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Awesome CloudGaming / CloudXR Resources

A curated list of papers and open-source resources focused on CloudXR. If you have any additions or suggestions, feel free to contribute.

Table of contents


Books

《云游戏:5G开启数字娱乐新时代》,《云化虚拟现实技术与应用》


Implementations


Papers

Architecture

1. 3D Visualizations inWeb BasedEnvironment

Authors:

Abstract This thesis presents a fully functional remote streaming web-based 3D visualization application, that will enable any device to render interactive 3D graphics in real-time. The application only requires a web browser to work and is not limited by the hardware/software and the physical size of the used device. Our application takes advantage of real-time communication technologies, like WebRTC, and multimedia frameworks, like GStreamer, to stream 3D content through the web browser. We also study the performance limitations of native rendering 3D content on mobile devices, by evaluating the number of objects various mobile devices are capable of rendering, concluding that mobile devices are less adequate to render a high number of polygons. In our experiments, the server completed the rendering, on average, 10% faster than our most powerful smartphone, and rendered 46 300 more objects.

📄 Paper | 💻 Code


2. Cloud gaming: architecture and performance

Authors: R. Shea, Jiangchuan Liu, E. Ngai, Yong Cui

Abstract Recent advances in cloud technology have turned the idea of Cloud Gaming into a reality. Cloud Gaming, in its simplest form, renders an interactive gaming application remotely in the cloud and streams the scenes as a video sequence back to the player over the Internet. This is an advantage for less powerful computational devices that are otherwise incapable of running high quality games. Such industrial pioneers as Onlive and Gaikai have seen success in the market with large user bases. In this article, we conduct a systematic analysis of state-of-theart cloud gaming platforms, and highlight the uniqueness of their framework design. We also measure their real world performance with different types of games, for both interaction latency and streaming quality, revealing critical challenges toward the widespread deployment of Cloud Gaming.

📄 Paper


3. GamingAnywhere: an open cloud gaming system

Authors: Chun-Ying Huang, Cheng-Hsin Hsu, Yu-Chun Chang, and Kuan-Ta Chen

Abstract GamingAnywhere is an open-source clouding gaming platform. In addition to its openness, we design GamingAnywhere for high extensibility, portability, and reconfigurability. GamingAnywhere currently supports Windows and Linux, and can be ported to other OS's including OS X and Android. Table 1 gives the latest supported OS's and versions. Our performance study demonstrates that GamingAnywhere achieves high responsiveness and video quality yet imposes low network traffic. The value of GamingAnywhere, however, is from its openness: researchers, service providers, and gamers may customize GamingAnywhere to meet their needs. This is not possible in other closed and proprietary cloud gaming platforms.

📄 Paper | 🌐 Project Page | 💻 Code


4. GamingAnywhere: An Open-Source Cloud Gaming Testbed

Authors: Chun-Ying Huang, De-Yu Chen, Cheng-Hsin Hsu, and Kuan-Ta Chen

Abstract While cloud gaming opens new business opportunity, it also poses tremendous challenges as the Internet only provides best-effort service and gamers are hard to please. Although researchers have various ideas to improve cloud gaming systems, existing cloud gaming systems are closed and proprietary, and cannot be used to evaluate these ideas. We present GamingAnywhere, the first open-source cloud gaming system, which is extensible, portable, and configurable. GamingAnywhere may be used by: (i) researchers and engineers to implement and test their new ideas, (ii) service providers to develop cloud gaming services, and (iii) gamers to set up private cloud gaming systems. Details on GamingAnywhere are given in this paper. We firmly believe GamingAnywhere will stimulate future studies on cloud gaming and real-time interactive distributed systems.

📄 Paper | 🌐 Project Page | 💻 Code


5. GamingAnywhere—The First Open Source Cloud Gaming System

Authors: CHUN-YING HUANG, National Taiwan Ocean University, Taiwan KUAN-TA CHEN, Academia Sinica, Taiwan DE-YU CHEN, Academia Sinica, Taiwan HWAI-JUNG HSU, Academia Sinica, Taiwan CHENG-HSIN HSU, National Tsing Hua University, Taiwan

Abstract We present the first open source cloud gaming system, called GamingAnywhere. In addition to its openness, we design GamingAnywhere for high extensibility, portability, and reconfigurability. We implement GamingAnywhere on Windows, Linux, OS X, and Android. We conduct extensive experiments to evaluate the performance of GamingAnywhere. Our experimental results indicate that GamingAnywhere is efficient, scalable, adaptable to network conditions, and achieves high responsiveness and streaming quality. GamingAnywhere can be employed by the researchers, game developers, service providers, and end users for setting up cloud gaming testbeds, which, we believe, will stimulate more research innovations on cloud gaming systems and applications.

📄 Paper | 🌐 Project Page | 💻 Code


6. LiveRender: A Cloud Gaming System Based on Compressed Graphics Streaming

Authors: Li Lin Xiaofei Liao Guang Tan Hai Jin Xiaobin Yang Wei Zhang Bo Li

Abstract In cloud gaming systems, the game program runs at servers in the cloud, while clients access game services by sending input events to the servers and receiving game scenes via video streaming. In this paradigm, servers are responsible for all performance-intensive operations, and thus suffer from poor scalability. An alternative paradigm is calledgraphics streaming, in which graphics commands and data are offloaded to the clients for local rendering, thereby mitigating the server's burden and allowing more concurrent game sessions. Unfortunately, this approach is bandwidth consuming, due to large amounts of graphic commands and geometry data. In this paper, we present LiveRender, an open source gaming system that remedies the problem by implementing a suite of bandwidth optimization techniques including intra-frame compression, inter-frame compression, and caching, establishing what we call compressed graphics streaming. Experiments results show that the new approach is able to reduce bandwidth consumption by 52-73% compared to raw graphics streaming, with no perceptible difference in video quality and reduced response delay. Compared with the video streaming approach, LiveRender achieves a traffic reduction of 40-90% with even improved video quality and substantially smaller response delay, while enabling higher concurrency at the server.

📄 Paper | 💻 Code


7. Nebula: Reliable Low-latency Video Transmission for Mobile Cloud Gaming

Authors: Ahmad Alhilal (1), Tristan Braud (1), Bo Han (2), Pan Hui (1) ((1) Hong Kong University of Science and Technology (2) George Mason University)

Abstract Mobile cloud gaming enables high-end games on constrained devices by streaming the game content from powerful servers through mobile networks. Mobile networks suffer from highly variable bandwidth, latency, and losses that affect the gaming experience. This paper introduces Nebula, an end-to-end cloud gaming framework to minimize the impact of network conditions on the user experience. Nebula relies on an end-to-end distortion model adapting the video source rate and the amount of frame-level redundancy based on the measured network conditions. As a result, it minimizes the motion-to-photon (MTP) latency while protecting the frames from losses. We fully implement Nebula and evaluate its performance against the state of the art techniques and latest research in realtime mobile cloud gaming transmission on a physical testbed over emulated and real wireless networks. Nebula consistently balances MTP latency (<140 ms) and visual quality (>31dB) even in highly variable environments. A user experiment confirms that Nebulamaximizes the user experience with high perceived video quality, playability, and low user load.

📄 Paper


8. Next Generation Mobile Cloud Gaming

Authors: Wei Cai, Victor C.M. Leung Min Chen

Abstract With the proliferation of smart mobile devices and broadband wireless networks, the mobile gaming market is rapidly expanding among younger generations due to its ubiquitous entertainment features. Cloud-based mobile computing is a promising technology to address the inherent restrictions of mobile devices, such as limited battery lifetime and computational capacity. In this work, we categorize the current approaches to cloud-based mobile gaming and explicitly define Mobile Cloud Gaming (MCG) 1. Based on its unique features, we propose a framework for next generation MCG systems. Open research issues for MCG are also discussed.

