Gaming@Edge:基于边缘节点的低延迟云游戏系统

云游戏作为云计算的"杀手级"应用正在引领游戏运行方式的变革。然而，云端与终端设备之间较大的网络延迟影响了云游戏的用户体验，因此，提出一种基于边缘计算理念，部署在边缘节点之上的低延迟的云游戏框架--Gaming@Edge。为了降低边缘节点的计算负载以提升其并发能力，Gaming@Edge实现了一种基于压缩图形流的云游戏运行机制--GSGOD。GSGOD分离了游戏运行中的逻辑计算和画面渲染，实现了一种边+端的计算融合。此外，GSGOD还通过数据缓存、指令流水处理以及对象状态延迟更新等机制优化了云游戏的网络数据传输和系统延迟。实验结果表明，Gaming@Edge相比传统的云游戏系统能够降低平均74%的网络延迟，并提高4.3倍游戏实例并发能力。     

Dissecting the protocol and network traffic of the OnLive cloud gaming platform

Cloud gaming is a new paradigm that is envisaged to play a pivotal role in the video game industry in forthcoming years. Cloud gaming, or gaming on demand, is a type of online gaming that allows on-demand streaming of game content onto non-specialised devices (e.g. PC, smart TV, etc.). This approach requires no downloads or game installation because the actual game is executed on the game company’s server and is streamed directly to the client. Nonetheless, this revolutionary approach significantly affects the network load generated by online games. As cloud gaming presents new challenges for both network engineers and the research community, both groups need to be fully conversant with these new cloud gaming platforms. The purpose of this paper is to investigate OnLive, one of the most popular cloud gaming platforms. Our key contributions are: (a) a review of the state-of-the-art of cloud gaming; (b) reverse engineering of the OnLive protocol; and (c) a synthetic traffic model for OnLive.     

Dynamic application placement in the Mobile Cloud Network

To meet the challenges of consistent performance, low communication latency, and a high degree of user mobility, cloud and Telecom infrastructure vendors and operators foresee a Mobile Cloud Network that incorporates public cloud infrastructures with cloud augmented Telecom nodes in forthcoming mobile access networks. A Mobile Cloud Network is composed of distributed cost- and capacity-heterogeneous resources that host applications that in turn are subject to a spatially and quantitatively rapidly changing demand. Such an infrastructure requires a holistic management approach that ensures that the resident applications’ performance requirements are met while sustainably supported by the underlying infrastructure. The contribution of this paper is three-fold. Firstly, this paper contributes with a model that captures the cost- and capacity-heterogeneity of a Mobile Cloud Network infrastructure. The model bridges the Mobile Edge Computing and Distributed Cloud paradigms by modelling multiple tiers of resources across the network and serves not just mobile devices but any client beyond and within the network. A set of resource management challenges is presented based on this model. Secondly, an algorithm that holistically and optimally solves these challenges is proposed. The algorithm is formulated as an application placement method that incorporates aspects of network link capacity, desired user latency and user mobility, as well as data centre resource utilisation and server provisioning costs. Thirdly, to address scalability, a tractable locally optimal algorithm is presented. The evaluation demonstrates that the placement algorithm significantly improves latency, resource utilisation skewness while minimising the operational cost of the system. Additionally, the proposed model and evaluation method demonstrate the viability of dynamic resource management of the Mobile Cloud Network and the need for accommodating rapidly mobile demand in a holistic manner.     

A game attention model for efficient bit rate allocation in cloud gaming

The widespread availability of broadband internet access and the growth in server-based processing have provided an opportunity to run games away from the player into the cloud and offer a new promising service known as cloud gaming. The concept of cloud gaming is to render a game in the cloud and stream the resulting game scenes to the player as a video sequence over a broadband connection. To meet the stringent network bandwidth requirements of cloud gaming and support more players, efficient bit rate reduction techniques are needed. In this paper, we introduce the concept of game attention model (GAM), which is basically a game context-based visual attention model, as a means for reducing the bit rate of the streaming video more efficiently. GAM estimates the importance of each macro-block in a game frame from the player’s perspective and allows encoding the less important macro-blocks with lower bit rate. We have evaluated nine game video sequences, covering a wide range of game genre and a spectrum of scene content in terms of details, motion and brightness. Our subjective assessment shows that by integrating this model into the cloud gaming framework, it is possible to decrease the required bit rate by nearly 25 % on average, while maintaining a relatively high user quality of experience. This clearly enables players with limited communication resources to benefit from cloud gaming with acceptable quality.     

