Tutkielma ryhmitellyistä konferensseista ja Binary Floor Control Protocol:n toteutuksesta keskitettyyn konferenssijärjestelmään

The introduction of the third generation (3G) in the mobile telecommunication world offers the possibility for a wide range of new applications and services that operators can offer to their customers. One of these services is multimedia conferencing. There is ongoing work to provide conferencing services in the IP Multimedia Subsystem (IMS) environment as one of the most significant services. This thesis focuses on providing a comprehensive overview of conferencing systems, especially of the Binary Floor Control Protocol (BFCP) and cascade conferences. The Master's Thesis consisted of two parts: The first part is a theoretical part, which provides the concepts of the centralized conferencing, known as tightly coupled conferences, and reviews the current specifications stage of the different standardization bodies. In contrast, the study of the applicability of the current centralized conferencing specifications in a cascaded conferencing environment is presented, as well as the strengths and weaknesses of them. The second part is a practical implementation of the Binary Floor Control Protocol (BFCP). BFCP is implemented in MiniSip, an existing secure open-source SIP User Agent (UA), and in Asterisk, an open source Private Branch Exchange (PBX) replacement system. BFCP is built using the specification defined by the XCON working group within the Internet Engineering Task Force (IETF). Finally, BFCP is evaluated and based on this evaluation, some conclusions are given.Kolmannen sukupolven matkapuhelinverkot mahdollistavat laajan uusien ohjelmien ja palveluiden kirjon, joita operaattorit voivat tarjota asiakkailleen. Eräs tämänlainen palvelu on multimedia konferenssi. Tällä hetkellä tehdään työtä, jonka tarkoituksena on mahdollistaa konferenssinpalvelun tarjoaminen IP Multimedia Subsystem (IMS) ympäristössä. Tämä diplomityö keskittyy konferenssijärjestelmän perusteelliseen kuvaukseen, painottuen Binary Floor Control Protocol:aan (BFCP) sekä ryhmiteltyihin konferensseihin. Työ koostuu kahdesta osasta: Ensimmäinen osa keskittyy teoriaan, joka käsittelee keskitettyjä konferenssijärjestelmiä sekä aiheen nykyistä tilaa eri standardointiorganisaatioissa. Vastakohtana tarkastellaan nykyisen keskitetyn konferenssijärjestelmän heikkouksia ja vahvuuksia. Toinen osa käsittelee käytännön toteutusta BFCP:sta, joka on toteutettu MiniSip- sekä Asterisk-ohjelmistoihin. MiniSip on avoimeen lähdekoodiin perustuva SIP käyttäjäagentti, ja Asterisk paikallisvaihdeohjelmiston (PBX) avoin korvaaja. BFCP perustuu spesifikaatioon, jonka on määritellyt XCON työryhmä IETF:ssa. Lopuksi BFCP protokollaa on arvioitu tämän toteutuksen avulla

Centralized Conferencing in the IP Multimedia Subsystem: from theory to practice

In this paper we present a conferencing architecture compliant with the IP Multimedia Subsystem (IMS) specification. To the purpose, we embrace a practical approach, by describing an actual implementation of an open source centralized video-conferencing system, called CONFIANCE, capable to offer advanced communication experience to end-users through the effective exploitation of mechanisms like session management and floor control. CONFIANCE has been designed to be fully compliant with the latest standard proposals coming from both the IETF and the 3GPP and can be considered as an outstandingexample of a real-time application built on top of the grounds paved by the SIP protocol. We will discuss in the paper both the design of the overall conferencing framework and the most important issues we had to face during the implementation phase