📄 Paper


Business

1. Cloud Pricing Models: Taxonomy, Survey, and Interdisciplinary Challenges

Authors: CAESAR WU, RAJKUMAR BUYYA, and KOTAGIRI RAMAMOHANARAO

Abstract This article provides a systematic review of cloud pricing in an interdisciplinary approach. It examines many historical cases of pricing in practice and tracks down multiple roots of pricing in research. The aim is to help both cloud service provider (CSP) and cloud customers to capture the essence of cloud pricing when they need to make a critical decision either to achieve competitive advantages or to manage cloud resource effectively. Currently, the number of available pricing schemes in the cloud market is overwhelming. It is an intricate issue to understand these schemes and associated pricing models clearly due to involving several domains of knowledge, such as cloud technologies, microeconomics, operations research, and value theory. Some earlier studies have introduced this topic unsystematically. Their approaches inevitably lead to much confusion for many cloud decision-makers. To address their weaknesses, we present a comprehensive taxonomy of cloud pricing, which is driven by a framework of three fundamental pricing strategies that are built on nine cloud pricing categories. These categories can be further mapped onto a total of 60 pricing models. Many of the pricing models have been already adopted by CSPs. Others have been widespread across in other industries. We give descriptions of these model categories and highlight both advantages and disadvantages. Moreover, this article offers an extensive survey of many cloud pricing models that were proposed by many researchers during the past decade. Based on the survey, we identify four trends of cloud pricing and the general direction, which is moving from intrinsic value per physical box to extrinsic value per serverless sandbox. We conclude that hyper-converged cloud resources pool supported by cloud orchestration, virtual machine, Open Application Programming Interface, and serverless sandbox will drive the future of cloud pricing.

📄 Paper


2. Developing Cloud Business Models: A Case Study on Cloud Gaming

Authors: Arto Ojala and Pasi Tyrväinen, University of Jyväskylä

Abstract Cloud computing offers new ways for firms to operate in the global market so that even small firms can compete in markets traditionally dominated by multinational corporations. A case study considers how, over ten years, a small firm developed a successful business model to compete in computer gaming.

📄 Paper


CloudGaming

1. A Cost-Efficient Cloud Gaming System at Scale

Authors: Yiling Xu; Qiu Shen; Xin Li; Zhan Ma

Abstract This article proposes a transparent gaming (TG) cloud system that allows users to play any popular high-end desktop game on the fly over the Internet. Toward this goal, we have introduced the TG-SHARE technology to share the underlying hardware capabilities, particularly for the GPU and the dedicated compression acceleration unit (XCODER). TG-SHARE utilizes offthe- shelf consumer GPUs without resorting to expensive proprietary GPU virtualization technology (e.g., GRID from NVIDIA). XCODER adapts the compression based on the network dynamics, learned gaming behaviors, and hardware resources to significantly reduce bandwidth consumption. Google's webRTC protocol is integrated to offer real-time interaction and ubiquitous access from heterogeneous devices. Compared to the existing cloud gaming vendor using the GRID technology, our TG-SHARE not only reduces the expense per user (i.e., 75 percent hardware cost reduction, 20-40 percent network cost reduction), but also improves the quality of experience with higher rate of frames per second (i.e., 2 x FPS).

📄 Paper


2. An empirical study of cloud gaming

Authors: M. Manzano∗, J. A. Hern ́andez†, M. Urue ̃na†, E. Calle∗

Abstract Online gaming connects players from all over the world together for fun and entertainment, and has been regarded as one of the most profitable and popular Internet services. Besides, there is a growing trend towards moving local applications to remote data centers: this is often referred to as the cloud. With the purpose of studying the impact of Cloud Gaming on the access network load, in this paper we carry out an empirical network traffic analysis of two well-known cloud gaming platforms: On-Live and Gaikai. Traffic traces have been collected and analysed from five different games of both platforms. Cloud gaming has been observed to be remarkably different from traditional online gaming in terms of network load and traffic characteristics. Moreover, the traces have revealed similarities between the two platforms regarding the packet size distribution, and differences concerning the packet inter-arrival times. However, each platform shows a similar traffic pattern for most of the games it serves. Nonetheless, the racing and shooter games considered in this work demand more bandwidth than other game-genres.

📄 Paper


3. Are all games equally cloud-gaming-friendly?: an electromyographic approach

Authors:

Abstract Cloud gaming now makes any computer game playable on a thin client without the previous worries and frustrations about the hardware requirements. It frees players from the need to frequently upgrade their computers as they can now play games that are hosted on remote servers with a broadband Internet connection and a thin client. However, cloud games are intrinsically more susceptible to latency than online games because game graphics are rendered on cloud servers and thin clients do not possess game state information that is required by delay compensation techniques. In this paper, we investigate how the response latency in cloud gaming would affect users' experience and how the impact of latency on players' experience varies among different games. We show that not all games are equally friendly to cloud gaming. That is, the same degree of latency may have very different impacts on a game's quality of experience depending on the game's real-time strictness. We thus develop a model that can predict a game's real-time strictness based on the rate of players' inputs and the game screen dynamics. The model can be used to simultaneously enhance players' gaming experience and optimize the operation cost of data centers.

4. Cloud Computing's Killer App: Gaming

Authors:

Abstract AmD's proposed online supercomputer willhandle gaming graphics so your cellphonewon't have to

5. Cloud Gaming Demystified: An Introduction to the Legal Implications of Cloud-Based Video Games

Authors: Mitchell Longan,* Gaetano Dimita,**

Abstract In this paper, we set out to 'demystify' cloud-based videogaming andits legal implications. We do this in two stages. First, we offer adescriptive analysis of the videogame sector, including relevantmarkets and supply chains. We explain the basics of cloud computingtechnology, traditional videogame technology, and how the twoconverge in cloud-based videogame ecosystems. We also analyzemarket structures for both the cloud and video game industries, aswell as relevant supply chains, in order to understand how thesemarkets will overlap. Based on these analyses, we make predictionsabout how the cloud gaming market will be structured, including abreakdown of three separate models for cloud gaming services: the'layered' model of Gaming-as-a-Service ('GaaS'), the 'integrated'model of GaaS, and the 'consumer infrastructure-as-a-service' model.Finally, we use these three models to analyze how certain intellectualproperty rights, contractual rights, and regulatory issues will developin this novel environment for videogame distribution and access.

📄 Paper


6. Cloud Gaming Platforms: Their impact on the future of the video game industry

Authors:

Abstract How will cloud gaming platforms affect the future progression of the video game industry? Inthis thesis, I analyze how the implementation and further progression of cloud gaming platformswill affect the video game industry in the future, through exploratory research. By using deskresearch and historical data, this thesis aims to express the reshaping that the video gameindustry has been through from its invention to its current state, as well as its future prospects.Based on the framework of Porter's five forces and Suarez' battle for technological dominance, Ihave used a combination of both frameworks firstly to analyze the current state of the videogame industry, as well as, the changes that will occur with the implementation of cloud gamingplatforms. Secondly, the framework is then used to analyze how the different cloud technology,and the companies behind them, compete throughout its lifecycle to gain dominance in theindustry. Porter's five forces gives me the indication that the threat level in the industry willremain the same after the implementation of cloud gaming platforms. While Suarez' battle fortechnological dominance shows that cloud gaming platforms are still in a too early phase toaccurately gauge where it is headed. Aside from these two frameworks, there have also beenconducted semi-structured expert interviews with software developers to get a better grasp ofhow the industry is reaction to cloud gaming platforms. By using the results of these frameworksand the expert interviews, I will then discuss three possible scenarios that could be the futureoutcome of cloud gaming platforms. A key finding in the study indicates that cloud gamingplatforms have a promising future ahead where more companies are investing into them. Thisthesis contributes to existing literature by providing an overview of the current state and anoutline of future prospect for cloud gaming platforms.

