Networking Middleware and Online-Deployment Mechanisms for Java-Based Games

Currently, web-based online gaming applications are predominately utilising Adobe Flash or Java Applets as their core technologies. These games are often casual, two-dimensional games and do not utilise the specialist graphics hardware which has proliferated across modern PCs and Consoles. Multi-user online game play in these titles is often either non-existent or extremely limited. Computer games applications which grace the current generation of consoles and personal computers are designed to utilise the increasingly impressive hardware power at their disposal. However, these are commonly distributed using a physical medium or deployed through custom, proprietary networking mechanisms and rely upon platform-specific networking APIs to facilitate multi-user online game play. In order to unify the concepts of these disparate styles of gaming, this paper presents two interconnected systems which are implemented using Java Web Start and JXTA P2P technologies, providing a platform-independent framework capable of deploying hardware accelerated cross-platform, cross-browser online-enabled Java games, as part of the Homura Project

Inter-Destination Multimedia Synchronization; Schemes, Use Cases and Standardization

Traditionally, the media consumption model has been a passive and isolated activity. However, the advent of media streaming technologies, interactive social applications, and synchronous communications, as well as the convergence between these three developments, point to an evolution towards dynamic shared media experiences. In this new model, geographically distributed groups of consumers, independently of their location and the nature of their end-devices, can be immersed in a common virtual networked environment in which they can share multimedia services, interact and collaborate in real-time within the context of simultaneous media content consumption. In most of these multimedia services and applications, apart from the well-known intra and inter-stream synchronization techniques that are important inside the consumers playout devices, also the synchronization of the playout processes between several distributed receivers, known as multipoint, group or Inter-destination multimedia synchronization (IDMS), becomes essential. Due to the increasing popularity of social networking, this type of multimedia synchronization has gained in popularity in recent years. Although Social TV is perhaps the most prominent use case in which IDMS is useful, in this paper we present up to 19 use cases for IDMS, each one having its own synchronization requirements. Different approaches used in the (recent) past by researchers to achieve IDMS are described and compared. As further proof of the significance of IDMS nowadays, relevant organizations (such as ETSI TISPAN and IETF AVTCORE Group) efforts on IDMS standardization (in which authors have been and are participating actively), defining architectures and protocols, are summarized.This work has been financed, partially, by Universitat Politecnica de Valencia (UPV), under its R&D Support Program in PAID-05-11-002-331 Project and in PAID-01-10, and by TNO, under its Future Internet Use Research & Innovation Program. The authors also want to thank Kevin Gross for providing some of the use cases included in Sect. 1.2.Montagud, M.; Boronat Segui, F.; Stokking, H.; Van Brandenburg, R. (2012). Inter-Destination Multimedia Synchronization; Schemes, Use Cases and Standardization. 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Network traffic analysis and evaluation of a multi-user virtual environment

Virtual world applications allow users to interact within a simulated world. Network responsiveness and reliability contribute to the user experience, thus being able to model and reproduce certain network scenarios is a key issue to assure proper user experience and for being able to provide an estimation of the required network resources. The present study aims to model the client network traffic for the virtual world application Open Wonderland as the basis to tools for evaluating its network requirements. A micro scale modelling was performed, studying the outgoing network traffic from a black box approach that omits the details of traffic generation of the subcomponents and focuses on their overall combined traffic. The model obtained provides high goodness of fit for audio and object synchronisation traffic, reflected in a Pearson correlation coefficient close to its maximum value and low deviation figures measured by Root Mean Square Deviation.Ministerio de Ciencia e innovación IPT-2011-1038-900000Ministerio de Ciencia e innovación TEC2009-10639-C04-0

Distributed game

Dissertação de mestrado em Engenharia InformáticaThe demand for online games has risen over the years, expanding multiplayer support for new and different game genres. Among them are Massively Multiplayer Online games, one of the most popular and successful game types in the industry. Nowadays, this industry is thriving, evolving alongside technological advancements and producing billions in revenue, making it an economic importance. However, as the complexity of these games grows, so do the challenges they face when constructing them. This dissertation aims to implement a distributed game, through a proof of concept or an existing game, using a distributed architecture to acquire knowledge in the construction of such complex systems and the effort involved in dealing with consistency, maintaining communication infrastructure, and managing data in a distributed way. It is also intended that this project implements multiple mechanisms capable of autonomously helping manage and maintain the correct state of the system. To evaluate the proposed solution, a detailed analysis is carried out with performance benchmark analysis, stress testing, followed by an examination of its security, scalability, and distribution’s resilience. Overall, the present research work allowed for a greater understanding of the technologies and approaches used in constructing a gaming system, establishing a new set of development opportunities to be further investi gated upon the constructed solution.A procura por jogos online aumentou ao longo dos anos, expandindo o suporte multiplayer para novos e diferentes géneros. Entre estes estão os jogos Massively Multiplayer Online, um dos tipos de jogos mais populares e bem-sucedidos na indústria. Atualmente, esta indústria está a prosperar, evoluindo com os avanços tecnológicos e gerando milhares de milhões em receita, tornando-se uma importância económica. Porém, à medida que a complexidade destes jogos aumenta, também aumenta os problemas encontrados durante a sua construção. Esta dissertação tem como objetivo implementar um jogo distribuído, através de uma prova de conceito ou um jogo existente, usando uma arquitetura distribuída a fim de adquirir conhecimento na construção destes sistemas complexos e o esforço envolvido em lidar com consistência, manter a infraestrutura de comunicação e gerir dados de maneira distribuída. Para isto, é pretendido que este projeto também implemente vários mecanismos capazes de, forma autônoma, ajudar a gerir e manter o correto estado do sistema. Para avaliar o solução proposta, uma análise detalhada é realizada sobre o desempenho, segurança, escalabilidade e resiliência da distribuição do sistema. De forma geral, o presente trabalho de pesquisa permitiu uma maior compreensão das tecnologias e abordagens utilizadas na construção de um sistema de jogos, estabelecendo um novo conjunto de oportunidades de desenvolvimento a serem investigadas sobre a solução construída

