other mobile agents, and communicate their results back to the user

Context for Ubiquitous Data Management

In response to the advance of ubiquitous computing technologies, we believe that for computer systems to be ubiquitous, they must be context-aware. In this paper, we address the impact of context-awareness on ubiquitous data management. To do this, we overview different characteristics of context in order to develop a clear understanding of context, as well as its implications and requirements for context-aware data management. References to recent research activities and applicable techniques are also provided