📄 Paper


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

Authors: A. Bhojan, Siang Ping Ng, J. Ng, Wei Tsang Ooi

Abstract 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 server and streaming the rendered frames to users. To fulfill its promises, a cloud gaming provider must face three main challenges: reducing the interaction latency, reducing the cloud infrastructure cost, and reducing the network bandwidth demand. One way to reduce interaction latency is to run the game on the edge instead of the cloud. This introduces two additional challenges due to the limited resources available on the edge servers. First, there is a high initialization cost to install a game on the edge server if the game that a player wishes to play is not already installed. Second, an edge server typically has limited computing resources compared to the servers in the cloud. In this work, we address these two issues by proposing CloudyGame, a new software architecture for developing computer games, in which (i) resources are more efficiently shared and managed between different playing instances, and (ii) game assets are streamed on-demand to reduce the initialization cost. CloudyGame is implemented with a popular game engine, and thus any game built on the engine supports CloudyGame out of the box. Our evaluation shows that a game running on CloudyGame architecture needs 70–80% less RAM, VRAM, and CPU than a game using conventional architecture when running with four players. Furthermore, the game asset streaming system reduces the game's initial loading time by 70%. Hence, our cloud gaming architecture is highly scalable and economically deployable to the edge. Further, due to a reduction in resource usage, the CloudyGame architecture would benefit games running in the cloud as well.

📄 Paper


8. Edge Gaming: A Greening Perspective

Authors: Francesco Spinellia,b,∗, Antonio Bazco-Noguerasa, Vincenzo Mancusoa

Abstract We tackle the problem of how to support gaming at the edge of the cellular network. The reduced latency and higher bandwidth that the edge enjoys with respect to cloud-based solutions implies that transferring cloud-based games to the edge could be a premium service for end-users. The goal of this work is to design a scheme compatible with MEC and network slicing principles of 5G and beyond, and which maximizes the utility of a service/infrastructure provider with time-varying edge node capacities due to the access to intermittent renewable energy. We formulate a multi -dimensional integer linear programming problem, proving that it is NP-hard in the strong sense. We prove that our problem is sub-modular and propose an efficient heuristic, GREENING, which considers the allocation of gaming sessions and their migration. For the mentioned scenario, we analyze a wide variety of realistic configurations at the edge, studying how the performance depends on i) whether the games have a static or dynamic workload, ii) the distribution of renewable energy through nodes and time, or iii) the topology of the edge network. Through simulations, we show that our heuristic achieves performance close to that achieved by solving the NP-hard optimization problem, except with extremely lower complexity, and performs up to 25% better than state-of-the-art algorithms.

📄 Paper


9. Rendering Server Allocation for MMORPG Players in Cloud Gaming

Authors: Iryanto Jaya, PictureWentong Cai, PictureYusen Li

Abstract Cloud gaming services enable users with heterogeneous device capabilities to get access to game titles with hardware demanding specifications. While visual quality requirements are to be satisfied by the cloud rendering servers, latency is one of the major problems which arises as most of the tasks are offloaded remotely. Cloud gaming players must experience latency below a certain acceptable limit for the game to be responsive with playable visual quality under limited bandwidth capacity. Playing multiplayer games in the cloud needs to cater for player interactions and their commonality especially if they are playing in the same virtual space. The main characteristic of cloud gaming is that the whole rendering pipeline occurs in the cloud; therefore, rendering optimization by reusing common information across players is possible by taking advantage of multi-view rendering. In this paper, we propose a cloud gaming architecture for MMORPGs which involves hundreds of players as well as online optimization heuristic algorithms on rendering server allocations in order to minimize rendering server rental cost from game provider's point of view. In addition, we also compare the performance of those online heuristics with an offline lower bound in order to observe the scalability of the online scenario.

📄 Paper


10. The Future of Cloud Gaming [Point of View]

Authors: Wei Cai, R. Shea, Chun-Ying Huang, Kuan-Ta Chen, Jiangchuan Liu, Victor C. M. Leung, Cheng-Hsin Hsu

Abstract In the late 2000s, several startups including OnLive [7] and GaiKai [8] started to offer cloud gaming services. Cloud gaming, as illustrated in Fig. 1, refers to the technologies that offload parts of game software from traditional game consoles or personal computers (PCs) to powerful and elastic cloud infrastructures. Cloud gaming makes perfect sense to: 1) gamers, who otherwise have to constantly upgrade their consoles or PCs, which is certainly no fun and costly; 2) cloud service providers, who can sell the already-deployed and idling cloud resources to support the cutting-edge games that are extremely resource hungry; and 3) game developers, who no longer need to spend months to port their games to different platforms. As such, cloud gaming has attracted significant attention from both academia and industry. Initially, given the limited scales of these startups, people were not sure whether cloud gaming could be commercially successful. A fundamental question that came to people, inside and outside the gaming circle, was: Will the three dominating console manufacturers, Microsoft, Nintendo, and Sony, be willing to give up their margin of selling the game consoles? The answer was initially unclear, and many suspected that these console manufacturers would be more than happy to kill cloud gaming in order to remain profitable. The opposite actually happened: Sony acquired GaiKai in 2012 for $380 million, announced the new service PlayStation Now (PS Now) in early 2014, and brought PS Now to parts of the world in 2015. Using PS Now, Sony allows their customers to play hundreds of PlayStation 3 (PS3) games on the latest PlayStation 4 (PS4) consoles without porting the games. Sony has also unveiled a plan to: 1) allow gamers to use other PlayStation consoles and smart TV to access PS Now; and 2) include game titles developed for other generations of PlayStations on PS Now. The emerging PS Now service indicates that cloud gaming has great potential to become the next-generation, universal computer gaming platform. Offering high-quality cloud gaming experience with the remote cloud through the public Internet, however, is no easy task. Current cloud gaming services have leveraged real-time video streaming technologies that have a long history of development. They share certain common characteristics, including high bandwidth demand and real-time constraints. Yet the demands of gaming are often higher than live or on-demand video streaming. Certain cloud gaming services dictate a network bandwidth of about 5 Mb/s for smooth gaming experience, which Corresponding author: Jiangchuan Liu (e-mail: jcliu@sfu.ca).

📄 Paper


11. The Server Allocation Problem for Session-Based Multiplayer Cloud Gaming

Authors: Yunhua Deng, Yusen Li, Ronald Seet, Xueyan Tang, Wentong Cai

Abstract Advances in cloud computing and GPU virtualization are allowing the game industry to move into a cloud gaming era. In this paper, we consider multiplayer cloud gaming (MCG), which is the natural integration of multiplayer online gaming and cloud gaming paradigms. With MCG, a game server and a set of rendering servers for the players need to be located and launched in the clouds for each game session. We formulate an MCG server allocation problem with the objective of minimizing the total server rental and bandwidth cost charged by the cloud to support an MCG session. The MCG server allocation problem is hard to solve optimally. We propose several efficient heuristics to address the problem and carry out theoretical analysis for the proposed hill-climbing algorithm. We conduct extensive experiments using real Internet latency and cloud pricing datasets to evaluate the effectiveness of our proposed algorithms as well as several alternatives. Experimental results show that our best algorithm can achieve near-optimal cost under real-time latency constraints.

📄 Paper


CloudXR

1. A Robust Display Delay Compensation Technique Considering User’s Head Motion Direction for Cloud XR

Authors: Tatsuya Kobayashi, Tomoaki Konno, H. Kato

Abstract Conventionally, it has been difficult to realize both photorealistic and geometrically consistent 3DCG rendering on head mounted displays (HMDs), due to the trade-off between rendering quality and low motion-to-photon latency (M2PL). In order to solve this problem, we propose a novel rendering framework, where the server renders RGB-D images of a 3D model with the optimally arranged rendering viewpoints, and the client HMD realizes geometric compensation of M2PL by employing depth image based rendering (DIBR). Experiments with real smart glasses show that the proposed method can display binocular images closer to the ground truth than the conventional approaches.