Agent based infrastructure for real-time applications

In this paper we propose a new infrastructure for real-time applications. As a preliminary, we describe basic characteristics of the most popular real-time services like VoIP, videoconferencing, live media streaming, and network multiplayer games. We focus on the end-to-end latency, bandwidth and efficient transmission methods. Next, we present our project concepts, infrastructure model, details of implementation and our testing environment which was designed for testing many aspects of real-time services. The system combines mechanisms for ensuring best possible connection quality (QoS), load balance of servers in infrastructure and gives control over the packet routing decisions. Additionally, provided security mechanisms make it a good choice even in the environment where a high security level is required. The system is based on the Peer-to-Peer (P2P) model and data between users is routed over an overlay network, consisting of all participating peers as network nodes. This overlay can by used for application level multicast or live media stream. In the logging process each user is assigned to a specific node (based on his geographic location and nodes load). Because nodes are participating in data transmission, we have control over the data flow route. It is possible to specify the desired route, so, regardless of the external routing protocol, we can avoid paths that are susceptible to eavesdropping. Another feature of the presented system is usage of agents. Each agent acts within the single node. Its main task is to constantly control the quality of transmission. It analyzes such parameters like link bandwidth use, number of lost packets, time interval between each packet etc. The information collected by the agents from all nodes allows to build a dynamic routing table. Every node uses the Dijkstra's algorithm to find the best at the moment route to all other nodes. The routes are constantly modified as a consequence of changes found by agents or updates sent by other nodes. In VoD services agents also analyze popularity of streamed media, which helps build intelligent video cache. To ensure greater security and high reliability of the system, we have provided a reputation mechanism. It is used during bringing up to date the information about possible routes and their quality, given by other nodes. Owing to this solution nodes and routes which are more reliable get higher priority

Distributed virtual environment scalability and security

Distributed virtual environments (DVEs) have been an active area of research and engineering for more than 20 years. The most widely deployed DVEs are network games such as Quake, Halo, and World of Warcraft (WoW), with millions of users and billions of dollars in annual revenue. Deployed DVEs remain expensive centralized implementations despite significant research outlining ways to distribute DVE workloads. This dissertation shows previous DVE research evaluations are inconsistent with deployed DVE needs. Assumptions about avatar movement and proximity - fundamental scale factors - do not match WoW’s workload, and likely the workload of other deployed DVEs. Alternate workload models are explored and preliminary conclusions presented. Using realistic workloads it is shown that a fully decentralized DVE cannot be deployed to today’s consumers, regardless of its overhead. Residential broadband speeds are improving, and this limitation will eventually disappear. When it does, appropriate security mechanisms will be a fundamental requirement for technology adoption. A trusted auditing system (“Carbon”) is presented which has good security, scalability, and resource characteristics for decentralized DVEs. When performing exhaustive auditing, Carbon adds 27% network overhead to a decentralized DVE with a WoW-like workload. This resource consumption can be reduced significantly, depending upon the DVE’s risk tolerance. Finally, the Pairwise Random Protocol (PRP) is described. PRP enables adversaries to fairly resolve probabilistic activities, an ability missing from most decentralized DVE security proposals. Thus, this dissertations contribution is to address two of the obstacles for deploying research on decentralized DVE architectures. First, lack of evidence that research results apply to existing DVEs. Second, the lack of security systems combining appropriate security guarantees with acceptable overhead

Scalable software architecture for distributed MMORPG traffic generation based on integration of UrBBaN-Gen and IMUNES

We present a scalable software architecture for distributed traffic generation capable of producing Massively Multiplayer Online Role-Playing Game (MMORPG) packet flows in a statistically accurate manner for thousands of concurrent players. The main challenge, to achieve truly massive scale traffic generation, has been achieved by introducing kernel based virtualization, pioneered by the network simulator/emulator IMUNES, into the User Behaviour Based Network Traffic Generation (UrBBan-Gen, introduced in our earlier work). The UrBBan-Gen software architecture consists of four modules: Service repository, Control function and user interface, Behaviour process, and Traffic generation process. IMUNES has been integratedinto the virtualization part of the Traffic generation process,which has resulted in two improvements: 1) increasing thenumber of generated packet flows while accurately replicating the required statistical properties, and, 2) introducing the ability to run various network scenarios in simulated, as well as real networks, under realistic traffic loads. With respect to the traffic generation capabilities of the previous version of UrBBan-Gen, which was based on Linux containers, the IMUNES based solution demonstrates higher scalability, lower packet loss rates, and lower CPU load for both the UDP traffic at high packet rate and “thin” TCP traffic flows typical for MMORPGs

Virtual Reality Games for Motor Rehabilitation

This paper presents a fuzzy logic based method to track user satisfaction without the need for devices to monitor users physiological conditions. User satisfaction is the key to any product’s acceptance; computer applications and video games provide a unique opportunity to provide a tailored environment for each user to better suit their needs. We have implemented a non-adaptive fuzzy logic model of emotion, based on the emotional component of the Fuzzy Logic Adaptive Model of Emotion (FLAME) proposed by El-Nasr, to estimate player emotion in UnrealTournament 2004. In this paper we describe the implementation of this system and present the results of one of several play tests. Our research contradicts the current literature that suggests physiological measurements are needed. We show that it is possible to use a software only method to estimate user emotion