High-resolution gaming: Interfaces,notifications, and the user experience

Advances in technology and display hardware have allowed the resolution of monitors – and video games – to incrementally improve over the past three decades. However, little research has been done in preparation for the resolutions that will be available in the future if this trend continues. We developed a number of display prototypes to explore the different aspects of gaming on large, high-resolution displays.By running a series of experiments, we were not only able to evaluate the benefits of these displays for gaming, but also identify potential user interface and hardware issues that can arise. Building on these results, various interface designs were developed to better notify the user of passive and critical game information as well as to overcome difficulties with mouse-based interaction on these displays. Different display form factors and user input devices are also explored in order to determine how they can further enhance the gaming experience. In many cases, the new techniques can be applied to single-monitor games and solve the same problems in real-world, high-resolution applications.     

Educating the Next Generation of Mobile Game Developers

Mobile gaming is one of the fastest growing segments in the video game industry. Through a partnership between Motorola Laboratories and GamePipe Laboratory at the University of Southern California, we are exploring Linux's capabilities for mobile gaming and to provide developers with an alternative to what is predominantly a Java-based medium. Moving beyond Java lets game developers fully leverage the hardware advances and software capabilities of high-end smart phones     

Proxy‐guided Image‐based Rendering for Mobile Devices

VR headsets and hand‐held devices are not powerful enough to render complex scenes in real‐time. A server can take on the rendering task, but network latency prohibits a good user experience. We present a new image‐based rendering (IBR) architecture for masking the latency. It runs in real‐time even on very weak mobile devices, supports modern game engine graphics, and maintains high visual quality even for large view displacements. We propose a novel server‐side dual‐view representation that leverages an optimally‐placed extra view and depth peeling to provide the client with coverage for filling disocclusion holes. This representation is directly rendered in a novel wide‐angle projection with favorable directional parameterization. A new client‐side IBR algorithm uses a pre‐transmitted level‐of‐detail proxy with an encaging simplification and depth‐carving to maintain highly complex geometric detail. We demonstrate our approach with typical VR / mobile gaming applications running on mobile hardware. Our technique compares favorably to competing approaches according to perceptual and numerical comparisons.     

A point-based rendering approach for real-time interaction on mobile devices

Mobile device is an important interactive platform. Due to the limitation of computation, memory, display area and energy, how to realize the efficient and real-time interaction of 3D models based on mobile devices is an important research topic. Considering features of mobile devices, this paper adopts remote rendering mode and point models, and then, proposes a transmission and rendering approach that could interact in real time. First, improved simplification algorithm based on MLS and display resolution of mobile devices is proposed. Then, a hierarchy selection of point models and a QoS transmission control strategy are given based on interest area of operator, interest degree of object in the virtual environment and rendering error. They can save the energy consumption. Finally, the rendering and interaction of point models are completed on mobile devices. The experiments show that our method is efficient. Supported by the National Natural Science Foundation of China (Grant No. 60873159), the Program for New Century Excellent Talents in University (Grant No. NCET-07-0039), the National High-Tech Research & Development Progrom of China (Grant No. 2006AA01Z333)     

Mobile Cloud Middleware

Mobile Cloud Computing (MCC) is arising as a prominent research area that is seeking to bring the massive advantages of the cloud to the constrained smartphones. Mobile devices are looking towards cloud-aware techniques, driven by their growing interest to provide ubiquitous PC-like functionality to mobile users. These functionalities mainly target at increasing storage and computational capabilities. Smartphones may integrate those functionalities from different cloud levels, in a service oriented manner within the mobile applications, so that a mobile task can be delegated by direct invocation of a service. However, developing these kind of mobile cloud applications requires to integrate and consider multiple aspects of the clouds, such as resource-intensive processing, programmatically provisioning of resources (Web APIs) and cloud intercommunication. To overcome these issues, we have developed a Mobile Cloud Middleware (MCM) framework, which addresses the issues of interoperability across multiple clouds, asynchronous delegation of mobile tasks and dynamic allocation of cloud infrastructure. MCM also fosters the integration and orchestration of mobile tasks delegated with minimal data transfer. A prototype of MCM is developed and several applications are demonstrated in different domains. To verify the scalability of MCM, load tests are also performed on the hybrid cloud resources. The detailed performance analysis of the middleware framework shows that MCM improves the quality of service for mobiles and helps in maintaining soft-real time responses for mobile cloud applications.     

