Context-aware Multimedia Services Research Articles

Optimal Beam Steering for Maximal Visual Quality Over a Multimedia Broadcasting System

Various types of multimedia services have become prominent over the last few years leading to difficulty in providing high-quality broadcast multimedia services in certain shadowing regions without resource management in accordance with specific channel adaptation. In order to overcome this difficulty, return channel design has been actively discussed in broadcasting standards for broadcasting systems. Context-aware multimedia services have been developed by adapting radio resources according to service type. In order to forward this goal, we propose a beamforming technique to optimize spatial resources in order to maximize visual quality for video broadcasting services. In order to enhance the video broadcast service, we derive expected visual information (EVI) that quantifies the visual quality of video and adapt the EVI into multiple-input and multiple-output beamforming techniques in a video broadcast system. In order to guarantee the proportional fairness of broadcast users, we propose a novel beam steering algorithm using the log-EVI sum maximization, and compare it to the traditional channel-quality-based max–min problem. The beam-steering algorithm is performed iteratively while switching the bases, which constructs a beam steering weight vector domain. In the simulation, we demonstrate that the proposed algorithm has less computational complexity than conventional algorithms, and the visual quality of the proposed algorithm is enhanced over that of the traditional quasi-optimal max–min fairness algorithm.

Context-aware multimedia services modeling: an e-Health perspective

In this paper we present an e-Health framework model that can dynamically provide context-aware multimedia services to a user. The framework collects live user context by analyzing sensory data obtained from a body sensor network and multimedia content available from live heterogeneous Internet-based services. Finally, we share the implementation details and test results.

Development of portable intelligent gateway system for ubiquitous entertainment and location-aware push services

Intelligent gateway systems have evolved to seamlessly offer location-aware and multimedia services, allowing multi users to roam among multi service domains. In the past decade intelligent gateways have been implemented to support context-aware multimedia services with network convergence and service reasoning mechanisms in multi domains. However, recent researches have to consider multiple events and service management according to the user's movements and requirements. Therefore, we propose a Portable Intelligent Gateway System (PIGS) to offer seamless device-independent multimedia services and location-aware push services. Using heterogeneous network convergence and utilizing cooperation between other gateways, the PIGS interconnects users (user devices) who want to be offered multimedia services and Service Providers (SPs). Furthermore, our system dynamically offers differential services to multiple users with respect to the user, device and location characteristics. The PIGS also collects events using embedded sensors and generates events used for service configuration along with service predictions by using light-weight middleware. In this paper we implement real testbed, a house and a car, and verify the effectiveness of the service reconfiguration. The portable gateway structure using the PIGS achieves a 22% faster service response time in comparison to a fixed gateway-based structure.

Framework for managing context-aware multimedia services in pervasive environments

This paper presents the CONTEXT framework for the creation, deployment and management of context-aware multimedia services using programmable network facilities. The Service Creation Layer (SCL) components of this framework allow the creation of the services using a service subscription server. Customisation and management are both supported by the policy-based paradigm. The Policy-Based Service Management (PBSM) layer components ensure efficient delivery and management of these services and the Execution Layer components guarantee the correct execution and assurance of the context-aware multimedia services over the network.

Information modeling and handling for context-aware multimedia services

This article presents research challenges in wireless ad hoc networks supporting context-aware multimedia services from the point of view of different context-modeling approaches and a system architecture for context handling and delivery. Modeling techniques for context information are classified into six different categories and benchmarked according to their support with regard to 12 service requirements described in this work. One of these modeling techniques is used in the framework of a distributed context handling and delivery system that is also part of this article's contribution and a representative wireless ad hoc application scenario is presented. This end user scenario and many others are possible thanks to the flexibility and adaptability of the above mentioned context handling and delivery system

An OSGi-based infrastructure for context-aware multimedia services

This article proposes an OSGi-based infrastructure for context-aware multimedia services in a smart home environment. A context-aware multimedia middleware (CMM), which supports multimedia content filtering, recommendation, and adaptation according to changing context is presented. It also performs context aggregation, reasoning, and learning. To foster device and service interoperability, CMM is integrated with an OSGi service platform. We envisage the OSGi-based infrastructure to fill the niche of three gateways in a smart home: network connecting, context provisioning, and multimedia personalizing.