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Enabling Adaptive Context Views for Mobile Applications: Negotiating Global and Dynamic Sensor Information
Mid Sweden University, Faculty of Science, Technology and Media, Department of Information Technology and Media.
2011 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Mobile devices with Internet access and large amounts of sensors, pushes the development of intelligent services towards new forms of pervasive applications. These applications are made context-aware by utilizing information from sensors and hence the context of a situation, in order to provide a better service. Based on this, the focus of this thesis is on the challenge of creating context awareness in mobile applications. That both utilizes dynamic context information from globally available sensors and provides adaptive views of relevant context information to applications.

The first challenge is to identify the properties of an architecture that provides scalable access to information from global sensors within bounded time, because existing systems do not support these properties in a satisfactory manner. The majority of related systems employ a centralized approach with limited support for global sensor information due to poor scalability. Therefore, this thesis proposes a distributed architecture capable of exchanging context between users and entities on a peer-to-peer overlay. Pervasive applications can thus utilize global sensor information in a scalable and manageable way within predictable time bounds.

The second challenge to support continually changing and evolving context information, while providing it as both adaptive and manageable views to applications. To address this particular problem, this thesis proposes the usage of a locally stored evolving context object called a context schema. In detail, this schema contains all context information that is considered as being relevant for a specific user or entity. Furthermore, this thesis proposes an application interface that can provide snapshots of the evolving context schemas as adaptive views. These views can then be used in context-aware mobile applications, without inducing unnecessary delays.

By successfully addressing the challenges, this thesis enables the creation of pervasive and adaptive applications that utilize evolving context in mobile environments. These capabilities are made possible by enabling access to global sensor information based on a distributed context exchange overlay, in combination with evolving context schemas offered as views through an application interface. In support of these claims, this thesis has developed numerous proof-of-concept applications and prototypes to verify the approach. Hence, this thesis concludes that the proposed approach with evolving context information has the ability to scale in a satisfactory manner and also has the ability to dynamically offer relevant views to applications in a manageable way.

Place, publisher, year, edition, pages
Sundsvall: Mittuniversitetet , 2011. , 68 p.
Series
Mid Sweden University licentiate thesis, ISSN 1652-8948 ; 58
Keyword [en]
Context, Sensors, Mobile applications
National Category
Computer Science
Identifiers
URN: urn:nbn:se:miun:diva-13919Local ID: STCISBN: 978-91-86694-36-4OAI: oai:DiVA.org:miun-13919DiVA: diva2:420700
Opponent
Supervisors
Projects
MediaSense
Available from: 2011-06-03 Created: 2011-06-03 Last updated: 2016-10-19Bibliographically approved
List of papers
1. Location-Based Ubiquitous Context Exchange in Mobile Environments
Open this publication in new window or tab >>Location-Based Ubiquitous Context Exchange in Mobile Environments
2010 (English)In: Lecture Notes of the Institute for Computer Sciences Social Informatics and Telecommunications Engineering Vol 68, Springer, 2010, 177-187 p.Conference paper (Refereed)
Abstract [en]

Context-aware applications and services require ubiquitous access to context information of users. The limited scalability of centralized servers used in the provisioning of context information mandates the search for scalable peer-to-peer protocols. Furthermore, unnecessary signaling must be avoided in large-scale context networks, when location-based services only require nodes in a certain area with which to communicate context. To this end, we propose a lightweight model for composing and maintaining unstructured location-scoped networks of peer-to-peer nodes, which gossips in order to ensure quality of service for each user. The model is implemented in a prototype application running in a mobile environment, which is evaluated with respect to real-time properties. This model can also be extended to include more context dimensions, other than location.

Place, publisher, year, edition, pages
Springer, 2010
National Category
Computer Science
Identifiers
urn:nbn:se:miun:diva-12280 (URN)000307366900016 ()2-s2.0-84870673461 (ScopusID)
Conference
Monami 2010
Available from: 2010-11-24 Created: 2010-11-24 Last updated: 2015-03-17Bibliographically approved
2. Dissemination of Anonymised Context Information by Extending the DCXP Framework
Open this publication in new window or tab >>Dissemination of Anonymised Context Information by Extending the DCXP Framework
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2010 (English)In: Lecture Notes of the Institute for Computer Sciences Social Informatics and Telecommunications Engineering Volume 32, Springer, 2010, 57-66 p.Conference paper (Refereed)
Abstract [en]

The increasing ubiquity of context aware services and systems has been primarily underpinned by the use of centralised servers employing protocols that do no scale well for real time distribution and acquisition of neither sensor data nor dependent services.Any shift from this generic sensor framework mandated a new thinking where sensor data was capable of being propagated in real time using protocols and data models which serve to reduce unnecessary communication overhead. DCXP is proposed as an alternative architecture for the real time distribution of context information to ubiquitous mobile services.As a P2P based distributed protocol, it inherently poses the challenge of user anonymity across the system. In this paper we briefly present DCXP along with further work to enable the anonymised dissemination of sensor information within the architecture.Such a solution would have a negligible impact on the overall scalability and performance of DCXP.