A Floor Control Server in a Distributed Conference Service

The conferencing systems in IP Multimedia (IM) networks are going through restructuring, accomplished in the near future. One of the changes introduced is the concept of floors and floor control in its current form with matching entity roles. The Binary Floor Control Protocol (BFCP) is a novelty to be exploited in distributed tightly coupled conferencing services. The protocol defines the floor control server (FCS), which implements floor control giving access to shared resources. As the newest tendency is to distribute the conferencing services, the locations of different functionality units play an important role in developing the standards. The floor control server location is not yet single-mindedly fixed in different standardization bodies, and the debate goes on where to place it within the media server, providing the conferencing service. The thesis main objective is to evaluate two distinctive alternatives in respect the Mp interface protocol between the respective nodes, as the interface in relation to floor control is under standardization work at the moment. The thesis gives a straightforward preamble in IMS network, nodes of interest including floor control server and conferencing. Knowledge on several protocols – BFCP, SDP, SIP and H.248 provides an important background for understanding the functionality changes introduced in the Mp interface and therefore introductions on those protocols and how they are connected to the full picture is given. The actual analysis on the impact of the floor control server into the Mp reference point is concluded in relation to the locations, giving basic flows, requirements analysis including a limited implementation proposal on supporting protocol parameters. The overall conclusion of the thesis is that even if both choices are seemingly useful, not one of the locations is clearly the most suitable in the light of this work. The thesis suggests a solution having both possibilities available to be chosen from in separate circumstances, realized with consistent standardization. It is evident, that if the preliminary assumption for the analysis is kept regarding to only one right place for the floor control server, more work is to be done in connected areas to discover the one most appropriate location

A SOAP Web Services-Based Architecture for Floor Control in Multimedia Conferencing

Multimedia conferencing applications are an important and widely-used category of Web applications. Floor control is a significant and advanced feature of multimedia conferencing applications. Floor control mechanisms, when introduced in audio/video conferencing, control the media streams such as identifying which participant is allowed to send and who can be seen or heard. This prevents conflict and ensures an optimized use of resources between the conference participants. Floor control is composed of three logical entities: a single floor control server (i.e. entity responsible for managing the floors and their status), one or more floor chairs (moderators), and any number of regular conference participants. This thesis proposes a SOAP Web services based architecture for floor control in multimedia conferencing. Web services are designed to support interoperable machine-to-machine interaction over a network. They are attractive because of their flexibility. There are two types of web services: SOAP Web services and RESTful Web services. In SOAP Web services, interactions between the entities are based on XML and use SOAP, which is embedded in HTTP. RESTful web services are an architectural design style that rely on HTTP, but do not use SOAP. XML is also optional. We propose a set of floor control requirements and use them to review the related work and pinpoint the weaknesses. The proposed architecture includes the main components of floor control. It also includes a comprehensive set of server-side and client-side SOAP web service APIs that expose the floor control capabilities to application developers. The proposed APIs are programming language-independent and provide a higher level of abstraction to the application developers, which enables the interoperability. Furthermore, in the proposed architecture the floor control clients do not interact directly with the floor control server (FCS) but through a gateway accessible using SOAP web services. This opens up the possibility to use different floor control protocols transparently to the floor control clients. Application portability is no longer a problem because floor clients access the floor capabilities independently of the protocol supported by the FCS. We have built a conferencing application with floor control as a proof of concept to demonstrate the new interface for floor control and the feasibility of the proposed architecture. In addition, performance measurements have also been made to evaluate the viability of the architecture

