16,971 research outputs found

    Selection strategies for peer-to-peer 3D streaming

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    In multi-user networked virtual environments such as Sec-ond Life, 3D streaming techniques have been used to pro-gressively download and render 3D objects and terrain, so that a full download or prior installation is not necessary. As existing client-server architectures may not scale easily, 3D streaming based on peer-to-peer (P2P) delivery is recently proposed to allow users to acquire 3D content from other users instead of the server. However, discovering the peers who possess relevant data and have enough bandwidth to answer data requests is non-trivial. A naive query-response approach thus may be inefficient and could incur unnec-essary latency and message overhead. In this paper, we propose a peer selection strategy for P2P-based 3D stream-ing, where peers exchange information on content availabil-ity incrementally with neighbors. Requestors can thus dis-cover suppliers quickly and avoid time-consuming queries. A multi-level area of interest (AOI) request is also adopted to avoid request contention due to concentrated requests. Simulation results show that our strategies achieve better system scalability and streaming performance than a naive query-response approach

    PEER-TO-PEER 3D/MULTI-VIEW VIDEO STREAMING

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    Abstract The recent advances in stereoscopic video capture, compression and display have made 3D video a visually appealing and costly affordable technology. More sophisticated multi-view videos have also been demonstrated. Yet their remarkably increased data volume poses greater challenges to the conventional client/server systems. The stringent synchronization demands from different views further complicate the system design. In this thesis, we present an initial attempt toward efficient streaming of 3D videos over peer-to-peer networks. We show that the inherent multi-stream nature of 3D video makes playback synchronization more difficult. We address this by a 2-stream buffer, together with a novel segment scheduling. We further extend our system to support multi-view video with view diversity and dynamics. We have evaluated our system under different end-system and network configurations with typical stereo video streams. The simulation results demonstrate the superiority of our system in terms of scalability, streaming quality and dealing with view dynamics

    A case for 3D streaming on peer-to-peer networks

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    One of the most serious issues holding back the widespread of 3D contents on Internet has been their inaccessibility due to large data volume. Many compression and progressive transmission tech-niques, as well as format standards, have been proposed in recent years to make 3D streaming increasingly viable for the efficient and accessible delivery of 3D contents. However, existing propos-als have yet to seriously address one of the most important issues in practical adoption – a system’s scalability in terms of the number of concurrent users. We argue that due to 3D contents ’ large data vol-ume and interactive nature, client-server architecture, with its inher-ently fixed resource availability and high cost, will not be suitable to support popular Internet-scale 3D streaming. On the other hand, peer-to-peer (P2P) architectures hold the promise of both scalabil-ity and affordability. In this position paper, we describe the po-tential promises and challenges in adapting 3D streaming to P2P networks, using multi-user networked virtual environment (NVE) as an example. We also propose Flowing LoD (FLoD), a scalable, distributed and fault-tolerant P2P 3D streaming mechanism, that is based on Voronoi-based Overlay Network (VON), a P2P overlay specifically designed for NVE applications

    3D Multi-Beam and Null Synthesis by Phase-Only Control for 5G Antenna Arrays

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    This paper presents an iterative algorithm for the synthesis of the three-dimensional (3D) radiation pattern generated by an antenna array of arbitrary geometry. The algorithm is conceived to operate in fifth-generation (5G) millimeter-wave scenarios, thus enabling the support of multi-user mobile streaming and massive peer-to-peer communications, which require the possibility to synthesize 3D patterns with wide null regions and multiple main beams. Moreover, the proposed solution adopts a phase-only control approach to reduce the complexity of the feeding network and is characterized by a low computational cost, thanks to the closed-form expressions derived to estimate the phase of each element at the generic iteration. These expressions are obtained from the minimization of a weighted cost function that includes all the necessary constraints. To finally check its versatility in a 5G environment, the developed method is validated by numerical examples involving planar and conformal arrays, considering desired patterns with different numbers of main beams and nulls

    3D video coding and transmission

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    The capture, transmission, and display of 3D content has gained a lot of attention in the last few years. 3D multimedia content is no longer con fined to cinema theatres but is being transmitted using stereoscopic video over satellite, shared on Blu-RayTMdisks, or sent over Internet technologies. Stereoscopic displays are needed at the receiving end and the viewer needs to wear special glasses to present the two versions of the video to the human vision system that then generates the 3D illusion. To be more e ffective and improve the immersive experience, more views are acquired from a larger number of cameras and presented on di fferent displays, such as autostereoscopic and light field displays. These multiple views, combined with depth data, also allow enhanced user experiences and new forms of interaction with the 3D content from virtual viewpoints. This type of audiovisual information is represented by a huge amount of data that needs to be compressed and transmitted over bandwidth-limited channels. Part of the COST Action IC1105 \3D Content Creation, Coding and Transmission over Future Media Networks" (3DConTourNet) focuses on this research challenge.peer-reviewe

    An Efficient Transport Protocol for delivery of Multimedia An Efficient Transport Protocol for delivery of Multimedia Content in Wireless Grids

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    A grid computing system is designed for solving complicated scientific and commercial problems effectively,whereas mobile computing is a traditional distributed system having computing capability with mobility and adopting wireless communications. Media and Entertainment fields can take advantage from both paradigms by applying its usage in gaming applications and multimedia data management. Multimedia data has to be stored and retrieved in an efficient and effective manner to put it in use. In this paper, we proposed an application layer protocol for delivery of multimedia data in wireless girds i.e. multimedia grid protocol (MMGP). To make streaming efficient a new video compression algorithm called dWave is designed and embedded in the proposed protocol. This protocol will provide faster, reliable access and render an imperceptible QoS in delivering multimedia in wireless grid environment and tackles the challenging issues such as i) intermittent connectivity, ii) device heterogeneity, iii) weak security and iv) device mobility.Comment: 20 pages, 15 figures, Peer Reviewed Journa

    Enabling collaboration in virtual reality navigators

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    In this paper we characterize a feature superset for Collaborative Virtual Reality Environments (CVRE), and derive a component framework to transform stand-alone VR navigators into full-fledged multithreaded collaborative environments. The contributions of our approach rely on a cost-effective and extensible technique for loading software components into separate POSIX threads for rendering, user interaction and network communications, and adding a top layer for managing session collaboration. The framework recasts a VR navigator under a distributed peer-to-peer topology for scene and object sharing, using callback hooks for broadcasting remote events and multicamera perspective sharing with avatar interaction. We validate the framework by applying it to our own ALICE VR Navigator. Experimental results show that our approach has good performance in the collaborative inspection of complex models.Postprint (published version
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