2. CloudVR - Secure, Fast and Distributed Virtual Reality Solutions

Authors: Leon Koster

Abstract The graduations goal was to find out: "Which Technology stack(s) for building a cloud Virtual Reality (VR) streaming application satisfies the clients demands (low latency, security, QoE) best ? ". The chosen technology stack is NVIDIA's CloudXR SDK deployed on an Microsoft Azure Server, since it was the only feasible way to provide a working prototype for the client within the project timeframe. The report includes the neccessary theoretical knowledge, the decision making progress behind the prototype, implementation and testing of the prototype and implications of the results of the tests. The prototype in it's final set up had an individual frame latency that was only 1-2 ms higher than the researched barrier of 20ms and fulfilled security demands.

📄 Paper


3. CloudVR: Cloud Accelerated Interactive Mobile Virtual Reality

Authors: Teemu Kämäräinen, M. Siekkinen, Jukka Eerikäinen, Antti Ylä-Jääski

Abstract High quality immersive Virtual Reality experience currently requires a PC setup with cable connected head mounted display, which is expensive and restricts user mobility. This paper presents CloudVR which is a system for cloud accelerated interactive mobile VR. It is designed to provide short rotation and interaction latencies through panoramic rendering and dynamic object placement. CloudVR also includes rendering optimizations to reduce serverside computational load and bandwidth requirements between the server and client. Performance measurements with a CloudVR prototype suggest that the optimizations make it possible to double the server's framerate and halve the amount of bandwidth required and that small objects can be quickly moved at run time to client device for rendering to provide shorter interaction latency. A smallscale user study indicates that CloudVR users do not notice small network latencies (20ms) and even much longer ones (100-200ms) become non-trivial to detect when they do not affect the interaction with objects. Finally, we present a design of CloudVR extension to multi-user scenarios.

📄 Paper


4. Cutting the Cord: Designing a High-quality Untethered VR System with Low Latency Remote Rendering

Authors: Luyang Liu, Ruiguang Zhong, Wuyang Zhang, Yunxin Liu, Jiansong Zhang, Lintao Zhang, M. Gruteser

Abstract This paper introduces an end-to-end untethered VR system design and open platform that can meet virtual reality latency and quality requirements at 4K resolution over a wireless link. High-quality VR systems generate graphics data at a data rate much higher than those supported by existing wireless-communication products such as Wi-Fi and 60GHz wireless communication. The necessary image encoding, makes it challenging to maintain the stringent VR latency requirements. To achieve the required latency, our system employs a Parallel Rendering and Streaming mechanism to reduce the add-on streaming latency, by pipelining the rendering, encoding, transmission and decoding procedures. Furthermore, we introduce a Remote VSync Driven Rendering technique to minimize display latency. To evaluate the system, we implement an end-to-end remote rendering platform on commodity hardware over a 60Ghz wireless network. Results show that the system can support current 2160x1200 VR resolution at 90Hz with less than 16ms end-to-end latency, and 4K resolution with 20ms latency, while keeping a visually lossless image quality to the user.

📄 Paper


5. Edge-Computing-Assisted Virtual Reality Computation Offloading: An Empirical Study

Authors: B. W. Nyamtiga, Airlangga Adi Hermawan, Y. F. Luckyarno, Tae-Wook Kim, Deok-Young Jung, Jin Sam Kwak, Ji-Hoon Yun

Abstract Offloading heavy virtual reality (VR) computational operations to a network edge computation entity is receiving increasing attention as a tool to wirelessly and energy efficiently provide low-end client devices with high-quality and immersive interactive VR services anytime and anywhere across the globe. In this work, we aim to provide an understanding of various characteristics of VR computation offloading through comprehensive experiments conducted using a prototype testbed for edge-assisted VR processing and streaming. First, we investigate the benefits of VR offloading in terms of computational load and power consumption reduction for a client device compared to standalone operation. Next, we measure VR traffic patterns, including frame size and data and packet rates with various settings, such as different resolution and encoding options. We also measure several performance metrics associated with the quality of experience, namely, frame rate, packet loss rate, and image quality, with various configuration settings. Then, we present latency measurement studies and investigate per-component latency with various settings. Furthermore, we report the rigorous experiments performed to study the impacts of latency and motion patterns on the black borders formed due to image reprojection and the overfilling technique used to eliminate these black borders.

📄 Paper


6. Edge Cloud-based Augmented Reality

Authors: Christoph Bachhuber, A. Martinez, R. Pries, Sebastian Eger, E. Steinbach

Abstract A convincing augmented reality (AR) experience requires vast computational resources, in particular for threedimensional mapping of the environment, pose estimation and high-quality rendering of virtual objects. Even today's most powerful mobile devices can not provide such computational resources and consequently limit the achievable quality of the augmentation. To tackle this issue, all computations necessary for AR can be offloaded to the Edge Cloud, such that the mobile device merely acts as a camera and display. This approach introduces additional processing steps, namely video communication, which we carefully evaluate with respect to their influence on the quality of experience and energy consumption. In the evaluation of our prototype, we show that with a Glassto-Glass delay of about 85 ms, our implementation is competitive against state-of-the-art solutions which run completely locally on a mobile device. Most notably, the additional steps required for offloading contribute little delay, which is often overcompensated by the faster computations in the Edge Cloud. A further benefit is that compared to performing all AR processing locally, offloading reduces the energy consumption in smartphones on average by 50 %. Moreover, the computational resources available for the AR application increase by a factor 10 to 100 through offloading. Finally, offloading enables high-quality AR applications even in low-end mobile devices.

7. Mobile VR on edge cloud: a latency-driven design

Authors: Shu Shi, Varun Gupta, Michael Hwang, R. Jana

Abstract In this paper we design and implement MEC-VR, a mobile VR system that uses a Mobile Edge Cloud (MEC) to deliver high quality VR content to today's mobile devices using 4G/LTE cellular networks. Our main contribution is in realizing a low latency control loop that streams VR scenes containing only the user's Field of View (FoV) and a latency-adaptive margin area around the FoV. This allows the clients to render locally at a high refresh rate to accommodate and compensate for the head movements before the next motion update arrives. Compared with prior approaches, our MEC-VR design requires no viewpoint prediction, supports dynamic and live VR content, and adapts to the real-world latency experienced in cellular networks between the MEC and mobile devices. We implement a prototype of MEC-VR and evaluate its performance on a MEC node connected to an LTE testbed. We demonstrate that MEC-VR can effectively stream live VR content up to 8K resolution over 4G/LTE networks and achieve more than 80% of bandwidth savings.

📄 Paper


8. On the Minimization of Glass-to-Glass and Glass-to-Algorithm Delay in Video Communication

Authors: Christoph Bachhuber, E. Steinbach, Martin Freundl, M. Reisslein

Abstract Video cameras are increasingly used to provide realtime feedback in automatic control systems, such as autonomous driving and robotics systems. For such highly dynamic applications, the Glass-to-Glass (G2G) and Glass-to-Algorithm (G2A) latencies are critical. In this paper, we analyze the latencies in a point-to-point video transmission system and propose novel frame skipping and preemption approaches to reduce the G2G and G2A delays. We implement the proposed approaches in a prototype which shows significantly reduced G2G and G2A latencies as well as reduced transmission bitrate requirements compared with traditional video transmission schemes. In our low-delay video communication prototype, a VGA resolution video is transmitted with average G2G and G2A delays of 21.2 and 11.5 milliseconds with off-the-shelf hardware.

