We implement the ¡§Internet Video Conference System¡¨ based on ITU-T H.323 multimedia communication protocols standard in paper. This part, we discuss the H.323 protocols how to work on the Internet and analysis the network structure on the video conference system. Development of the system will consider network structure restrict, user habits and system integrate problem. We are not development the point-point communication, but also development multipoint communication by the multicast concept. To solve the distance and capacity problem on video conference, we research the ¡§Zone Switching¡¨ and ¡§Multi-MCU¡¨ structure this paper. We analysis the performance of the video conference system by the new structure, it includes ¡§switching structure of the different Zone¡¨ and ¡§switching structure of the same Zone¡¨. Finally, we analysis the performance and work on the Internet by the new structure.

With the progress of the network, peoples can communicate with each other easily. The popularization of the Broadband network makes many things that could be hard to achieved becoming possible. For example, video conference, distance education and on-line games have become a part of our daily life. However, most network services are client-server architecture. This kind of service need a expensive and powerful server. The restriction will makes it difficult to improve the quality of service. P2P (peer-to-peer) architecture embodies one of the key technical concepts of the internet and many internet users was attracted by it. A peer-to-peer computer network is a network that relies on computing power at the edges (ends) of a connection rather than in the network itself. It has been used in two kinds of applications which are file sharing and distributed computing. Instead of using P2P model, client-server architecture is used in muti-user conference. A software using P2P model still needs one of the users to become a server to deal with all the messages in the conference. When the number of the users increasing, the overhead of the server will increase linearly. This makes many communication softwares to limit the number of users in a conference. Therefore, most of the companies use an expensive and powerful server offering this kind of service. In this paper, we will implement a voice-conferencing system using P2P model and the technique of distributed computing. It makes the overhead of the server in logarithmic increase. In addition, we still can configure some low-end peers with a constant overhead. No mater how the number of users increase, these peers will have a constant overhead. With the good design, we can gurantee the quality of service easily.

The lack of a real English environment in Taiwan and big class teaching had long limited the opportunities for Taiwanese English learners to use English. Due to thriving development of internet technology in recent years, the predicament has been broken through. Internet not only opens a new communicational channel for teachers and students, but also creates an authentic environment for English learners. As the new curriculum policy ¡§coherence curriculum of civil education¡¨, which emphasizes on setting information instruction into each subjects, is taken into practice, learning English with internet tools must will become a trend in the future. Therefore, this research examines the distance between the ideal and the reality using an internet-based English teaching project, and probe into some feasible ways to conduct similar program in the future. There were four purposes of this research: 1. To find out the key factors of success in internet-based English teaching from relative theories and former researches. 2. To understand the teacher¡¦s and students¡¦ performances and the students¡¦ reflections during the first half year joining an internet-based English teaching project. 3. To probe into the merits and defects of the internet-based English teaching project, AJET. 4. To discover the difficulties and feasible ways for senior high schools to carry out internet-based English teaching. The subjects of this research were a senior high school class and their teacher who first joined an internet-based English teaching project named ¡§Advanced Joint English Teaching¡¨ (AJET) in Kaohsiung. All 44 students were male. During the research period, they participated in six internet-based teaching activities, which were ¡§group e-mailing,¡¨ ¡§web-based course,¡¨ ¡§e-mail writing program,¡¨ ¡§English homepage design,¡¨ ¡§video conference¡¨ and ¡§chatroom discussion.¡¨ The researcher traced the students¡¦ performances and collected their work pieces mainly through e-mail, AJET homepage and telephone during the research period. A questionnaire was given to elicit relevant information on the participants¡¦ perception of, and attitudes towards, using the internet technology to complete their Internet-based English projects. Follow-up interview with 10 students and 2 teachers were also collected at the end of the research to understand their reflections on the project. In addition, the students¡¦ performances at the second homepage contest were also recorded. After data collection, the quantitative and qualitative methods were performed. The quantitative statistic analysis was employed using descriptive analysis to investigate the learners¡¦ perceptions towards the Web-based project. The qualitative analysis made from the student responses to the open-ended questions and the researcher¡¦s observation, provided the opportunity to uncover deeper issues than might have been apparent in a quantitative study. Students¡¦ responses to the open-ended questions were broken down into excerpts, where each excerpt represented one complete answer to a question, including any follow-up questions or clarification by student interviews. The main findings and conclusions of this research are as follows: 1. The students¡¦ participation and interaction were not good, and need the teacher¡¦s supervision to help them to form active learning habits. 2. The teacher was overloaded in the project and found it difficult to do both administration and teaching. There is a need of others¡¦ coordination. 3. The students liked and approved of English learning through internet, but differed in their opinions about its benefits to English learning. 4. The project provided the students an opportunity to experience new technologies, felt the pleasure of learning and increased their learning possibilities. 5. To carry out an internet-based English project, the project must spread relative concepts, consider the teacher¡¦s and students¡¦ loads, design each activity with proper number of participants, conduct relative training, and enhance the equipment and communicational efficiency. To sum up, although there is a distance between the ideal and the reality in the internet-based English teaching project, this way of English teaching is worth developing and expanding. Finally, according to the findings of this research, the researcher provides some suggestions for future organizations, teachers and researchers who are interested in this field.

