Scalable propagation of continuous actions in peer-to-peer-based massively multiuser virtual environments : the continuous events approach

Peer-to-Peer-based Massively Multiuser Virtual Environments (P2P-MMVEs) provide a shared virtual environment for up to several thousand simultaneous users based on a peer-to-peer network. Users interact in the virtual environment by controlling virtual representations of themselves, so-called avatars. Their computers communicate with each other via a wide area network such as the Internet to provide the shared virtual environment. A crucial challenge for P2P-MMVEs is propagating state changes of objects in the virtual environment between a large number of user computers in a scalable way. Objects may change their state on one of the computers, e.g. their position. Information about a state change has to be propagated via the peer-to-peer network to computers of other users whose avatars are able to perceive the object. Optimization algorithms for a scalable propagation of state changes are needed because of the very large number of users and the typically limited bandwidth of their Internet connections. This thesis describes an approach that optimizes the propagation of state changes caused by continuous actions. Continuous actions lead to multiple subsequent state changes over a given period of time. Instead of propagating each subsequent state change caused by continuous actions via the network, the approach propagates descriptions of the actions included in so-called continuous events. Based on the descriptions, the subsequent state changes are calculated and applied over time on each user's computer. Continuous events contain information about (1) the timing of calculations, (2) the spatial extent of the influence of the continuous action in the virtual environment over time and (3) the effect of the continuous action on influenced objects over time. The propagation and management of continuous events is performed based on the spatial publish subscribe communication model. Each user computer declares interest in a certain space in the virtual environment. If the space intersects with the spatial extent of the influence of a continuous event, the particular computer is provided with the continuous event. This thesis describes the basic concept of continuous events, presents a system architecture for support of continuous events in the context of a given target system model for P2P-MMVEs, and evaluates the continuous events approach based on a prototypical implementation of the system architecture

Secure communication using dynamic VPN provisioning in an Inter-Cloud environment

Most of the current cloud computing platforms offer Infrastructure as a Service (IaaS) model, which aims to provision basic virtualised computing resources as on-demand and dynamic services. Nevertheless, a single cloud does not have limitless resources to offer to its users, hence the notion of an Inter-Cloud enviroment where a cloud can use the infrastructure resources of other clouds. However, there is no common framework in existence that allows the srevice owners to seamlessly provision even some basic services across multiple cloud service providers, albeit not due to any inherent incompatibility or proprietary nature of the foundation technologies on which these cloud platforms are built. In this paper we present a novel solution which aims to cover a gap in a subsection of this problem domain. Our solution offer a security architecture that enables service owners to provision a dynamic and service-oriented secure virtual private network on top of multiple cloud IaaS providers. It does this by leveraging the scalability, robustness and flexibility of peer- to-peer overlay techniques to eliminate the manual configuration, key management and peer churn problems encountered in setting up the secure communication channels dynamically, between different components of a typical service that is deployed on multiple clouds. We present the implementation details of our solution as well as experimental results carried out on two commercial clouds

JXTA-Overlay: a P2P platform for distributed, collaborative, and ubiquitous computing

With the fast growth of the Internet infrastructure and the use of large-scale complex applications in industries, transport, logistics, government, health, and businesses, there is an increasing need to design and deploy multifeatured networking applications. Important features of such applications include the capability to be self-organized, be decentralized, integrate different types of resources (personal computers, laptops, and mobile and sensor devices), and provide global, transparent, and secure access to resources. Moreover, such applications should support not only traditional forms of reliable distributing computing and optimization of resources but also various forms of collaborative activities, such as business, online learning, and social networks in an intelligent and secure environment. In this paper, we present the Juxtapose (JXTA)-Overlay, which is a JXTA-based peer-to-peer (P2P) platform designed with the aim to leverage capabilities of Java, JXTA, and P2P technologies to support distributed and collaborative systems. The platform can be used not only for efficient and reliable distributed computing but also for collaborative activities and ubiquitous computing by integrating in the platform end devices. The design of a user interface as well as security issues are also tackled. We evaluate the proposed system by experimental study and show its usefulness for massive processing computations and e-learning applications.Peer ReviewedPostprint (author's final draft

Exploiting P2P in the Creation of Game Worlds

Peer-to-peer networks are a promising platform for supporting entirely decentralized, distributed multi-user gaming; however, multi-player games typically require highly predictable performance from the underlying network. This is at odds with the inherently unreliable nature of peer-to-peer environments. Existing approaches to providing peer-to-peer support for multi-player gaming focus on compensating for the unpredictability of the underlying network. We propose that rather than trying to compensate for these factors, they can be exploited together with information about the peer-to-peer network in order to address the problem of maintaining a novel gaming experience in the absence of a central authority. In order to explore our proposition, we model the measurable properties of P2P networks within a distributed multi-player game – NetWorld. We do this in such a way that the heterogeneous and unpredictable nature of the peer-to-peer environment becomes a positive part of the player’s experience