Place, publisher, year, edition, pages
Springer, 2010
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-9948 (URN)000303422100006 ()2-s2.0-84885884773 (ScopusID)
Conference
First International ICST Conference on Mobile Networks And Management
Available from: 2009-09-30 Created: 2009-09-30 Last updated: 2016-09-22Bibliographically approved
3. Distributed Context Support for Ubiquitous Mobile Awareness Services
Open this publication in new window or tab >>Distributed Context Support for Ubiquitous Mobile Awareness Services
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2009 (English)In: 2009 Fourth International ICST Conference on Communications and Networking in China. ChinaCom'09., IEEE conference proceedings, 2009, 869-873 p.Conference paper (Refereed)
Abstract [en]

Context-aware applications and services require ubiquitous access to context information about the users or sensors such as preferences, spatial & environmental data, available connectivity, and device capabilities. Systems for the brokering or the provisioning of context data via wireless networks do so with centralized servers or by employing protocols that do not scale well with real-time distribution capabilities. In other cases, such as the extending of presence systems, the data models are limited in expressive capabilities and consequently incur unnecessary signaling overhead. This paper presents a distributed protocol, the Distributed Context eXchange Protocol (DCXP), and an architecture for the real-time distribution of context information to ubiquitous mobile services: We present the architecture and its principle operation in a sample ubiquitous mobile awareness service. Preliminary results indicate that our approach scales well for the ubiquitous provision of context data in real-time to clients on the Internet via 3G wireless systems. Performed measurements show that DCXP can reduce the time to process context data with a factor of 20 compared to similar approaches.

 

Place, publisher, year, edition, pages
IEEE conference proceedings, 2009
Keyword
3G wireless; Centralized server; Context aware applications; Context data; Context information; Data models; Distributed protocols; Environmental data; Exchange protocols; Mobile awareness; Mobile service; Time distribution; Ubiquitous access, Internet protocols; Network architecture; Network protocols; Real time systems; Wireless networks; Wireless telecommunication systems
National Category
Computer Science
Identifiers
urn:nbn:se:miun:diva-9669 (URN)10.1109/CHINACOM.2009.5339728 (DOI)2-s2.0-71749111713 (ScopusID)978-1-4244-4337-6 (ISBN)
Conference
2009 4th International Conference on Communications and Networking in China, CHINACOM 2009; Xian; 26 August 2009 through 28 August 2009; Category number CFP0970A; Code 78908
Available from: 2009-09-17 Created: 2009-09-17 Last updated: 2013-03-23Bibliographically approved
4. Ubiquitous Mobile Awareness from Sensor Networks
Open this publication in new window or tab >>Ubiquitous Mobile Awareness from Sensor Networks
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2009 (English)In: Lecture Notes of the Institute for Computer Sciences Social Informatics and Telecommunications Engineering Volume 12, Springer, 2009, 147-150 p.Conference paper (Refereed)
Abstract [en]

Users require applications and services to be available everywhere,enabling them to focus on what is important to them. Therefore, contextinformation (e.g., spatial data, user preferences, available connectivity anddevices, etc.) has to be accessible to applications that run in end systems closeto users. In response to this, we present a novel architecture for ubiquitoussensing and sharing of context in mobile services and applications. Thearchitecture offers distributed storage of context derived from sensor networkswirelessly attached to mobile phones and other devices. The architecture alsohandles frequent updates of sensor information and is interoperable withpresence in 3G mobile systems, thus enabling ubiquitous sensing applications.We demonstrate these concepts and the principle operation in a sampleubiquitous Mobile Awareness service.

Place, publisher, year, edition, pages
Springer, 2009
National Category
Computer Science
Identifiers
urn:nbn:se:miun:diva-9949 (URN)000302334000018 ()2-s2.0-84885888176 (ScopusID)
Conference
Workshops on Mobile Wireless Middleware, Operating Systems, and Applications, Mobilware 2009; Berlin; Germany; 28 April 2009 through 29 April 2009
Available from: 2009-09-30 Created: 2009-09-30 Last updated: 2016-09-23Bibliographically approved
5. The MediaSense Framework
Open this publication in new window or tab >>The MediaSense Framework
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2009 (English)In: Proceedings - 2009 4th International Conference on Digital Telecommunications, ICDT 2009, New York: IEEE conference proceedings, 2009, 144-147 p.Conference paper (Refereed)
Abstract [en]

Mobile telecommunication is evolving rapidly. People no longer only communicate with each other regardless of time and place, but also share other information that is important for tasks with which they are involved. In response to this growing trend the MediaSense framework addresses the intelligent delivery of any information to any host, anywhere, based on context-aware information regarding personal preferences, presence information, and sensor values. This includes another challenge to achieve seamless delivery, especially of multimedia content, and multimodal services via heterogeneous connections.

Place, publisher, year, edition, pages
New York: IEEE conference proceedings, 2009
National Category
Computer Science
Identifiers
urn:nbn:se:miun:diva-9662 (URN)10.1109/ICDT.2009.34 (DOI)000274805500029 ()2-s2.0-70449561027 (ScopusID)978-0-7695-3695-8 (ISBN)
Conference
2009 4th International Conference on Digital Telecommunications, ICDT 2009; Colmar; 20 July 2009 through 25 July 2009
Projects
MediaSense
Available from: 2009-09-17 Created: 2009-09-17 Last updated: 2013-03-23Bibliographically approved

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