📄 Paper


9. OpenUVR: an Open-Source System Framework for Untethered Virtual Reality Applications

Authors: Yunhua Deng, Yusen Li, Ronald Seet, Xueyan Tang, Wentong Cai

Abstract Advancements in heterogeneous computing technologies enable the significant potential of virtual reality (VR) applications. To offer the best user experience (UX), a system should adopt an untethered, wireless-network-based architecture to transfer VR content between the user and the content generator. However, modern wireless network technologies make implementing such an architecture challenging, as VR applications require superior video quality—with high resolution, high frame rates, and very low latency. This paper presents OpenUVR, an open-source framework that uses commodity hardware components to satisfy the demands of interactive, real-time VR applications. OpenUVR significantly improves UX through a redesign of the system stack and addresses the most time-sensitive issues associated with redundant memory copying in modern computing systems. OpenUVR presents a cross-layered VR datapath to avoid redundant data operations and computation among system components, OpenUVR customizes the network stack to eliminate unnecessary memory operations incurred by mismatching data formats in each layer, and OpenUVR uses feedback from mobile devices to remove memory buffers. Together, these modifications allow OpenUVR to reduce VR application delays to 14.32 ms, meeting the 20 ms minimum latency in avoiding motion sickness. As an open-source system that is fully compatible with commodity hardware, OpenUVR offers the research community an opportunity to develop, investigate, and optimize applications for untethered, high-performance VR architectures.

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10. Towards Fully Offloaded Cloud-based AR: Design, Implementation and Experience

Authors: R. Shea, Andy Sun, Silvery Fu, Jiangchuan Liu

Abstract Combining advanced sensors and powerful processing capabilities smart-phone based augmented reality (AR) is becoming increasingly prolific. �e increase in prominence of these resource hungry AR applications poses significant challenges to energy constrained environments such as mobile-phones. To that end we present a platform for offloading AR applications to powerful cloud servers. We implement this system using a thin-client design and explore its performance using the real world application Pokemon Go as a case study. We show that with careful design a thin client is capable of offloading much of the AR processing to a cloud server, with the results being streamed back. Our initial experiments show substantial energy savings, low latency and excellent image quality even at relatively low bit-rates.

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Dataset

1. CGD: A Cloud Gaming Dataset with Gameplay Video and Network Recordings

Authors: Iva Slivar, K. Bačić, Irena Orsolic, Lea Skorin-Kapov, M. Sužnjević

Abstract With advances in network capabilities, the gaming industry is increasingly turning towards offering "gaming on demand" solutions, with cloud gaming services such as Sony PlayStation Now, Google Stadia, and NVIDIA GeForce NOW expanding their market offerings. Similar to adaptive video streaming services, cloud gaming services typically adapt the quality of game streams (e.g., bitrate, resolution, frame rate) in accordance with current network conditions. To select the most appropriate video encoding parameters given certain conditions, it is important to understand their impact on Quality of Experience (QoE). On the other hand, network operators are interested in understanding the relationships between parameters measurable in the network and cloud gaming QoE, to be able to invoke QoE-aware network management mechanisms. To encourage developments in these areas, comprehensive datasets are crucial, including both network and application layer data. This paper presents CGD, a dataset consisting of 600 game streaming sessions corresponding to 10 games of different genres being played and streamed using the following encoding parameters: bitrate (5, 10, 20 Mbps), resolution (720p, 1080p), and frame rate (30, 60 fps). For every combination repeated five times for each game, the dataset includes: 1) gameplay video recordings, 2) network traffic traces, 3) user input logs (mouse and keyboard), and 4) streaming performance logs.

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2. GamingVideoSET: a dataset for gaming video streaming applications

Authors: Nabajeet Barman, Saman Zadtootaghaj, Steven Schmidt, M. Martini, S. Möller

Abstract This paper presents GamingVideoSET1, a dataset consisting of twenty-four uncompressed raw gaming videos of 30 seconds duration, 1080p resolution, and 30 fps for the research community working on gaming video quality assessment. Furthermore, the data set includes subjective quality assessment results for 90 video sequences obtained by encoding six different gaming videos using the H.264/MPEG-AVC codec standard in 15 different resolution-bitrate pairs (three resolution, five bitrates each). In addition to the reference videos, the dataset offers a total of 576 distorted videos in MP4 format, obtained by encoding the videos in 24 different resolution-bitrate pairs, and their objective quality assessment results (average and per-frame) using three video quality assessment metrics.

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3. User generated HDR gaming video streaming : dataset, codec comparison and challenges

Authors: Nabajeet Barman, M. Martini

Abstract Gaming video streaming services have grown tremendously in the past few years, with higher resolutions, higher frame rates and HDR gaming videos getting increasingly adopted among the gaming community. Since gaming content as such is different from non-gaming content, it is imperative to evaluate the performance of the existing encoders to help understand the bandwidth requirements of such services, as well as further improve the compression efficiency of such encoders. Towards this end, we present in this paper GamingHDRVideoSET1, a dataset consisting of eighteen 10-bit UHD-HDR gaming videos and encoded video sequences using four different codecs, together with their objective evaluation results. Additionally, the paper discusses the codec compression efficiency of most widely used practical encoders, i.e., x264 (H.264/AVC), x265 (H.265/HEVC) and libvpx (VP9), as well the recently proposed encoder libaom (AV1), on 10-bit, UHD-HDR content gaming content. Our results show that the latest compression standard AV1 results in the best compression efficiency, followed by HEVC, H.264, and VP9.

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4. Video Coding Tool Analysis and Dataset for Gaming Content

Authors: Xin Zhao, Shankai Liu, Xiang Li, Guichun Li, Xiaozhong Xu

Abstract The gaming market has kept growing significantly in recent years. Driven by multiple technology advances, such as cloud computing and video technologies, new gaming applications, e.g. AR, VR and cloud gaming, are becoming more and more practical and popular. Among different types of gaming, the emergence of cloud gaming is driving the market with enhanced gamer experience as well as new challenges to the services. One of the key technological challenges of gaming applications is the video coding, which is the foundation of several popular gaming applications, including cloud gaming and game live streaming. Comparing to the typical camera captured content and screen content, gaming content presents unique features that directly lead to different preferences on the selection of coding tool sets. To better understand the behaviors of known video coding tools and provide test materials for research and development on future coding tools that benefits more on gaming content, in this paper, a dataset consists of a set of gaming video is proposed together with analysis of the performances of existing coding tools on these materials. It is observed that, several known coding tools are exceptionally beneficial for gaming content and the rational is analyzed in this paper.

Edge 5G

1. A Comprehensive Survey on Mobile Edge Computing: Challenges, Tools, Applications

Authors: Fatema Vhora, Jay Gandhi

Abstract Mobile edge computing (MEC) is an emerging standard where cloud computing services like storage and computing, provide to the edge of networks. MEC has the potential of executing computing-intensive applications such as augmented and virtual reality. It is an essential component in the internet of things (IoT) and 5G architecture that provides a noticeable reduction in latency and energy consumption of mobile devices. This paper covers a comprehensive survey about the MEC concept including MEC Analogue. It presents a different edge paradigm like Fog computing, cloudlet, MEC, along with its architecture. The diverse challenges with its related work are covers during the survey. Simulation tools and challenges for real time implementations are explained. Finally, different MEC Scenarios and applications are discussed.

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2. Computation Offloading Toward Edge Computing

Authors: Li Lin, Xiaofei Liao, Hai Jin, Peng Li

Abstract We are living in a world where massive end devices perform computing everywhere and everyday. However, these devices are constrained by the battery and computational resources. With the increasing number of intelligent applications (e.g., augmented reality and face recognition) that require much more computational power, they shift to perform computation offloading to the cloud, known as mobile cloud computing (MCC). Unfortunately, the cloud is usually far away from end devices, leading to a high latency as well as the bad quality of experience (QoE) for latency-sensitive applications. In this context, the emergence of edge computing is no coincidence. Edge computing extends the cloud to the edge of the network, close to end users, bringing ultra-low latency and high bandwidth. Consequently, there is a trend of computation offloading toward edge computing. In this paper, we provide a comprehensive perspective on this trend. First, we give an insight into the architecture refactoring in edge computing. Based on that insight, this paper reviews the state-of-the-art research on computation offloading in terms of application partitioning, task allocation, resource management, and distributed execution, with highlighting features for edge computing. Then, we illustrate some disruptive application scenarios that we envision as critical drivers for the flourish of edge computing, such as real-time video analytics, smart “things” (e.g., smart city and smart home), vehicle applications, and cloud gaming. Finally, we discuss the opportunities and future research directions.

