Asimakis Lykourgiotis

Hybrid broadcast and broadband networks convergence for immersive TV applications

This article proposes a converged broadcast and broadband platform in order to deliver 3D media to both mobile and fixed users with guaranteed minimum quality of experience (QoE). The work presented offers an ideal business model for operators having both digital video broadcast and Internet Protocol (IP)-based media services. To that end, the DVB and peer-to-peer Internet technologies will be combined to provide sufficient resources for supporting high-bandwidth high-quality 3D multiview video. The motivations behind combining these technologies are outlined with an emphasis on their complementary characteristics. In addition, the overall design of the proposed architecture is presented focusing on the protocols that are exploited to achieve the interworking of the underlying technologies. Moreover, innovative key techniques for supporting both fixed and mobile users in an efficient manner are introduced.

An media aware platform for real-time stereoscopic video streaming adaptation

Stereoscopic video streaming is emerging as an important technology for future multimedia services. The delivery of real-time high quality three dimensional video to consumers remains a significant challenge due to the scarce resources of the access networks. While real-time rate adaptation has been proposed as a straight forward and easy to deploy method of minimizing transmission losses, its impact on the perceived three dimensional video quality is yet to be studied in depth. This paper investigates the impact of Media Aware Network Element (MANE) on the perceived quality of stereoscopic video measured by Peak Signal to Noise Ratio (PSNR) to both views. Instead of losing packets randomly during the video transmission, the proposed scheme selectively drops packets of the enhancement layers form both views, minimizing the distortion of both views. The Double Exponential Smoothing mechanism is selected for forecasting the transmission data rate. The experimental results indicate that by applying the proposed adaptation scheme, there is a significant improvement on the objectively measured quality of the received video.

EMYNOS: Next Generation Emergency Communication

Current emergency systems and 112 services are based on legacy telecommunication technologies, which cannot cope with IP-based services that European citizens use every day. Some of the related limitations are partial media support, the lack of integration of social media, and the use of an analog modem for providing eCall services with limited data amounts. As most operators have started migrating toward broadband IP-based infrastructures, current emergency systems also need to be upgraded and adapted in order to fulfill regulatory requirements in terms of next generation emergency services. This article presents the EMYNOS project, the goal of which is the design and implementation of a next generation platform capable of accommodating rich-media emergency calls that combine voice, text, and video, thus constituting a powerful tool for coordinating communication among citizens, call centers, and first responders. Additionally, issues such as call routing/redirection to the closest available call center, retrieval of caller location, support for people with disabilities, and integration of social media are detailed.

A Framework for QoE-Aware 3D Video Streaming Optimisation over Wireless Networks

The delivery of three-dimensional immersive media to individual users remains a highly challenging problem due to the large amount of data involved, diverse network characteristics, and user terminal requirements, as well as user’s context. This paper proposes a framework for quality of experience-aware delivering of three-dimensional video across heterogeneous wireless networks. The proposed architecture combines a Media-Aware Proxy (application layer filter), an enhanced version of IEEE 802.21 protocol for monitoring key performance parameters from different entities and multiple layers, and a QoE controller with a machine learning-based decision engine, capable of modelling the perceived video quality. The proposed architecture is fully integrated with the Long Term Evolution Enhanced Packet Core networks. The paper investigates machine learning-based techniques for producing an objective QoE model based on parameters from the physical, the data link, and the network layers. Extensive test-bed experiments and statistical analysis indicate that the proposed framework is capable of modelling accurately the impact of network impairments to the perceptual quality of three-dimensional video user.

A stereo client using open SVC decoder extensions: QoE performance evaluation

This paper presents a stereo client within an end-to-end video communication ecosystem. The key characteristics of the stereo 3D Client are the following: “Open SVC Decoder” extensions to handle and parse on-the-fly RTP flows for both streams (Left-Right View), dynamic jitter buffer management, 3D Synchronization between the two views and Error concealment. QoE measurements have been carried out to evaluate the robustness of the Client within an end-to-end video communication platform. It is shown that stereo video quality is substantially higher when using the error concealment techniques.

