Context-aware Features Research Articles

Loosely coupled service composition for deployment of next generation service overlay networks

In order to provide various attractive services to users, a user-centric approach such as usergenerated contents and services and a platform which can create a service easily and efficiently have been studied and designed during the past two decades. The IEEE NGSON standard has defined a functional architecture that provides advanced overlay functions for value-added services by collaboration of services with features of context awareness, dynamic adaptation and self-organizing management. Its service composition mechanism is comparable with service oriented architecture. However, due to SOA's complexity, it has not become as popular for user-generated services and contents as so-called mashup technologies, which also provide attractive and simple service creation. In this article we propose the adoption of loosely coupled service composition into the NGSON framework that can easily integrate existing communications and data services with little to no dependence on the underlying implementation and service description language details. Furthermore, the NGSON prototype supporting our proposal is presented as a proof of concept and to verify its advantages for operators, service providers, and end users.

Enhancing Existing Communication Services with Context Awareness

Context aware communication services rely on information sources and sensors, to derive users’ current situation and potential needs, and to adapt their communication services accordingly. If extensive studies have been driven on context awareness by industrials and researchers from academia, the design of such systems without modifying uses and manners of underlying communication services—while keeping them simple, intuitive, and reactive—remains a challenge. In this work, we introduce a context aware communication system that takes into account user’s preferences, workload, and situation to customize telephony services. In this implementation, we use IMS for communication management. The benefits of this implementation are the enhancement of IMS with context awareness features, and the coupling of user preferences with contextual information to provide improved service customization, without modifying the user experience.

Transparent Caching of Virtual Stubs for Improved Performance in Ubiquitous Environments

Context-awareness is an essential requirement for pervasive computing applications, which enables them to adapt and perform tasks based on context. One of the adaptive features of context-awareness is contextual reconfiguration. Contextual reconfiguration involves discovering remote service(s) based on context and binding them to the application components to realize new behaviors, which may be needed to satisfy user needs or to enrich user experience. One of the steps in the reconfiguration process involves a remote lookup to discover the service(s) based on context. This remote lookup process provides the largest contribution to reconfiguration time and this is due to fact that the remote calls are much slower than local calls. Consequently, it affects system performance. In pervasive computing applications, this may turn out to be undesirable in terms of user experience. Moreover, other distributed applications using the network may be affected as every remote method call decreases the amount of bandwidth available on the network. Various systems provide reconfiguration support and offer high-level reconfiguration directives to develop adaptive context-aware applications, but do not address this performance bottleneck. We address this issue and implement seamless caching of virtual stubs within our PCRA1 for improved performance. In this paper we present and describe our transparent caching support and also provide its performance evaluation.

Set-top box-based communication client with the automatic operation profile selection

The introduction of IP-based services to the realm of television broadcasting, television receivers and set-top boxes, opened possibilities for different, new applications for the users in front of their TV screens. IPTV, IP-based communications, social networking and web browsing are among the newest addons to the traditional digital TV concepts. This paper presents an integration concept and the implemented solution of a communication client application for a set-top box device. The communication client is provided as an add-on to the set-top box in the form of USB flash thumb drive. In addition to the voice call and messages, more advanced challenges are recognized and implemented for this application, with regard to the ubiquitous computing concept: context-aware features including an automatic profile selection based on the activities and the availability of people watching the TV, as calculated by the use of embedded sensors and proposed algorithms; the announcement of the selected profile by the use of RGB lighting effects for the RF-controlled RGB luminaires in the living room. These suggested features aim to improve the two most general usability problems of communication client applications applied to the specific set-top box solution. Firstly, interrupting the users by the notifications produced by the application can induce negative effects to user satisfaction and/or stress, if those notifications unexpectedly occur during engaging activities, such as watching the favorite TV show or talking to a friend in the room. Therefore, automatic profile selection based on detected user activities can mitigate these situations and provide the most suitable means of notifying the user for each specific situation of his/her engagement. Secondly, ignorance of the selected profile by other people interacting in person is accounted for by the announcement of the availability by using lighting stimuli.

Status and trends of mobile-health applications for iOS devices: A developer's perspective

Modern smart mobile devices offer media-rich and context-aware features that are highly useful for electronic-health (e-health) applications. It is therefore not surprising that these devices have gained acceptance as target devices for e-health applications, turning them into m-health (mobile-health) apps. In particular, many e-health application developers have chosen Apple's iOS mobile devices such as iPad, iPhone, or iPod Touch as the target device to provide more convenient and richer user experience, as evidenced by the rapidly increasing number of m-health apps in Apple's App Store. In this paper, the top two hundred of such apps from the App Store were examined from a developer's perspective to provide a focused overview of the status and trends of iOS m-health apps and an analysis of related technology, architecture, and user interface design issues. The top 200 apps were classified into different groups according to their purposes, functions, and user satisfaction. It was shown that although the biggest group of apps was medical information reference apps that were delivered from or related to medical articles, websites, or journals, mobile users disproportionally favored tracking tools. It was clear that m-health apps still had plenty of room to grow to take full advantage of unique mobile platform features and truly fulfill their potential. In particular, introduction of two- or three-dimensional visualization and context-awareness could further enhance m-health app's usability and utility. This paper aims to serve as a reference point and guide for developers and practitioners interested in using iOS as a platform for m-health applications, particular from the technical point of view.