3. From cloud to edge: a first look at public edge platforms

Authors: Mengwei Xu, Zhe Fu, Xiao Ma, Li Zhang, Yanan Li, Feng Qian, Shangguang Wang, Ke Li, Jingyu Yang, Xuanzhe Liu

Abstract Public edge platforms have drawn increasing attention from both academia and industry. In this study, we perform a first-of-its-kind measurement study on a leading public edge platform that has been densely deployed in China. Based on this measurement, we quantitatively answer two critical yetunexplored questions. First, from end users' perspective, what is the performance of commodity edge platforms compared to cloud, in terms of the end-to-end network delay, throughput, and the application QoE. Second, from the edge service provider's perspective, how are the edge workloads different from cloud, in terms of their VM subscription, monetary cost, and resource usage. Our study quantitatively reveals the status quo of today's public edge platforms, and provides crucial insights towards developing and operating future edge services.

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4. Improving Cloud Gaming Experience through Mobile Edge Computing

Authors: Xu Zhang, Hao Chen, Yangchao Zhao, Zhan Ma, Yiling Xu, Haojun Huang, H. Yin, Dapeng Oliver Wu

Abstract With the development of 4G/5G technology and smart devices, more and more users begin to play games via their mobile devices. As a promising way to enable users to play any games, cloud gaming is proposed to stream game scene rendered remotely in the cloud with the format of video. However, it faces major challenges in terms of long delay and high network bandwidth. To this end, a novel framework named EdgeGame is proposed to improve the cloud gaming experience by leveraging resources in the edge. Compared to existing cloud gaming systems, EdgeGame offloads the computation-intensive rendering to the network edge instead, which can reduce network delay and bandwidth consumption greatly. Moreover, EdgeGame introduces deep reinforcement learning in the edge to adjust the video bitrates adaptively to accommodate the network dynamics. Finally, we implemented a prototype system and compared it with an existing cloud gaming system. The experiments show that EdgeGame can reduce the average network delay by 50 percent and improve user's QoE by 20 percent.

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Latency

1. A Measurement Study on Achieving Imperceptible Latency in Mobile Cloud Gaming

Authors: Teemu Kämäräinen, M. Siekkinen, Antti Ylä-Jääski, Wenxiao Zhang, P. Hui

Abstract Cloud gaming is a relatively new paradigm in which the game is rendered in the cloud and is streamed to an end-user device through a thin client. Latency is a key challenge for cloud gaming. In order to optimize the end-to-end latency, it is first necessary to understand how the end-to-end latency builds up from the mobile device to the cloud gaming server. In this paper we dissect the delays occurring in the mobile device and measure access delays in various networks and network conditions. We also perform a Europe-wide latency measurement study to find the optimal server locations and see how the number of server locations affects the network delay. The results are compared to limits found for perceivable delays in recent human-computer interaction studies. We show that the limits can be achieved only with the latest mobile devices with specific control methods. In addition, we study the expected latency reduction by near future technological development and show that its potential impact is bigger on the end-to-end latency than that of replication of the service and server placement optimization.

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2. A System for Precise End-to-End Delay Measurements in Video Communication.

Authors: Christoph Bachhuber, E. Steinbach

Abstract Ultra low delay video transmission is becoming increasingly important. Video-based applications with ultra low delay requirements range from teleoperation scenarios such as controlling drones or telesurgery to autonomous control of dynamic processes using computer vision algorithms applied on real-time video. To evaluate the performance of the video transmission chain in such systems, it is important to be able to precisely measure the glass-to-glass (G2G) delay of the transmitted video. In this paper1, we present a lowcomplexity system that takes a series of pairwise independent measurements of G2G delay and derives performance metrics such as mean delay or minimum delay etc. from the data. The precision is in the sub-millisecond range, mainly limited by the sampling rate of the measurement system. In our implementation, we achieve a G2G measurement precision of 0.5 milliseconds with a sampling rate of 2kHz.

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3. Delay-Sensitive Video Computing in the Cloud: A Survey

Authors: M. Abdallah, C. Griwodz, Kuan-Ta Chen, G. Simon, Pin-Chun Wang, Cheng-Hsin Hsu

Abstract While cloud servers provide a tremendous amount of resources for networked video applications, most successful stories of cloud-assisted video applications are presentational video services, such as YouTube and NetFlix. This article surveys the recent advances on delay-sensitive video computations in the cloud, which are crucial to cloud-assisted conversational video services, such as cloud gaming, Virtual Reality (VR), Augmented Reality (AR), and telepresence. Supporting conversational video services with cloud resources is challenging because most cloud servers are far away from the end users while these services incur the following stringent requirements: high bandwidth, short delay, and high heterogeneity. In this article, we cover the literature with a top-down approach: from applications and experience, to architecture and management, and to optimization in and outside of the cloud. We also point out major open challenges, hoping to stimulate more research activities in this emerging and exciting direction.

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4. Measuring the latency of cloud gaming systems

Authors: Kuan-Ta Chen, Yu-Chun Chang, P. Tseng, Chun-Ying Huang, C. Lei

Abstract Cloud gaming, i.e., real-time game playing via thin clients, relieves players from the need to constantly upgrade their computers and deal with compatibility issues when playing games. As a result, cloud gaming is generating a great deal of interest among entrepreneurs and the public. However, given the large design space, it is not yet known which platforms deliver the best quality of service and which design elements constitute a good cloud gaming system. This study is motivated by the question: How good is the real-timeliness of current cloud gaming systems? To address the question, we analyze the response latency of two cloud gaming platforms, namely, OnLive and StreamMyGame. Our results show that the streaming latency of OnLive is reasonable for real-time cloud gaming, while that of StreamMyGame is almost twice the former when the StreamMyGame server is provisioned using an Intel Core i7-920 PC. We believe that our measurement approach can be generally applied to PC-based cloud gaming platforms, and that it will further the understanding of such systems and lead to improvements.

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5. The brewing storm in cloud gaming: a measurement study on cloud to end-user latency

Authors: Sharon Choy, B. Wong, G. Simon, C. Rosenberg

Abstract Cloud computing has been a revolutionary force in changing the way organizations deploy web applications and services. However, many of cloud computing's core design tenets, such as consolidating resources into a small number of datacenters and fine-grain partitioning of general purpose computing resources, conflict with an emerging class of multimedia applications that is highly latency sensitive and requires specialized hardware, such as graphic processing units (GPUs) and fast memory. In this paper, we look closely at one such application, namely, on-demand gaming (also known as cloud gaming), that has the potential to radically change the multi-billion dollar video game industry. We demonstrate through a large-scale measurement study that the current cloud computing infrastructure is unable to meet the strict latency requirements necessary for acceptable game play for many end-users, thus limiting the number of potential users for an on-demand gaming service. We further investigate the impact of augmenting the current cloud infrastructure with servers located near the end-users, such as those found in content distribution networks, and show that the user coverage significantly increases even with the addition of only a small number of servers.

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6. The Effects of Latency in Commercial Cloud Video Gaming Services

Authors: V Courtemanche, A Desveaux

Abstract Video games are typically played on a device such as a computer, console, or phone,with most of the computation on the local hardware. Cloud gaming services which take overmost computation have been rising in popularity as a potentially viable alternative to traditionalgaming. However, cloud gaming services are more susceptible to latency, since player inputsare sent to cloud servers, and video is then streamed back to the player's client. Our projectevaluated two recently released cloud gaming services (Blade Shadow and Google Stadia) todetermine how they were affected by increased latency and packet loss. We performed a userstudy with different added latency values to test player performance and quality of experiencefor each service. We then performed network experiments analyzing the effects of addedlatency and packet loss on bitrates. Analysis of 37 users shows that user performance andquality of experience decreased with higher added latency for both services. Shadow usedsignificantly more bandwidth than Stadia but had better graphics quality.

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QoE

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

Authors:H. Ahmadi, Saman Zad Tootaghaj, M. Hashemi, S. Shirmohammadi

Abstract 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.