On optimizing scalable video delivery over media aware mobile clouds

The sovereignty of cloud-deployed media applications and services is improbable to be disrupted in the foreseeable future. This paper aims to provide an overview of the most essential technologies utilized by this constantly evolving cloud ecosystem, identify the design principles of a media-aware cloud and present an architectural position based on the research conclusions. An end-to-end quality-aware optimization framework is evaluated, where path selection mechanisms are exploited in conjunction with media optimization in order to support cloud based multimedia delivery in a quality-aware manner. This position intends to be simplistic yet outright enough to be employed for mobile cloud deployment in the upcoming fifth generation network era.

Efficient Next Generation Emergency Communications over Multi-Access Edge Computing

Traditionally, emergency communications between citizens and public authorities relied on legacy telecommunication technologies unable to cope with the agile, rich-media-content communications that mobile users are already using. This is due to the lack of harmonization and interoperable IP-based networking solutions. With the operators currently migrating to broadband IP infrastructures, emergency systems also need to follow this path and adapt their emergency communication platforms to fulfill next generation emergency services regulatory requirements. This becomes even more evident in light of the forthcoming 5G networks, which are envisioned to support an amalgam of diverse applications and services with heterogeneous performance requirements, including mission-critical IoT communication, massive machine-type communication, and gigabit mobile connectivity. Emergency service operators face an enormous challenge in order to synchronize their model of operation with the 5G paradigm. This article studies the challenges that next generation emergency services need to overcome in order to fulfill the requirements for rich-content, real-time, location-specific communications. The concept for next generation emergency communications as described in the project EMYNOS is presented, along with a vision of how this concept can fulfill the 5G requirements for ultra-reliable and ultra-low-latency emergency communications.

A Novel Mobility-Aware Playout Algorithm for VoIP Services

The latest explosive growth in mobile networks has resulted in an increasing interest in optimisation techniques for mobile services. Resent advances in mobile wireless networks incorporate link-layer intelligence in order to enhance the performance of network and application layers. The Media Independent Handover (MIH) standard provides a framework that can make such link-layer intelligence available to upper layers. In this paper, a novel MIH-enabled playout algorithm for Voice over Internet Protocol applications is presented that aims to compensate for the degradation of voice quality caused by handovers. To that end, link-layer triggers in conjunction with speech time-scale modification techniques are exploited to mitigate the increase in delay and jitter induced by the handover process. Results of subjective listening tests show typical gains of 0.3 on a 5-point scale of the Mean Opinion Score with respect to existing playout scheduling schemes.

Secure and interoperable communication infrastructures for PPDR organisations

The growing number of events affecting public safety and security (PS&S) on a regional scale with potential to grow up to large scale cross border disasters puts an increased pressure on agencies and organisation responsible for PS&S. In order to respond timely and in an adequate manner to such events, Public Protection and Disaster Relief (PPDR) organisations need to cooperate, align their procedures and activities, share the needed information and be interoperable. Existing PPDR/PMR technologies such as TETRA, TETRAPOL or P25, do not currently provide broadband capability nor is expected such technologies to be upgraded in the future. This presents a major limitation in supporting new services and information flows. Furthermore, there is no known standard that addresses interoperability of these technologies. In this contribution the design of a next generation communication infrastructure for PPDR organisations which fulfills the requirements of secure and seamless end-to-end communication and interoperable information exchange within the deployed communication networks is presented. Based on Enterprise Architecture of PPDR organisations, a next generation PPDR network that is backward compatible with legacy communication technologies is designed and implemented, capable of providing security, privacy, seamless mobility, QoS and reliability support for mission-critical Private Mobile Radio (PMR) voice and broadband data services. The designed solution provides a robust, reliable, and secure mobile broadband communications system for a wide variety of PMR applications and services on PPDR broadband networks, including the ability of inter-system, interagency and cross-border operations with emphasis on interoperability between users in PMR and LTE.

Modeling 3D video user experience forwireless networks

Recently the entertainment industry, the multimedia content providers and the research community have been experiencing the decisive introduction and evolution of three-dimensional (3D) imaging. This far more complex and sophisticated than the traditional 2D technology raises the major problem of how users perceive quality of 3D video. This paper studies user experience for 3D video streaming that takes into account the spatial and temporal information of the video, the resolution, the quantization step size, as well as, wireless network related parameters from the physical, the data link and the network layers. The purpose of this study is to analyze the impact of each of these key performance indicators in order to efficiently model 3D video user experience in wireless networks. Such a model can be exploited by network selection algorithms so as to accurately predict user experience based on these indicators.