CloudyGame: Enabling cloud gaming on the edge with dynamic asset streaming and shared game instances

Multimedia Tools and Applications - Cloud gaming has emerged as a new computer game delivery paradigm that promises gaming anywhere, anytime, on any device, by running the computer game on a cloud...     

Efficient application scheduling in mobile cloud computing based on MAX–MIN ant system

Combining the advantages of mobile computing and cloud computing, Mobile Cloud Computing (MCC) greatly enriches the types of applications on mobile devices and enhances the quality of service of the applications. Under various circumstances, researchers have put forward several MCC architectures. However, it still remains a challenging task of how to design a reasonable mobile cloud model with efficient application processing structure for some particular environment. This paper firstly presents a Hybrid Local Mobile Cloud Model (HLMCM) with detailed application scheduling structure. Secondly, a scheduling algorithm for HLMCM based on MAX–MIN Ant System is put forward. Finally, the effectiveness and suitability of our proposed algorithms are evaluated through a series of simulation experiments.     

Influence of Different Types of Vibrations on Technical Acceptance of a Mobile Game Aiming for Hedonic Satisfaction

Rapid increases in the smartphone gaming industry have made in-game usability increasingly important. However, industrial usability is still focused on performance although high performance is not necessarily a goal in actual games. Mobile gamers largely want to increase their hedonic satisfaction. So already established usability guidelines can fail in mobile gaming. Focusing on vibrations as a haptic feedback, this study analyzed the influences of intensity and length of vibrations on user perceptions based on the technology acceptance model aiming for hedonic satisfaction when mobile gaming. A smartphone game was modified to generate seven types of vibrations for a human factors experiment with 70 subjects and administered a questionnaire to measure their perceptions of the game influenced by the vibrations. The results show that including vibrations significantly increases the perceived ease of use, perceived usefulness, and cognitive concentration in the game. The stronger vibration intensity significantly improves user perceptions of the usefulness and cognitive concentration, whereas the length of vibration is not a critical factor as long as vibrations exist.     

A modeling and simulation framework for mobile cloud computing

Mobile cloud computing (MCC) is an emerging paradigm for transparent elastic augmentation of mobile devices capabilities, exploiting ubiquitous wireless access to cloud storage and computing resources. MCC aims at increasing the range of resource-intensive tasks supported by mobile devices, while preserving and extending their resources. Its main concerns regard the augmentation of energy efficiency, storage capabilities, processing power and data safety, to improve the experience of mobile users. The design of MCC systems is a challenging task, because both the mobile device and the Cloud have to find energy-time tradeoffs and the choices on one side affect the performance of the other side. The analysis of the MCC literature points out that all existing models focus on mobile devices, considering the Cloud as a system with unlimited resources. Also, to the best of our knowledge, no MCC-specific simulation tool exists. To fill this gap, in this paper, we propose a modeling and simulation framework for the design and analysis of MCC systems, encompassing all their components. The main pillar of the proposed framework is the autonomic strategy consisting of adaptive loops between every mobile devices and the Cloud. The proposed model of the mobile device takes into account online estimations of the actual Cloud performance – not only the nominal values of the performance indicators. At the same time, the model of the Cloud takes into consideration the characteristics of the workload, to adapt its configuration in terms of active virtual machines and task management strategies. Moreover, the developed discrete event simulator is an effective tool for the evaluation of an MCC system as a whole, or single components, considering different classes of parallel jobs.     

Anaglyph video smell presentation using micro-porous piezoelectric film olfactory display

Anaglyph video (i.e., 3D video) is a recent trend in movies and multimedia; the method has also been recently developed for conversion of such videos from traditional 2D screens or by rendering stereoscopic media into 3D video. There have also been many studies regarding movie playing and other types of entertainment that uses olfactory displays or smell generators. These devices are capable of generating a considerable number of different odors with different intensities yet still have some limitations and are not ready for commercial use. In this study, a complete solution is presented for a user to experience olfactory sensations with a displayed video on a PC with auditory and 3D visual effects using a novel olfactory display device based on a micro-porous piezoelectric film that is capable of digitally producing fine particles of scent material with precision, quantity and speed.     

