Boris Moltchanov

ContextML: A light-weight context representation and context management schema

Context representation is a fundamental process in developing context aware systems for the pervasive world. We present a light weight XML based context representation schema called ContextML in which context information is categorized into scopes and related to different types of entities (e.g. user, device). The schema is also applied for encoding management messages in order to allow for a flexible framework supporting gradual plug & play extendibility and mobility. ContextML is tailored to be used for REST-based communication between the framework components. Explanation of the schema is provided with the help of real world examples. Moreover, the European C-CAST testbed is introduced, embracing a variety of context providers and application domains.

A Federated Broker Architecture for Large Scale Context Dissemination

Dissemination of context data from context producing entities to context consuming entities is a fundamental functional task of context aware systems. Broker based approaches have been successfully demonstrated in a number of prototype context-aware systems. With the increase in sensing capabilities of mobile devices, such devices are not merely consumers of context information any more but also have the ability to be \emph{providers} of context gathered through integrated sensors. In such a provider-consumer model, where context dissemination is aided by a central broker, device-broker interaction can become a communication and computation bottleneck in presence of multiple context providers and consumers in mobile devices. In this paper we present a theoretical model for a large scale context-aware system based on a federation of multiple context brokers and discuss the concept of a mobile broker to facilitate the participation of mobile devices in context provision and consumption efficiently. The utilisation of an asynchronous event-based publish-subscribe paradigm is focused as a key element.

Large-scale context-aware system in smart spaces: Issues and challenges

Smart spaces are characterised by availability of information from digital artifacts embedded in the environment and network services that unobtrusively enhance our interaction with the digital world. User and environment context plays a vital role in deciding the usability of information services available in a smart space. Making this context available and coordinating it across the network, geographic and administrative boundaries of individual smart spaces are significant challenges that have not been adequately addressed in existing context-aware systems. We discuss various facets of this challenge and present an architecture based on federation of context brokers for large-scale context dissemination in smart spaces.

Context management and reasoning for adaptive service provisioning

The European research project “C-Cast” (Context-Aware Content Casting) aims at providing an end-to-end system design for context-aware services and content provisioning. The project does not limit itself to reasoning but embraces also efficient service provisioning to user groups detected and formed according to the inferred user context. This paper presents the architecture components related to context acquisition through the reasoning and context management. It presents a framework for modular multi domain context detection and shows how required context can be obtained by acquiring a variety of source data and applying reasoning mechanisms for aggregation. The raw data can originate from virtual, logical or physical sensors, covering the physical environment of the user, profile information and other databases (e.g. calendar, address book). Based on the derived context, content or service provisioning can be adapted in order to reduce need for explicit feedback and to increase the overall user experience. Due to the extensive dynamics in a mobile environment and rapid context changes, event-based reasoning is applied, ensuring efficiency and scalability. Furthermore, a user interface for easy and fast extension of the context model is introduced.

Multi-level Adaptations in a CloudWave Infrastructure: A Telco Use Case

CloudWave is a FP7 EU project whose aim is delivering novel technologies and methods for improving both the development of Cloud services and the management of their operation and execution. Such goal is reached by providing mechanisms and policies for coordinating multiple adaptations both at the level of the Cloud infrastructure and at the level of the hosted applications. In this paper, we describe the CloudWave Telco application use case and we provide a proof of concept discussing how the QoS experienced by the application users can be improved thanks to the technologies provided by CloudWave.

Linked Data-Driven Smart Spaces

In this paper, we present an approach to exploit Linked Data in Smart Spaces, doing more than just using RDF to represent information. In particular, we rely on knowledge stored in DBpedia, a dataset in the Web of Data. We also provide a platform to implement such an approach and a eTourism use case, both developed in collaboration with a mobile operator. Finally, we provide also a performance evaluation of the main component of the platform.

The effect of biased choice of peers on quality provided by P2P file sharing

The positive effect of traffic localization in P2P systems is widely praised as it allows to decrease the amount of traffic crossing inter-ISP links. At the same time its negative effect is often overlooked. In this paper we concentrate on the biased choice of peers as a way to localize traffic in P2P BitTorrent-like file sharing systems. We demonstrate, evaluate and discuss the negative effect of traffic localization expressing itself in the increase of the average file downloading time as the level of localization increases.

Smart Space Governing through Service Mashups

The rapid and constant evolution of Smart Spaces has introduced an increase in the complexity and quantity of its components, making the monitoring and management processes more challenging and complex. On the other hand, Service Mashups enable the design and development novel and modern Web applications based on easy-to-accomplish end-user service compositions.

Enabling new generation cloud services with coordinated adaptation

Despite the technological advances of IT Clouds, few efforts have been dedicated to assist the cloud application and services developers during the creation process, that goes from the development to the execution phase with the adaptation of the behavior and the optimized allocation of system resources. The CloudWave EU project, has the objective of contributing to these underdeveloped concepts by introducing a Feedback-Driven Development (FDD) approach during the development and a Coordinated Adaptation (CA) concept to control the execution by adapting the application or service behavior and its cloud environment accordingly to the execution context and condition changes. This paper describes the CloudWave concept as well as its architecture. Similarly, the initial implementation of the project is detailed. Additionally, it is shown how the project can be implemented in the Telco sector and the benefits and advantages that it offers.

Cloud Wave Smart Middleware for DevOps in Clouds

Nowadays the IT Clouds are used to provide services and run applications (in a flexible and scalable way) where the entire lifecycle of the application or service is under the control of the Cloud Management Subsystem that is able to automatically and autonomously start, stop, restart a server or an application. Additionally, it is able to determine when a certain application or service is running under overload conditions and reduce the load by adding additional virtual machines hosting the affected software or releasing the resources not used anymore. These are classic operations performed by nowadays Clouds. However little effort has been dedicated to support a developer during the application development process or during the service execution by changing the application behavior dependently on the services components response and availability. The Cloud Wave project founded by the European Commission within the FP7 Research Program aims to contribute on these underdeveloped concepts. It contributes to the development process of a service or application in a feedback-driven way and also to the service execution by adapting the service accordingly to the execution environment and condition changes.