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2. An Evaluation of QoE in Cloud Gaming Based on Subjective Tests

Authors:M. Jarschel, D. Schlosser, Sven Scheuring, T. Hossfeld

Abstract Cloud Gaming is a new kind of service, which combines the successful concepts of Cloud Computing and Online Gaming. It provides the entire game experience to the users remotely from a data center. The player is no longer dependent on a specific type or quality of gaming hardware, but is able to use common devices. The end device only needs a broadband internet connection and the ability to display High Definition (HD) video. While this may reduce hardware costs for users and increase the revenue for developers by leaving out the retail chain, it also raises new challenges for service quality in terms of bandwidth and latency for the underlying network. In this paper we present the results of a subjective user study we conducted into the user-perceived quality of experience (QoE) in Cloud Gaming. We design a measurement environment, that emulates this new type of service, define tests for users to assess the QoE, derive Key Influence Factors (KFI) and influences of content and perception from our results.

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3. Analysis and QoE evaluation of cloud gaming service adaptation under different network conditions: The case of NVIDIA GeForce NOW

Authors:M. Suznjevic, Iva Slivar, L. Skorin-Kapov

Abstract Cloud gaming represents a highly interactive service whereby game logic is rendered in the cloud and streamed as a video to end devices. While benefits include the ability to stream high-quality graphics games to practically any end user device, drawbacks include high bandwidth requirements and very low latency. Consequently, a challenge faced by cloud gaming service providers is the design of algorithms for adapting video streaming parameters to meet the end user system and network resource constraints. In this paper, we conduct an analysis of the commercial NVIDIA GeForce NOW game streaming platform adaptation mechanisms in light of variable network conditions. We further conduct an empirical user study involving the GeForce NOW platform to assess player Quality of Experience when such adaptation mechanisms are employed. The results provide insight into limitations of the currently deployed mechanisms, as well as aim to provide input for the proposal of designing future video encoding adaptation strategies.

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4. Delay Sensitivity Classification of Cloud Gaming Content

Authors:S. Sabet, Steven Schmidt, Saman Zadtootaghaj, C. Griwodz, Sebastian Möller

Abstract Cloud Gaming is an emerging service that catches growing interestin the research community as well as industry. Cloud Gamingrequire a highly reliable and low latency network to achieve asatisfying Quality of Experience (QoE) for its users. Using a cloudgaming service with high latency would harm the interaction of theuser with the game, leading to a decrease in playing performanceand, thus players frustrations. However, the negative effect of delayon gaming QoE depends strongly on the game content. At a certainlevel of delay, a slow-paced card game is typically not as delaysensitive as a shooting game. For optimal resource allocation andquality estimation, it is highly important for cloud providers, gamedevelopers, and network planners to consider the impact of thegame content. This paper contributes to a better understanding ofthe delay impact on QoE for cloud gaming applications byidentifying game characteristics influencing the delay perception ofthe users. In addition, an expert evaluation methodology to quantifythese characteristics as well as a delay sensitivity classificationbased on a decision tree are presented. The results indicated anexcellent level of agreement, which demonstrates the reliability ofthe proposed method. Additionally, the decision tree reached anaccuracy of 90% on determining the delay sensitivity classes whichwere derived from a large dataset of subjective input quality ratingsduring a series of experiments.

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5. Game Categorization for Deriving QoE-Driven Video Encoding Configuration Strategies for Cloud Gaming

Authors:Iva Slivar, M. Sužnjević, Lea Skorin-Kapov

Abstract Cloud gaming has been recognized as a promising shift in the online game industry, with the aim of implementing the "on demand" service concept that has achieved market success in other areas of digital entertainment such as movies and TV shows. The concepts of cloud computing are leveraged to render the game scene as a video stream that is then delivered to players in real-time. The main advantage of this approach is the capability of delivering high-quality graphics games to any type of end user device; however, at the cost of high bandwidth consumption and strict latency requirements. A key challenge faced by cloud game providers lies in configuring the video encoding parameters so as to maximize player Quality of Experience (QoE) while meeting bandwidth availability constraints. In this article, we tackle one aspect of this problem by addressing the following research question: Is it possible to improve service adaptation based on information about the characteristics of the game being streamed? To answer this question, two main challenges need to be addressed: the need for different QoE-driven video encoding (re-)configuration strategies for different categories of games, and how to determine a relevant game categorization to be used for assigning appropriate configuration strategies. We investigate these problems by conducting two subjective laboratory studies with a total of 80 players and three different games. Results indicate that different strategies should likely be applied for different types of games, and show that existing game classifications are not necessarily suitable for differentiating game types in this context. We thus further analyze objective video metrics of collected game play video traces as well as player actions per minute and use this as input data for clustering of games into two clusters. Subjective results verify that different video encoding configuration strategies may be applied to games belonging to different clusters.

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6. Latency impact on Quality of Experience in a virtual reality simulator for remote control of machines

Authors:

Abstract In this article, we have investigated a VR simulator of a forestry crane used for loading logs onto a truck. We have mainly studied the Quality of Experience (QoE) aspects that may be relevant for task completion, and whether there are any discomfort related symptoms experienced during the task execution. QoE experiments were designed to capture the general subjective experience of using the simulator, and to study task performance. The focus was to study the effects of latency on the subjective experience, with regards to delays in the crane control interface. Subjective studies were performed with controlled delays added to the display update and hand controller (joystick) signals. The added delays ranged from 0 to 30 ms for the display update, and from 0 to 800 ms for the hand controller. We found a strong effect on latency in the display update and a significant negative effect for 800 ms added delay on latency in the hand controller (in total approx. 880 ms latency including the system delay). The Simulator Sickness Questionnaire (SSQ) gave significantly higher scores after the experiment compared to before the experiment, but a majority of the participants reported experiencing only minor symptoms. Some test subjects ceased the test before finishing due to their symptoms, particularly due to the added latency in the display update.

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7. Modeling Gaming QoE: Towards the Impact of Frame Rate and Bit Rate on Cloud Gaming

Authors:Saman Zadtootaghaj, Steven Schmidt, Sebastian Möller

Abstract Recent advances of streaming services and the upcoming new generation of mobile networks, 5G, offering low end-to-end delay as well as high bandwidths, promise a bright future for cloud gaming applications. Cloud gaming, in the contrary to traditional gaming services, suffers not only from system factors on the client, but is also affected significantly by the network, server specification and encoding parameters. In this paper, we present the results of a subjective experiment aiming to investigate the impact of two influencing factors, frame rate and bit rate, on the gaming Quality of Experience. The results reveal that a trade-off between an acceptable video quality and interaction quality exists. In case of very low bit rates, lowering the frame rate can improve the video quality while at some point, jerkiness becomes visible which affects the video quality negatively and the control over the game will be strongly reduced. Furthermore, even though in the gaming community a frame rate of 60 fps is desired, no significant difference for quality ratings, as well as performance ratings, was found between 60 fps and 25 fps. Therefore, it would be highly valuable for service providers to find an ideal strategy for this issue. In addition, we investigate the impact of video encoding on gaming experience dimensions. Finally, a first attempt to model the impact of two influencing factors on overall quality will be presented.

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8. Perceived order in different sense modalities.

Authors:I. Hirsh, C. Sherrick

Abstract

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9. Quality of experience (QoE) in cloud gaming models: A review

Authors:Asif Ali Laghari, Hui He, K. A. Memon, Rashid Ali Laghari, I. A. Halepoto, Asiya Khan

Abstract Cloud gaming is a new way of online gaming, which renders the game data on the cloud side instead of the end user's system and is forwarded via a high-speed network. In cloud gaming; game software and emulators run on the high-speed server of cloud and services available for users on the commercial and free basis. Users can use rendered data of game from the cloud using thin heterogeneous devices via the Internet to play the game anytime and anywhere. The popularity of cloud gaming has increased since the late 2000s which attract the industry and academia. Quality of experience (QoE) domain has been added in cloud gaming models to assess user satisfaction, enjoyment, and needs during online gaming. In this research paper; we survey and analyze the previous cloud gaming models and models and offer aspects of future development; which will help to give the quality of service (QoS) according to service level agreement (SLA) and increase user satisfaction level for cloud gaming, hence, improving the overall QoE.

