Stream Dependent Caching

Author(s):  
Phillip K.C. Tse

Caching has been successfully implemented on the Internet to reduce workload on the content server and the Internet. We have seen in the last chapter how the cache replacement methods are adapted for multimedia objects in memory caching. In this chapter, we shall show how the caching is tailored to provide better performance for continuous request streams. Even though caching reduces the access latency when there are cache hits, there are chances that cache misses occur. When cache misses occur, the request stream is sent through the network to the remote storage devices. The requests are then served at the remote storage devices. The requested multimedia objects are retrieved from the storage devices, delivered through the network to the client. The cache content will also be modified to store the accessed object.

Author(s):  
Phillip K.C. Tse

Tertiary storage devices provide huge storage capacity at low cost. Multimedia objects stored on the tertiary storage devices are accessed with high latency. Despite the high access latency, some tertiary storage devices are able to deliver data at high throughput. The time slicing method is designed to reduce the start-up latency in accessing multimedia objects from tertiary storage devices. The start-up latency is lowered by reducing the amount of data being migrated in stage one of the staging method being described in the last chapter. In order to support the time-slicing method, the tertiary storage devices should have the ability to deliver data at high throughput. The tertiary storage devices that cannot deliver data at sufficiently high throughput; the start-up latency cannot be reduced.


2017 ◽  
Vol 63 (1) ◽  
pp. 77-84 ◽  
Author(s):  
Usman Anwar ◽  
Joon-Young Paik ◽  
Rize Jin ◽  
Tae-Sun Chung

Author(s):  
Philip Kwok Chung Tse

On the Internet, multimedia objects are stored in content servers. The clients behind some proxy servers are located over a wide area network (WAN) far from the content servers (Figure 1). When a client accesses multimedia objects from a content server, the content server must either allocate sufficient disk and network resources to multicast or unicast the objects to the client (Ma & Shin, 2002). Otherwise, it rejects the client. Thus, the popular content server becomes the bottleneck in delivering multimedia objects. Proxy servers have the disk cache space, network bandwidth, and availability to cache parts of the multimedia objects for clients, making them good candidates to solve the bottleneck problem. However, large multimedia objects are not cached or only partially cached in current proxy servers. When fast optical networks are widely deployed, this problem is becoming more severe. Therefore, proxy caches must be enhanced to alleviate the bottleneck in popular content servers with multimedia objects. Multimedia proxy servers perform several functions in accessing multimedia objects over the Internet. We first present the background in the next section. Next, the cache replacement policies being used in proxy servers are described. Then, the object partitioning methods are described. After that, the transcoding method that converts high-resolution objects into low-resolution objects is described. Afterward, we present the cooperative caching method that can be applied to cache objects on proxy servers. Lastly, we describe a method to distribute proxy-server load using a depot.


2021 ◽  
Vol 11 (23) ◽  
pp. 11527
Author(s):  
Eunsam Kim ◽  
Yunho Cho ◽  
Hyoseop Shin

Distributed appliances connected to the Internet have provided various multimedia services. In particular, networked Personal Video Recorders (PVRs) can store broadcast TV programs in their storage devices or receive them from central servers, enabling people to watch the programs they want at any desired time. However, the conventional CDNs capable of supporting a large number of concurrent users have limitations in scalability because more servers are required in proportion to the increased users. To address this problem, we have developed a time-shifted live streaming system over P2P networks so that PVRs can share TV programs with each other. We propose cooperative buffering schemes to provide the streaming services for time-shifted periods even when the number of PVRs playing back at the periods is not sufficient; we do so by utilizing the idle resources of the PVRs playing at the live broadcast time. To determine which chunks to be buffered, they consider the degree of deficiency and proximity and the ratio of playback requests to chunk copies. Through extensive simulations, we show that our proposed buffering schemes can significantly extend the time-shifting hours and compare the performance of two buffering schemes in terms of playback continuity and startup delay.


