Dr Gabriel-Miro Muntean writes about his research into improving our experience of receiving complex multimedia over diverse wireless networks.
The latest wireless network technologies and mobile devices enable user access to rich media services almost anywhere, any time, and from a wide range of devices.
The network environment that enables this service access is composed of individual networks, which are supported by different technologies, and have various coverage areas and diverse ownerships.
The resulting wireless network environment combines legacy and latest standards for wireless broadband, and different generation solutions for cellular communications. These solutions differ widely in terms of coverage areas and communication speeds.
Apart from technology, these networks also differ in terms of network load, support for mobility, cost etc. Most importantly, none of them alone can offer the comprehensive support required by the wide range of current and future rich-media user services.
Top international researchers have put in a significant effort to bridge these heterogeneous wireless networks while maintaining ‘always-best connectivity’ for the mobile users.
My team at the Performance Engineering Laboratory at Dublin City University go a step further and propose innovative solutions towards achieving ‘always-best experience’ for the users. This is because ‘best connectivity’ may have different meanings for different classes of users, in the context of diverse services and in relation to various devices.
User profile, service requirements, device properties, as well as network dynamic characteristics, are factored into these solutions, which are based on optimum network selection in this heterogeneous wireless network environment.
Among others, theoretical research, architectural design, modelling, simulations, prototyping and comparative performance data analysis are involved in the process of proposing these solutions.
At the same time, devices are getting smaller, more sophisticated and are capable of running more complex applications. There is also a natural desire from users to access richer services with a wide range of features. Multimedia applications are playing an increasingly significant role in these developments.
Rich media gets richer
However, there are many difficulties when performing wireless multimedia delivery to mobile users in the current heterogeneous wireless network environment. These difficulties are mostly due to factors including limitations and variability of bandwidth, variability and level of loss, limited device battery power and cost.
Researchers worldwide propose adaptive solutions, which adjust multimedia delivery to network conditions and device characteristics.
At the Performance Engineering Lab, we perform research and propose solutions to tailor the wireless multimedia transmissions; not only to device properties and network conditions, but also based on battery power levels, user interest in content, user mobility pattern and existing budget, in order to maximise user-perceived quality for the chosen service in the given delivery environment.
Our recent research includes proposals of innovative delivery solutions for 3D multimedia content and multiple sensorial media (mulsemedia) services, which involve multimedia content enhanced with components such as olfaction and wind, for example.
‘Our research includes proposals for 3D multimedia content and ‘mulsemedia’ services, which involve multimedia content enhanced with components such as olfaction and wind’
A measure of quality
It is also important to evaluate the delivery of the rich media services in the heterogeneous wireless network environment.
Quality of service (QoS) metrics are often used to assess the success of a service, but they are poorly correlated with user-perceived quality and, therefore, researchers propose and use diverse quality of experience (QoE) metrics, with limited accuracy.
We are also looking at proposed novel solutions to evaluate the user-perceived quality of both 2D and 3D video content delivered over the networks, subject to diverse variable conditions.
Dr Gabriel-Miro Muntean is a senior lecturer in the School of Electronic Engineering at Dublin City University and co-director of the university’s Performance Engineering Laboratory. Muntean and his team are contributing to the effort of providing seamless access to rich media services at high quality, despite the heterogeneity of the current and future network environment.