Video Conferencing Evaluation Considering Scalable Video Coding and SDN Network

Video conferencing is very common nowadays, and it may contemplate heterogenous devices (e.g., smartphones, notebooks, game consoles) and networks in the same session. Developing video conferencing systems for this myriad of devices with different capabilities requires special attention from system designer. Scalable video coding (SVC) is a prominent option to mitigate this heterogeneity issue, but traditional Internet protocol (IP) networks may not fully benefit from such a technology. In contrast, software-defined networking (SDN) may allow better utilization of SVC and improvements on video conferencing components. This paper evaluates the performance of video conferencing systems adopting SVC, SDN and ordinary IP networks, taking into account throughput, delay and peak signal-to-noise ratio (PSNR) as the metrics of interest. The experiments are based on Mininet framework and distinct network infrastructures are also considered. Results indicate SDN with SVC may deliver better video quality with reduced delay and increased throughput

Real Time Conference Gateway For Heterogeneous Clients : Real Time Switching Clients And Inter-Asterisk Exchange Clients

Various standards organizations have considered signaling for voice and video over Internet Protocol(IP) from different approaches. The Inter-Asterisk eXchange (IAX) protocol is used as the promising VoIP protocol by the service provider because of its simplicity and NAT friendliness. Meanwhile, the Real time SWitching (RSW) has the ability to combine voice and video services. Incidentally, these two heterogeneous clients pose considerable problems for users who have to choose between two solutions offering different advantages and disadvantages. While RSW is being used in many areas, IAX is being deployed in many VoIP services. Hence, RSW interoperability and coexistence with IAX is considered very important to support new deployments that could use RSW as an alternative packet telephony signaling protocol. We proposed and implemented the conference gateway (CG), which enables the heterogeneous clients to communicate seamlessly. It has two modules, one is signaling, the other is media module. In signaling module, we have converted signaling and control messages of RSW and IAX respectively to achieve seamless signaling communication between heterogeneous clients via CG. The signaling module includes authentication of heterogeneous clients (RSW and IAX) before they start communication, conversion of Uniform Resource Indicator to reach remote clients, setup media calls and exchange media capability

Convivo communicator : an interface-adaptive voice over IP system for poor quality networks

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2002.Includes bibliographical references (leaves 100-102).This thesis presents Convivo, a VoIP system designed to provide reliable voice communication for poor quality networks, especially those found in rural areas of the developing world. Convivo introduces an original approach to maintain voice communication interaction in presence of poor network performance: an Interface-Adaptation mechanism that suggests adjusting the application user interface to conform to one of three voice communication modalities (full duplex, half duplex, and voice messaging). The thesis proposes that changes in communication modality are an option to sustain voice communication interaction despite poor network performance. The goals of the changes in communication modality are to reduce the impact of high latency and low bandwidth on voice communication interaction, to facilitate turn taking for a high latency connection, and to sustain voice communication for extremely low bandwidth or high error links. The system was tested via a user study in Bohechio, a small village in the Dominican Republic. The study found that Interface-Adaptation helped users to maintain voice communication interaction when network performance degrades. Transitions from full duplex to voice messaging were found particularly valuable. Initial results suggest that as users get more experience with the application they would like to manually control transitions based on feedback provided by the application and their own perceived voice quality.by Marco Antonio Escobedo Gonzalez Maiz.S.M

MediaSync: Handbook on Multimedia Synchronization

This book provides an approachable overview of the most recent advances in the fascinating field of media synchronization (mediasync), gathering contributions from the most representative and influential experts. Understanding the challenges of this field in the current multi-sensory, multi-device, and multi-protocol world is not an easy task. The book revisits the foundations of mediasync, including theoretical frameworks and models, highlights ongoing research efforts, like hybrid broadband broadcast (HBB) delivery and users' perception modeling (i.e., Quality of Experience or QoE), and paves the way for the future (e.g., towards the deployment of multi-sensory and ultra-realistic experiences). Although many advances around mediasync have been devised and deployed, this area of research is getting renewed attention to overcome remaining challenges in the next-generation (heterogeneous and ubiquitous) media ecosystem. Given the significant advances in this research area, its current relevance and the multiple disciplines it involves, the availability of a reference book on mediasync becomes necessary. This book fills the gap in this context. In particular, it addresses key aspects and reviews the most relevant contributions within the mediasync research space, from different perspectives. Mediasync: Handbook on Multimedia Synchronization is the perfect companion for scholars and practitioners that want to acquire strong knowledge about this research area, and also approach the challenges behind ensuring the best mediated experiences, by providing the adequate synchronization between the media elements that constitute these experiences

MULTI-PHOTON TOLERANT QUANTUM KEY DISTRIBUTION PROTOCOLS FOR SECURED GLOBAL COMMUNICATION

This dissertation investigates the potential of multi-photon tolerant protocols for satellite-aided global quantum key distribution (QKD). Recent investigations like braided single-stage protocol and the implementation of the three-stage protocol in fiber have indicated that multi-photon tolerant protocols have wide-ranging capabilities for increasing the distance and speed of quantum-secure communication. This dissertation proposes satellite-based network multicasting and its operation that can profitably use multi-photon tolerant protocols for quantum-secure global communication. With a growingly interconnected world and an increasing need for security in communication, communication satellites at Lower Earth Orbits (LEO), Medium Earth Orbit (MEO) and Geostationary Earth Orbit (GEO) have a potential role in serving as a means to distribute secure keys for encryption among distant endpoints. This dissertation systematically evaluates such a role. The dissertation proposes a layered framework using satellites and fiber optic links that can form a composite system for carrying the information payload and distributing quantum-secure keys for encrypting information in transit. Quantum communications links are currently point-to-point. Considering the concept of global QKD network, there is need for multicast quantum links. Multi casting can be achieved in quantum networks by (a) using multiple wavelengths, or (b) using use specific set of bases. In efforts to develop a composite quantum secure global communication system; this dissertation also introduces the concept of multi-photon tolerant quantum threshold cryptography. The motivation for development of threshold cryptography is that a secret can be encrypted with multiple users and requires multiple users to decrypt. The quantum threshold cryptography is proposed by using idea of multiple bases. This can be considered as step forward towards multiparty quantum communication. This dissertation also proposed layered architecture for key distribution. Concisely, this dissertation proposes the techniques like multicasting in quantum scenario, quantum threshold cryptography to achieve the goal of secured global communication

Low Cost Video For Distance Education

A distance education system has been designed for Nova Southeastern University (NSU) . The design was based on emerging low cost video technology. The report presented the design and summarizes existing distance education efforts and technologies. The design supported multimedia electronic classrooms, and enabled students to participate in multimedia classes using standard telephone networks. Results were presented in three areas: management, courseware, and, systems. In the area of management, the report recommended that the University separately establish, fund, and staff the distance education project. Supporting rationale was included. In the area of courseware, the importance of quality courseware was highlighted. It was found that the development of distance education courseware was difficult; nevertheless, quality courseware was the key to a successful distance education program. In the area of systems, component level designs were presented for a student system, a university host, and a support system. Networks connecting the systems were addressed. The student system was based on widely available multimedia systems. The host system supported up to sixteen participants in a single class. The support system was designed for the development of courseware and the support of future projects in distance education. The report included supporting Proof of Principle demonstrations. These demonstrations showed that low cost video systems had utility at speeds as low as 7. 2 kbps. They also showed that high quality student images were not crucial to the system. The report included three alternate implementation strategies. The initial capability could be operational in 1997. A multi-session, 2000 user system was projected for early in the next century