Comparing and Choosing Appropriate Database for Storing Context in Context Aware System

Problem statement: The databases introduce the digital era the fact that requirement to maintain large and ample data. The growth of information development and improvement that pursued it transformed the databases into a global reality. This study enquired and described the vital role of storing the context data to an appropriate database in the area of context aware computing. It also addson limitations of the existing relational and object relational databases with respect to context aware computing. Approach: This article examines traditional database like relational database, object relational database and spatial database. It helps to make an optimal decision while choosing the database for context aware applications. Results: All the traditional databases are compared with context aware features like semantic support, ease of transaction of large data, query optimization, reasoning support, formality, scalability, spatial data and xml support. Conclusion: This study confirmed that using object relational database along with ontology is more apt for storing the context data for context aware computing applications.

Consumer Value of Context Aware and Location Based Mobile Services

Context aware services have the ability to utilize information about the user’s context and adapt services to a user’s current situation and needs. In this article the authors consider users’ perceptions of the added value of location awareness and presence information in mobile services. The authors use an experimental design, where stimuli comprising specific bundles of mobile services were presented to groups of respondents. The stimuli showed increasing, manipulated, levels of context-awareness, including location of the user and location and availability of buddies as distinct levels. Their results indicate that simply adding context aware features to mobile services does not necessarily provide added value to users, rather the contrary. The potential added value of insight in buddies’ location and availability is offset by people’s reluctance to share location information with others. Although the average perceived value overall is rather low there exists a substantial minority that does appreciate the added context aware features. High scores on constructs like product involvement, social influence and self-expressiveness characterize this group. The results also show that context aware service bundles with utilitarian elements have a higher perceived value than bundles with hedonic elements. On the basis of the different results some guidelines for designing context aware mobile services are formulated.

Supporting Project Management with Fine-Grained Artefact Managementin Adams

We present the project management support in ADAMS (ADvanced Artefact Management System), a web-based system that integrates project management features such as resource allocation and process control and artefact management features, such as coordination of cooperative workers and artefact versioning, as well as context-awareness and artefact traceability features. We also present an evaluation of the usefulness and adequacy of the functionalities that ADAMS provides to the project managed. This evaluation has been conducted during the last 3 years with Master students attending a course of Software Project Management at the University of Salerno.

Ubiquitous enterprise service adaptations based on contextual user behavior

Recent advances in mobile technologies and infrastructures have created the demand for ubiquitous access to enterprise services from mobile handheld devices. Further, with the invention of new interaction devices, the context in which the services are being used becomes an integral part of the activity carried out with the system. Traditional human---computer interface (HCI) theories are now inadequate for developing these context-aware applications, as we believe that the notion of context should be extended to different categories: computing contexts, user contexts, and physical contexts for ubiquitous computing. This demands a new paradigm for system requirements elicitation and design in order to make good use of such extended context information captured from mobile user behavior. Instead of redesigning or adapting existing enterprise services in an ad hoc manner, we introduce a methodology for the elicitation of context-aware adaptation requirements and the matching of context-awareness features to the target context by capability matching. For the implementation of such adaptations, we propose the use of three tiers of views: user interface views, data views, and process views. This approach centers on a novel notion of process views to ubiquitous service adaptation, where mobile users may execute a more concise version or modified procedure of the original process according to their behavior under different contexts. The process view also serves as the key mechanism for integrating user interface views and data views. Based on this model, we analyze the design and implementation issues of some common ubiquitous access situations and show how to adapt them systematically into a context-aware application by considering the requirements of a ubiquitous enterprise information system.

Context-oriented and transaction-based service provisioning

This paper presents our approach for service provisioning in pervasive computing environments. The presented approach is based on the usage of context-aware features and transactions during the discovery and the deployment of composite services. Context ensures that the best service offers are selected to participate in a service composition. Transactions help in improving the reliability and efficiency of the composite services.

CAMP: a context-aware mobile portal

Context-awareness-enhanced mobile computing is expected to be one of the major ingredients of the future wireless services based on IT technologies. This article proposes the concept of such a modular mobile Internet portal enhanced with context awareness features. Some services built into the portal are explained and the benefit for mobile users analyzed. A functional prototype is presented that has been successfully used as a concept proof.