Scheduling and buffering mechanisms for remote rendering streaming in virtual walkthrough class of applications

Abstract

With the recent advances of wireless networking and mobile devices technologies, exploration of remote 3D virtual environments has received a great deal of attention nowadays where many applications can be envisioned, such as virtual guides malls, online gaming, just to name a few. The primary objective of this paper is to present the specification of a buffering mechanism and a scheduling solution for ontime image delivery for a class of applications that is based upon a remote virtual environment exploration. Similar to a video buffering, our approach involves buffering the images closest to the user's position within the virtual environment, thereby, providing the client device with the necessary imagery data for rendering future user's viewpoints, removing network jitter, and providing smooth virtual interaction. In this paper, in order to overcome the limitations of current mobile device graphics performance, we propose to use a remote rendering approach that streams the necessary images to a client device as the user explores the virtual environment, leaving only the display and a number of minor image-based rendering tasks to the local, less powerful mobile hardware. Using ns-2, we present and extensive set of simulation experiments to evaluate the performance of our scheme. Our results indicate clearly that our solution is able to guarantee on-time delivery for approximately 40 sessions with a 10 Mbps link.

Prediction-based Prefetching for Remote Rendering Streaming in Mobile Virtual Environments

“…When the user stops, the client sends a request to the server, which will then send a high resolution image of the scene. Furthermore, [1] used panoramic image-based rendering, which consists of creating a panorama representation of the scene from several images taken by rotating the camera around a fixed point. Figure 1 shows the client server architecture introduced in [1] for rendering and streaming over the wireless network.…”

“…Furthermore, [1] used panoramic image-based rendering, which consists of creating a panorama representation of the scene from several images taken by rotating the camera around a fixed point. Figure 1 shows the client server architecture introduced in [1] for rendering and streaming over the wireless network. In addition, they introduced a prefetching scheme that streams n look-ahead images to the client.…”

“…In our proposal, the client-server architecture introduced in [1] is used. The localization technique favors the spatial locality and sends the five images covering the field of view surrounding the client as shown in Figure 3 .…”

“…In [1], Boukerche et al proposed a scheduling and buffering technique for remote rendering of virtual walkthrough applications. The client sends periodic updates with its position in the virtual scene to the server, and the server performs a look-ahead strategy to compute images that most likely required by the client in the next movements.…”

“…Moreover, they proposed a rate control scheme that adapts the sender's transmission rate to the observed received rate, and reduces the rate at congestions. Nevertheless, their system in [1] suffered from the following drawbacks:…”