Technologies of data transmission in video conferencing systems

The methods and technologies, associated with video and audio data transmission in video conferencing systems were discovered. Existing problems in the field of data transmission in conferencing systems via the Internet and methods for their solution were considered. The most widely used technologies of data transmission in the video conferencing systems via the Internet were analyzed. The concept of telepresence and features of video conferencing systems that it provides were considered. Conclusions about the appropriateness of using different technologies of video and audio data transfer depending on the type of video conferencing system were made.Досліджено методи і технології передачі відео- та аудіоданих у системах відеоконференцзв’язку. Розглянуто існуючі проблеми у сфері передачі даних у системах конференцзв'язку через Інтернет і методи їх вирішення. Проаналізовано найбільш поширені технології передачі відео- та аудіоданих у системах відеоконференцзв'язку через Інтернет. Розглянуті поняття телеприсутності і особливості систем відеоконференцзв'язку, що її забезпечують. Зроблено висновки про доцільність використання різних технологій передачі відео- та аудіоданих залежно від типу системи відеоконференцзв'язку.Исследованы методы и технологии передачи видео- и аудиоданных в системах видеоконференцсвязи. Рассмотрены существующие проблемы в сфере передачи данных в системах конференцсвязи через Интернет и методы их решения. Проанализированы наиболее распространенные технологии передачи видео- и аудиоданных в системах видеоконференцсвязи через Интернет. Рассмотрены понятие телеприсутствия и особенности систем видеоконференцсвязи, которые его обеспечивают. Сделаны выводы о целесообразности использования различных технологий передачи видео- и аудиоданных в зависимости от типа системы видеоконференцсвязи

A service-enabling framework for the session initiation protocol (SIP)

In this dissertation, we propose a framework to provide multimedia communication services. Our proposed framework is based on SIP (Session Initiation Protocol) and has four fundamental properties: it is available, secure, high performing, and oriented to innovations. The framework is not an architecture with a rigid structure. Instead, the framework is a toolkit made up of a set of tools that can be combined in different ways. The combination of these tools provides applications and services with functionality needed to implement a wide variety of multimedia communication services. Applications and services built on top of the framework use different tools within the toolkit in order to provide their desired overall functionality. The functionality provided by the framework includes a number of primitives to be used by applications and services. These primitives mostly relate to multiparty communications and include floor control. The framework also offers support functions that relate to PSTN (Public Switched Telephony Network) interworking, policy control, and consent-based communications. Additionally, the framework contains functions that relate to signalling transport, multihoming, mobility, security, and NAT (Network Address Translation) traversal. The framework also allows building overlay networks when a SIP network infrastructure is not available. In order to test and refine the ideas presented in this dissertation, we have implemented most of them in proof-of-concept prototypes. We have used experiments and simulations to validate our assumptions and obtain new insights

Conference Control Design for a SIP-Web-Service Hybrid Multimedia Conference Framework

Abstract: Session Initiation Protocol (SIP) and Web service are the de facto standards for Voice over IP applications and distributed system, respectively. Although they do not be used to define multimedia conferencing directly and completely, many proposals, drafts and papers suggest extensions and solutions to this essential service. However, as the spring up of the Web service standards and technology, some traditional communication systems should be restructured and modified, including the multimedia conference framework based on SIP and Web service. In this study, a hybrid multimedia conference framework is first propose, which consist of low latency services, primitive and composite conference services. Under this framework, a multimedia conference can be organized and controlled conveniently with the property of loosely coupling and extensibility. Then the primary components of a conference control are introduced followed by the detailed design exemplified by some typical scenarios, which is compared to other possible design approaches. Finally, a specification of orchestration implementation which realizes the synthesis of the conference control functions is introduced to illustrate the feasibility of this design

E-pSylon: una herramienta para la teleenseñanza síncrona

Muchas de las herramientas de teleenseñanza actuales corresponden al modelo asíncrono, donde instructor y alumnos interactúan desde espacios y tiempos diferentes. El modelo de teleenseñanza síncrona permite incorporar estrategias probadas con éxito en la enseñanza presencial, donde el apoyo visual del instructor a las explicaciones facilita la comprensión por parte de los alumnos. Se consigue así una enseñanza guiada y una realimentación inmediata de los alumnos. En este trabajo se propone una herramienta de teleenseñanza síncrona de sencillo manejo que permite el desarrollo de clases virtuales donde instructor y alumnos interactúan en tiempo real. También se presenta la experiencia con el uso de la herramienta en asignaturas relacionadas con la Ingeniería Informática y algunas conclusiones al respecto.Peer Reviewe