Nowadays the Learning Management System (LMS) platforms provide limited bidirectional, interactive mechanisms that they are competent to handle personal or small-scale distance learning systems. These mechanisms are designed for one to many online tutorials, and the technology utilizes single-input by single-output video stream technology, the video and audio data need to be coupled with one or many Multipoint Control Units (MCU) to mix or convert them into a single output media stream. In this platform MCU is critical to LMS, however, such system is expensive, lack of capacity and difficult to be massively deployed. Access-Grid (AG), an Open Source program, offers users capability to watch online multimedia audio-video contents from all the interconnected nodes of LMS through Multicast protocol, and supports groups-to-group high quality interactive distance learning. It requires all the networks to support the Multicast protocol. The MBONE (Multicast Backbone) can be used to connect different Multicast groups via Unicast communication. However, if the number of groups involving in the distance learning are large, the host computers or routers of the network will be heavily loaded because they need to handle the delivering of the media packets. To use a QuickBridge for aggregating and delivering packages is an alternative of LMS and requires (N-1) *N *BW bandwidth . For example, if there is a 15 nodes online conference and each node uses 800kbps data rate to transmit audio-video contents, then the demanded bandwidth of the aggregation is 168 Mbps. The way of dispersing and controlling the data flow becomes important factors and will greatly affect the quality of the AG online conference. This thesis modifies the procedure of AG and QuickBridge, and allows all the AG Clients to be able to transmit Unicast and Multicast packets in the online conference. It offers a Meeting Management Server to dynamically adjust topology and hub points, and achieves better elasticity to the system. By modifying VIC and RAT procedure, the system controls the outbound audio-video data flow from each nodes of online conference, and reduces the demand of bandwidth. The system can directly provide end-to-end conferencing, using Unicast communication to connect the nodes in different Multicast groups, or using the Multicast on the backbone and then using unicast communication to the local nodes. The functionality of the LMS can be improved and capable of supporting multi-windows to multi-user interactive online conference for the users. The results of this thesis can be applied upon real-time interactive distance learning, online video conferencing and interactive online TV. It also helps to lower the cost of the system and reduce the requirement of network bandwidth.

Dagens informationssamhälle, erbjuder nya sätt att interagera, att etablera relationer och att bibehålla kontakten mellan människor.Teknologi och terapi blir ett sätt att upprätthålla en terapeutisk relation med hjälp av Skype som informationsteknologiskt hjälpmedel. Syftet med studien är att undersöka psykoterapeuters upplevelser avden terapeutiska relationen inom psykodynamisk psykoterapi via videokommunikation. Frågeställningarna fokuserar på terapeuternas användning av de psykodynamiska teorierna, beskrivning av den terapeutiska relationen samt hur den terapeutiska alliansen byggs vid videokommunikation. Studien hade en kvalitativ forskningsansats med en hermeneutisk metod. Sex terapeuter som bedrev terapi på Skype harintervjuats. Resultaten visar att terapeuterna upplevde att det fanns en distans i relationen som kunde användas positivt för att utreda något djupare i terapin. Terapierna blev mer ordrika då överföringaroch motöverföringar inte kunde identifieras lika lätt som vid ett fysiskt möte. Den terapeutiska alliansen upplevdes skörare på Skype. Slutsatser av studien var att bedriva en psykodynamisk psykoterapi på Skype behövde terapeuterna anpassa teorin till teknologin. Distansen irelationen användes som ett hjälpmedel för att terapin skulle utvecklas till en insiktsterapi men kunde även verka till att försvaren förstärktes. / Today's information society, is offering new ways to interact, to establish relationships and maintain contact between people.Technology and therapy is a way to maintain a therapeutic relationship with the help of Skype as an information technology tools. The purpose of the study is to examine psychotherapist’s experiences of the therapeutic relationship in psychodynamic psychotherapy via videocommunication. Research questions focuses on the psychotherapists' use of psychodynamic theories, the description of the therapeutic relationship and how the therapeutic alliance is being built in videocommunications. The study was a qualitative research approach with a hermeneutic method. Six therapists who pursued therapy via Skype were interviewed. The results show that therapists felt that there was a distance in the relationship which could be used positively to investigate deeper into the therapy. The therapies became wordier as transferense and countertrancferences could not be identified as easily as in a physical meeting. The therapeutic alliance felt more fragile on Skype. Discussions from the study shows in order to pursue a psychodynamic psychotherapy on Skype the therapists needed to adapt the theory to the technology. The distance in the relationship was used as a means of therapy to be developed into insight therapy but could also seem to strengthen the defenses.

