Delay-Aware Scale-Free Display System under Ubiquitous Grid Networking (uGrid) Environment Yusukei Okazaki * , Yuki Susa * , Ryota Usui * , Yutaka Arakawa * , Satoru Okamoto * ,and Naoaki Yamanaka * * Department of Information and Computer Science, Faculty of Science and Technology, Keio University, 3–14–1 Hiyoshi, Kohoku-ku, Yokohama, 223–8522, Japan Email: okazaki@yamanaka.ics.keio.ac.jp Abstract—New scalable display system in a ubiquitous Grid networking (uGrid) called scale-free display system is proposed. Tiled display system which can visualize large high-resolution images has been becoming famous. However, the more display size grow large, the more hard to establish the system. Also, a study of widely distributed computing or uGrid has been growing. In this paper, we propose scale-free display system under distributed computing network and optical broad band network. In proposed system, computing resources are widely distributed in the network, so distances from each computing resource to the tiled display are different. Thus, to synchronize all frames of image, computing resources which have almost same delay to the tiled display have to be selected in case that the system starts. For this reason, we consider the method to select the computing resources. Also we examine the characteristic of delay in power-law network under the assumption that the proposed system will be applied to power-law network. I. I NTRODUCTION Fundamental TV system has not been changed for a long time. TV station broadcast contents to TV users. The users choose the program which broadcasted by TV station. Thus, due to limitation of TV program, the users might not be able to watch the program which the users really want to watch. Moreover, even if a user watches the sports program that he wants to see, the user cannot watch by the camera angle that he really wants to see. With the growth of computer system and measurement technology, the date size became large and complex. Also, necessity of the technology to visualize a data such as satellite image or electron microscope image on a large screen has risen. A study of grid computing [1] or widely distributed com- puting has been growing. Grid Computing can realize a high performance virtual machine by combining high performance computers. Likewise, with the advance of ubiquitous society, it is expected that everything will be connected to the net- work. From such a background, a ubiquitous grid networking environment (uGrid) [2], [3], [4] has been proposed. In this environment, everything is defined as “ service-parts ” and some Service-parts will be combined to provide new service for users. In this paper, new scale-free display system under uGrid environment and optical broad band network is proposed. In proposed system, computing resources are widely distributed in the network, so distances from each computing resource to the tiled display are different. Thus, to synchronize all frames of image, computing resources which have almost same delay to the tiled display have to be selected in case that the system starts. For this reason, we consider the method to select the computing resources. Also we examine the characteristic of delay in power-law network under the assumption that the proposed system will be applied to power-law network [5]. II. RELATED WORKS A. Tiled Displays Tiled display is a method to visualize a high resolution image on large scale screen composed by multiple LCD panels. Technologies to realize tiled display system, for ex- ample, SAGE (Scalable Adaptive Graphical Environment) [6], Chromium [7] and Tenmado [8] were established. In this paper, to realize the proposed system, we use and improve SAGE to apply the proposed system. B. SAGE SAGE is one of the projects developed by Electronic Visual- ization Laboratory (EVL). SAGE realizes the seamless display which can visualize simultaneously various applications such as 3D rendering, remote desktop, video streams and so on. Figure 1 shows Architecture of SAGE. SAGE composed by tiled display, a control PC, application servers, display nodes, and user interface. 1) tiled display: Tiled display composed by multiple LCPs. Each LCD connects to the display node, and LCD displays video signal from display node. 2) Control PC: Control PC manages whole of the system. Each components of SAGE is operated as control PC indicates. 3) Aplication server: Application server is a component to execute applications such as movie player, 3D rendering. Application is applied to SAGE, and output of application is captured as pixel information. Then, pixel information sends to display by streaming. 4) Display node: Each display node receives pixel informa- tion from Application server. Pixel information is converted as video signal, and is send to corresponding LCD. 5) User interface: SAGE has GUI user interface. User can execute applications, resize application windows, change the position of application windows.