基于电量状态的移动流媒体码率自适应策略

为提升移动流媒体的用户体验质量(quality of experience,QoE)和设备续航时长,提出一种基于移动设备电量状态的Qo E模型,模型的参数包括初始延迟、重新缓冲、平均视频质量、码率切换平滑度以及设备电量状态.在模型的基础上,给出一种基于网络吞吐量,同时又考虑设备电量状态的码率自适应策略.策略能避免客户端...     

A streaming-based solution for remote visualization of 3D graphics on mobile devices

Mobile devices such as personal digital assistants, tablet PCs, and cellular phones have greatly enhanced user capability to connect to remote resources. Although a large set of applications is now available bridging the gap between desktop and mobile devices, visualization of complex 3D models is still a task hard to accomplish without specialized hardware. This paper proposes a system where a cluster of PCs, equipped with accelerated graphics cards managed by the Chromium software, is able to handle remote visualization sessions based on MPEG video streaming involving complex 3D models. The proposed framework allows mobile devices such as smart phones, personal digital assistants (PDAs), and tablet PCs to visualize objects consisting of millions of textured polygons and voxels at a frame rate of 30 fps or more depending on hardware resources at the server side and on multimedia capabilities at the client side. The server is able to concurrently manage multiple clients computing a video stream for each one; resolution and quality of each stream is tailored according to screen resolution and bandwidth of the client. The paper investigates in depth issues related to latency time, bit rate and quality of the generated stream, screen resolutions, as well as frames per second displayed     

Joint optimization method for task scheduling time and energy consumption in mobile cloud computing environment

An unheard of growth in mobile data traffic has drawn attention from academia and industry. Mobile cloud computing is an emerging computing paradigm combining cloud computing and mobile networks to alleviate resource-constrained limitations of mobile devices, which can greatly improve network quality of service and efficiency to make good use of available network resource. Mobile cloud computing not only inherits the advantages of strong computing capacity and massive storage of cloud computing, but also overcomes the time and geographical restrictions, bringing benefits for mobile users to offload complex computation to powerful cloud servers for execution anytime and anywhere. To this end, an optimal task workflow scheduling scheme is proposed for the mobile devices, based on the dynamic voltage and frequency scaling technique and the whale optimization algorithm. Through considering three factors: task execution position, task execution sequence, and operating voltage and frequency of mobile devices, this study makes a tradeoff between performance and energy consumption by solving the joint optimization for task completion time and energy consumption simultaneously. Finally, a series of extensive simulation results has demonstrated and verified the scheme has distinguished performance in terms of efficiency and operational cost, providing feasible solutions to similar optimization problems of mobile cloud computing.     

An efficient dynamic decision-based task optimization and scheduling approach for microservice-based cost management in mobile cloud computing applications

The use of smartphones and mobile devices has increased significantly, as have Mobile Cloud Applications based on cloud computing. These applications are used in various fields, including Augmented Reality, E-Transportation, 2D/3-D Games, E-Healthcare, and Education. While existing cloud-based frameworks provide such services on Virtual Machines, they incur problems such as overhead, lengthy boot time, and high costs. To address these issues, the paper proposes a Dynamic Decision-Based Task Scheduling Approach for Microservice-based Mobile Cloud Computing Applications (MSCMCC) that can run delay-sensitive applications and mobility with less cost than existing approaches. The study focuses on Task Offloading problems on heterogeneous Mobile Cloud servers. It proposes a Task Offloading and Microservices based Computational Offloading (TSMCO) framework to solve Task Scheduling in steps such as Resource Matching, Task Sequencing, and Task Offloading. Experimental results show that the proposed MSCMCC and TSMCO enhance Mobile Server Utilization while minimizing costs and improving boot time, resource utilization, and task arrival time for various applications. Specifically, the proposed system effectively reduces the cost of healthcare applications by 25%, augmented reality by 23%, E-Transport tasks by 21%, and 3-D games tasks by 19%, the average boot-time of microservices applications by 17%, resource utilization by 36%, and tasks arrival time by 16%.