With the advent of mobile Internet the amount of time people spend with multimedia applications in the mobile environment is surging and demand for high quality multimedia data over the Internet in the mobile environment is growing rapidly. However the mobile environment is significantly more unfriendly than the wired environment for multimedia applications in many ways. Network resources are limited and the condition is harder to predict. Also multimedia applications are generally delay intolerant and bandwidth demanding, and with users moving, their demand could be much more dynamic and harder to anticipate. Due to such reasons many existing mobile multimedia applications show unsatisfactory performance in the mobile environment. We target three multimedia content delivery applications and optimize with limited and unpredictable network conditions typical in the mobile Internet environment. Vehicular networks have emerged from the strong desire to communicate on the move. We explore the potential of supporting high-bandwidth applications such as video streaming in vehicular networks. Challenges include limited and expensive cellular network, etc. Internet video conferencing has become popular over the past few years, but supporting high-quality large video conferences at a low cost remains a significant challenge due to stringent performance requirements, limited and heterogeneous client. We develop a simple yet effective Valiant multicast routing to select application-layer routes and adapt streaming rates according to dynamically changing network condition in a swift and lightweight way enough to be implemented on mobile devices. Bitrate adaptive video streaming is rapidly gaining popularity. However recent measurements show weaknesses in bitrate selection strategies implemented in today's streaming players especially in the mobile environment. We propose a novel rate adaptation scheme that classifies the network condition into stable and unstable periods and optimizes video quality with different strategies based on the classification. / text

Pagrindinis šio darbo tikslas buvo suprasti kas yra vaizdo konferencijos, kokios yra naudojamos technologijos interaktyviam bendravimui, išsiaiškinti kokios yra didžiausios kompanijos vaizdo konferencijų sprendimų rinkoje ir kokius produktus jie siūlo, suvokti kokie protokolai ir standartai yra naudojami vaizdo konferencijų transliavimui, pristatyti kaip skirtingos vaizdo konferencijų sistemos iš skirtingų gamintojų gali komunikuoti viena su kita. Šio vaizdo konferencijų naudojimo galimybių tyrimo pabaigoje galima rasti vaizdo konferencijų infrastruktūros rekomendacijas skirtingoms vartotojų grupėms (namų vartotojai, mokyklos, nuotolinio mokymo klasės, nuotolinio mokymo centrai), kurios buvo suskirstytos pagal savo dydį ir poreikius. Taip pat gale yra pateikiamos darbo išvados. / The main goal of this paper was to understand what is video conference, what technologies are used for interactive communications, to find out which companies are the biggest players in videoconferencing solutions market and what products they are offering, to realize what protocols and standards are used in videoconferencing, to introduce how videoconferencing systems from different vendors can communicate with each other. In the in the end of this research of opportunities of using video conferences you can find recommendations for video conference infrastructure for different users groups (home users, schools, distance learning class, distance learning center) which were distributed by their size and needs. Also you can find conclusions in the end of this research.

This thesis deals with the possibilities of video conferencing in Asterisk PBX and their use in practice. They also described the contingencies and how its configuration. Particular attention is paid to the protocols SIP, IAX and H.323, which are described in one of the chapters. The thesis was created by the Asterisk PBX, which demonstrates cooperation with videoconferencing clients. The thesis describes the configuration files so that the central set. Conclusion the work assesses the use of codecs for different clients.

Following the rapid development of mobile infrastructure and hand-held user devices like smartphones and tablets, the way that mobile networks have been utilized has changed accordingly. Users are no longer using their phones just to talk to and message each other, but have migrated most of their multimedia consumption to these devices. The increased network strain and reduced profit margins that new services bring to the table might lead to future decoupling between revenues and expenses in the network. In order to avoid this scenario various different strategies have been proposed and one of them is introduction of QoS/QoE related resource allocation techniques. This thesis looks at Interruption Prediction scheduler which tries to predict and prevent audio or video interruptions experienced during video conference call. In order to test the performance of these schedulers, MATLAB simulator reusing some of the functions from RUNE toolbox has been used. Results of the newly presented algorithms are compared with a QoE/QoS agnostic scheduler. Unfortunately results of these schedulers in the case of video conference are not as promising as they were in the case of some other types of services. The research done shows that these modifications of the scheduling algorithms do not help to increase the network performance in terms of observed KPIs (Total Time of Interruptions, Frequency of Interruptions and network throughput) in most of the described scenarios. However, there are some special scenarios when these schedulers show a certain potential.

<p>This thesis reports on the development of a Two Way Interactive Video eConsult System (TWIVES), a telemedicine application for the continuity of care in rural communities, remote areas, and in developing countries. In developed countries like Canada, there has been much development of complex telemedicine solutions that may not be suitable for rural communities in developing countries. TWIVES can be a useful alternative when mobility is limited, the patient is disabled, or commuting is not an option for the patient. This system is both easy and inexpensive to use, and operates well in the low bandwidth Internet connections available in these areas.</p> <p>TWIVES aims to facilitate an environment where users can securely request medical consultations from healthcare providers at distant locations, thereby saving time, money, and providing patients access to medical expertise that would otherwise not be available. TWIVES also introduces the concept of web-based submission of requests, replacing the existing traditional method of telephoning to arrange personal face-to-face appointments.</p> <p>TWIVES is a proof of concept (POC) designed and built with the Drupal framework, with particular attention paid to access control and user management, content management, custom search, private messaging and file sharing, request management, and real time video consultation. This thesis explain the purpose and features of TWIVES, its interfaces, what it can do, the constraints under which it must operate, and how it will react to external stimuli.</p> / Master of Science (MSc)