Multimedia delivery in the future internet

The term “Networked Media” implies that all kinds of media including text, image, 3D graphics, audio and video are produced, distributed, shared, managed and consumed on-line through various networks, like the Internet, Fiber, WiFi, WiMAX, GPRS, 3G and so on, in a convergent manner [1]. This white paper is the contribution of the Media Delivery Platform (MDP) cluster and aims to cover the Networked challenges of the Networked Media in the transition to the Future of the Internet. Internet has evolved and changed the way we work and live. End users of the Internet have been confronted with a bewildering range of media, services and applications and of technological innovations concerning media formats, wireless networks, terminal types and capabilities. And there is little evidence that the pace of this innovation is slowing. Today, over one billion of users access the Internet on regular basis, more than 100 million users have downloaded at least one (multi)media file and over 47 millions of them do so regularly, searching in more than 160 Exabytes1 of content. In the near future these numbers are expected to exponentially rise. It is expected that the Internet content will be increased by at least a factor of 6, rising to more than 990 Exabytes before 2012, fuelled mainly by the users themselves. Moreover, it is envisaged that in a near- to mid-term future, the Internet will provide the means to share and distribute (new) multimedia content and services with superior quality and striking flexibility, in a trusted and personalized way, improving citizens’ quality of life, working conditions, edutainment and safety. In this evolving environment, new transport protocols, new multimedia encoding schemes, cross-layer inthe network adaptation, machine-to-machine communication (including RFIDs), rich 3D content as well as community networks and the use of peer-to-peer (P2P) overlays are expected to generate new models of interaction and cooperation, and be able to support enhanced perceived quality-of-experience (PQoE) and innovative applications “on the move”, like virtual collaboration environments, personalised services/ media, virtual sport groups, on-line gaming, edutainment. In this context, the interaction with content combined with interactive/multimedia search capabilities across distributed repositories, opportunistic P2P networks and the dynamic adaptation to the characteristics of diverse mobile terminals are expected to contribute towards such a vision. Based on work that has taken place in a number of EC co-funded projects, in Framework Program 6 (FP6) and Framework Program 7 (FP7), a group of experts and technology visionaries have voluntarily contributed in this white paper aiming to describe the status, the state-of-the art, the challenges and the way ahead in the area of Content Aware media delivery platforms

Query management in a sensor environment

Traditional sensor network deployments consisted of fixed infrastructures and were relatively small in size. More and more, we see the deployment of ad-hoc sensor networks with heterogeneous devices on a larger scale, posing new challenges for device management and query processing. In this paper, we present our design and prototype implementation of XSense, an architecture supporting metadata and query services for an underlying large scale dynamic P2P sensor network. We cluster sensor devices into manageable groupings to optimise the query process and automatically locate appropriate clusters based on keyword abstraction from queries. We present experimental analysis to show the benefits of our approach and demonstrate improved query performance and scalability

The essence of P2P: A reference architecture for overlay networks

The success of the P2P idea has created a huge diversity of approaches, among which overlay networks, for example, Gnutella, Kazaa, Chord, Pastry, Tapestry, P-Grid, or DKS, have received specific attention from both developers and researchers. A wide variety of algorithms, data structures, and architectures have been proposed. The terminologies and abstractions used, however, have become quite inconsistent since the P2P paradigm has attracted people from many different communities, e.g., networking, databases, distributed systems, graph theory, complexity theory, biology, etc. In this paper we propose a reference model for overlay networks which is capable of modeling different approaches in this domain in a generic manner. It is intended to allow researchers and users to assess the properties of concrete systems, to establish a common vocabulary for scientific discussion, to facilitate the qualitative comparison of the systems, and to serve as the basis for defining a standardized API to make overlay networks interoperable

Experimental Results and Evaluation of SmartBox Stimulation Device in a P2P E-learning System

In this paper, we present the experimental results and evaluation of the SmartBox stimulation device in P2P e-learning system which is based on JXTA-Overlay. We also show the design and implementation of the SmartBox environment that is used for stimulating the learners motivation to increase the learning efficiency. The SmartBox is integrated with our P2P system as a useful tool for monitoring and controlling learners¿ activity. We found by experimental results that the SmartBox is an effective way to increase the learner¿s concentration. We also investigated the relation between learner¿s body movement, concentration, and amount of study. From the experimental results, we conclude that the use of SmartBox is an effective way to stimulate the learners in order to continue studying while maintaining the concentration.En aquest article es presenten els resultats experimentals i l'avaluació del dispositiu d'estimulació SmartBox en un sistema d'aprenentatge en línia P2P que es basa en la superposició de JXTA. També es mostra el disseny i implementació de l'ambient de l'SmartBox que s'utilitza per a estimular la motivació dels estudiants per augmentar l'eficiència en l'aprenentatge. L'SmartBox s'integra amb el nostre sistema de P2P com una eina útil per al monitoratge i per controlar l'activitat dels alumnes. Pels resultats experimentals trobem que l'SmartBox és una forma efectiva d'augmentar la concentració de l'alumne. També es va investigar la relació entre el moviment del cos de l'alumne, la concentració i la quantitat d'estudis. Dels resultats experimentals es conclou que l'ús de l'SmartBox és una manera efectiva d'estimular els estudiants per tal que continuïn els seus estudis mentre es manté la seva concentració.En este artículo se presentan los resultados experimentales y la evaluación del dispositivo de estimulación SmartBox en un sistema de aprendizaje en línea P2P que se basa en la superposición de JXTA. También se muestra el diseño e implementación del ambiente del SmartBox que se utiliza para estimular la motivación de los estudiantes para aumentar la eficiencia en el aprendizaje. El SmartBox se integra con nuestro sistema de P2P como una herramienta útil para la monitorización y para controlar la actividad de los alumnos. Por los resultados experimentales encontramos que la SmartBox es una forma efectiva de aumentar la concentración del alumno. También se investigó la relación entre el movimiento del cuerpo del alumno, la concentración y la cantidad de estudios. De los resultados experimentales se concluye que el uso del SmartBox es una manera efectiva de estimular a los estudiantes para que continúen sus estudios mientras se mantiene su concentración