Author(s):  
Hakikur Rahman

Information is typically stored, manipulated, delivered, and retrieved using a plethora of existing and emerging technologies. Businesses and organizations must adopt these emerging technologies to remain competitive. However, the evolution and progress of the technology (object orientation, high-speed networking, Internet, and so on) has been so rapid, that organizations are constantly facing new challenges in end-user training programs. These new technologies are impacting the whole organization, creating a paradigm shift which, in turn, enables them to do business in ways never possible before (Chatterjee & Jin, 1997). Information systems based on hypertext can be extended to include a wide range of data types, resulting in hypermedia, providing a new approach to information access with data storage devices, such as magnetic media, video disk, and compact disk. Along with alphanumeric data, today’s computer systems can handle text, graphics, and images, thus bringing audio and video into everyday use. DETF Report (2000) refers that technology can be classified into noninteractive and time-delayed interactive systems, and interactive distance learning systems. Noninteractive and time-delayed interactive systems include printed materials, correspondence, one-way radio, and television broadcasting. Interactive distance learning systems can be termed as “live interactive” or “stored interactive,” and range from satellite and compressed videoconferencing, to standalone computer-assisted instruction with two or more participants linked together, but situated in locations that are separated by time and/or place. Different types of telecommunications technology are available for the delivery of educational programs to single and multiple sites throughout disunited areas and locations. Diaz (1999) indicated that there are numerous multimedia technologies that can facilitate self-directed, practice-centered learning and meet the challenges of educational delivery to the adult learner. Though, delivering content via the WWW has been tormented by unreliability and inconsistency of information transfer, resulting in unacceptable delays and the inability to effectively deliver complex multimedia elements, including audio, video, and graphics. A CD/Web hybrid, a Web site on a compact disc (CD), combining the strengths of the CD-ROM and the WWW, can facilitate the delivery of multimedia elements by preserving connectivity, even at constricted bandwidth. Compressing a Web site onto a CD-ROM can reduce the amount of time that students spend interacting with a given technology, and can increase the amount of time they spend learning. University teaching and learning experiences are being replicated independently of time and place via appropriate technology-mediated learning processes, like the Internet, the Web, CD-ROM, and so on. However, it is possible to increase the educational gains possible by using the Internet while continuing to optimize the integration of other learning media and resources through interactive multimedia communications. Among other conventional interactive teaching methods, Interactive Multimedia Methods (IMMs) seems to be adopted as another mainstream in the path of distance learning system.


2019 ◽  
Vol 7 (41) ◽  
pp. 23280-23300 ◽  
Author(s):  
Tao-Tse Huang ◽  
Wenzhuo Wu

The nanomaterial-based wearable energy storage devices will usher in exciting opportunities in emerging technologies such as consumer electronics, pervasive computing, human–machine interface, robotics, and the Internet of Things.


Author(s):  
Er. Mandeep Kaur

Abstract: Cloud computing is used to describe the delivery of software, infrastructure and storage devices over the internet. After evolution of the internet, Cloud computing is the next stage. Cloud Computing can simply the way in which the business operates, particularly in terms of needs of hardware. One is able to access and connect the same information but it can be done from anywhere and a more streamed technology installation is enjoyed by organization. VCloud Computing involves the concepts of parallel processing and distributed computing in order to provide the shared resources by means of Virtual Machines(VMs) hosted by physical servers. It is a service oriented design that reduces the cost of access to gather the information of the clients offer greater flexibility and demand based services. The benefits of Cloud Computing are far reaching. It is not a technology solution or server stored in another location but it is business enhanced computing that affects the business positively. Apart of its popularity it has some concerns which are becoming huddles for its wider adoption. A survey of cloud computing and virtual migration is presented in this paper. Keywords: Cloud Computing, Virtualization, SaaS, PaaS, IaaS


Author(s):  
Parkavi Ravi ◽  
Priyanka Chinnaiah ◽  
Sheik Adullah Abbas

Green computing, also called green equipment, is the environmentally sustainable to use of computers and related resources like - monitors, printer, storage devices, networking and communication systems - effectively with minimal or no impact on the environment. Green cloud is a catchphrase that refers to the potential environmental benefits that information technology (IT) services delivered over the Internet will present society. The word combines the words green meaning environmentally gracious and cloud, the traditional image for online and the shortened name for a type of service delivery model known as cloud processing.


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