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10. Subjective quality assessment for cloud gaming

Authors:Abdul Wahab, Nafi Ahmad, M. Martini, J. Schormans

Abstract Using subjective testing, we study the effect of the network parameters, delay and packet loss ratio, on the QoE of cloud gaming. We studied three different games, selected based on genre, popularity, content complexity and pace, and tested them in a controlled network environment, using a novel emulator to create realistic lognormal delay distributions instead of relying on a static mean delay, as used previously; we also used Parsec as a good representative of the state of the art. We captured user ratings on an ordinal Absolute Category Rating scale for three quality dimensions: Video QoE, Game-Playability QoE, and Overall QoE. We show that Mean Opinion Scores (MOS) for the game with the highest levels of content complexity and pace are most severely affected by network impairments. We also show that the QoE of interactive cloud applications rely more on the game playability than the video quality of the game. Unlike earlier studies, the differences in MOS are validated using the distributions of the underlying dimensions. A Wilcoxon Signed-Rank test showed that the distributions of Video QoE and Game Playability QoE are not significantly differen.

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QoS

1. A First Look at the Network Turbulence for Google Stadia Cloud-based Game Streaming

Authors:Xiaokun Xu, Mark Claypool

Abstract While there have been network studies of traditional network games and streaming video, there is less work measuring cloud-based game streaming traffic and none on Google's Stadia. This paper presents experiments that provide a first look – measuring Stadia game traffic for several games, analyzing the bitrates, packet sizes and inter-packet times, and comparing the results to other applications. Results indicate Stadia, unlike traditional network game systems, rapidly sends large packets downstream and small packets upstream, similar to but still significantly different than video and at much higher rates than previous cloud-based game systems or video.

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2. A network analysis on cloud gaming: Stadia, GeForce Now and PSNow

Authors:A. Domenico, Gianluca Perna, Martino Trevisan, L. Vassio, Danilo Giordano

Abstract Cloud gaming is a class of services that promises to revolutionize the videogame market. It allows the user to play a videogame with basic equipment while using a remote server for the actual execution. The multimedia content is streamed through the network from the server to the user. Hence, this service requires low latency and a large bandwidth to work properly with low response time and high-definition video. Three among the leading tech companies, (Google, Sony and NVIDIA) entered this market with their own products, and others, like Microsoft and Amazon, are planning to launch their own platforms in the near future. However, these companies released so far little information about their cloud gaming operation and how they utilize the network. In this work, we study cloud gaming services from the network point of view. We collect more than 200 packet traces under different application settings and network conditions from a broadband network up to poor mobile network conditions, for 3 cloud gaming services, namely Stadia from Google, GeForce Now from NVIDIA and PS Now from Sony. We analyze the employed protocols and the workload they impose on the network. We find that GeForce Now and Stadia use the RTP protocol to stream the multimedia content, with the latter relying on the standard WebRTC APIs. They result bandwidth-hungry and consume up to 45 Mbit/s, depending on the network and video quality. PS Nowinstead uses only undocumented protocols and never exceeds 13 Mbit/s. 4G mobile networks can often sustain these loads, while traditional 3G connections struggle. The systems quickly react to deteriorated network conditions, and packet losses up to 5% do not cause a reduction in resolution.

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3. A survey on quality of service in cloud computing

Authors:M. Jelassi, C. Ghazel, L. Saïdane

Abstract Cloud computing systems enables pay-perusage pricing model for computing services delivered to users across the globe over the internet. Currently the demand for cloud services has increased as enterprises and individuals have now migrated to the cloud and cloud providers need to offer services based on the expected quality requirements. One of the challenges posed by cloud application is quality of service (QoS) management, which is the problem of allocating resources to the applications to guarantee service based on performance, availability and reliability. In this paper, we have presented a survey on the quality of service in cloud computing with respect to techniques used, advantages and disadvantages.

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4. An Analysis of Cloud Gaming Platforms Behavior under Different Network Constraints

Authors:Philippe Graff, Xavier Marchal, T. Cholez, Stéphane Tuffin, B. Mathieu, O. Festor

Abstract With the recent technological evolutions in networks and increased deployment of multi-tier clouds, cloud gaming (CG) is gaining renewed interest and is expected to become a major Internet service in the upcoming years. Many companies have launched powerful platforms such as Google Stadia, Nvidia GeForce Now, Microsoft xCloud, Sony PlayStation Now among others, to attract players. However, for all end-users to fully enjoy their gaming sessions over the wide range of network access qualities, CG platforms must adapt their traffic. In this paper, we present the outcome of real-life measurements performed between April and July 2021 on the four aforementioned CG platforms, configuring different network constraints like packet loss, throughput decrease, latency increase and jitter variation to observe the behavior of these CG platforms under extreme network conditions. Our findings show that the four platforms exhibit different adaptation behaviors. Moreover, many cases result in a degraded QoS, leaving room for further improvements at both application and/or network levels.

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5. Cloud-gaming: Analysis of Google Stadia traffic.

Authors:Marc Carrascosa, B. Bellalta

Abstract Interactive, real-time, and high-quality cloud video games pose a serious challenge to the Internet due to simultaneous high-throughput and low round trip delay requirements. In this paper, we investigate the traffic characteristics of Stadia, the cloud-gaming solution from Google, which is likely to become one of the dominant players in the gaming sector. To do that, we design several experiments, and perform an extensive traffic measurement campaign to obtain all required data. Our first goal is to gather a deep understanding of Stadia traffic characteristics by identifying the different protocols involved for both signalling and video/audio contents, the traffic generation patterns, and the packet size and inter-packet time probability distributions. Then, our second goal is to understand how different Stadia games and configurations, such as the video codec and the video resolution selected, impact on the characteristics of the generated traffic. Finally, we aim to evaluate the ability of Stadia to adapt to different link capacity conditions, including those cases where the capacity drops suddenly. Our results and findings, besides illustrating the characteristics of Stadia traffic, are also valuable for planning and dimensioning future networks, as well as for designing new resource management strategies.

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6. Demystifying the Largest Live Game Streaming Platform via Black-Box Measurement

Authors:Xu Zhang, Kai Yang, Rongqi Zhang, Qilin Fan, Hong Tang, Zhan Ma

Abstract Empowered by today's fast development of e-sports (Electronic Sports) games, more and more people are watching live-game-streaming through various platforms aside from playing by themselves. Understanding the characteristics of these platforms can benefit both the game viewers and the platform. However, the live game streaming platforms in China, which has the largest game market in terms of both the revenue and the total number of gamers in the world, are still under the veil of mystery. In this paper, we present an initial investigation on Douyu, the largest live game streaming platform in China. We inferred the platform's architecture and workflow by analyzing the captured traffic and crawled data. Moreover, we investigated the statistics and patterns from both the broadcasters' and viewers' perspectives. Compared with the world-wide live game streaming platform Twitch, the regional platform Douyu has more regular daily changes in online channels, which can provide insights for resource provisioning in the future system optimization. Based on the measurement, it is found that the top 7.5% of games have attracted 79.5% viewer's attention. Moreover, the number of mobile viewers have exceeded the number of PC viewers, taking up about 64.8% of the total viewer number. As the most popular mobile game in China, the game Arena of Valor (referred to as wzry in Douyu) has more than 4,500 simultaneous online broadcasters and accounting for 12.7% of the overall attention.

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7. Measuring Key Quality Indicators in Cloud Gaming: Framework and Assessment Over Wireless Networks

Authors:O. S. Peñaherrera-Pulla, César Baena, Sergio Fortes Rodriguez, Eduardo Baena, R. Barco

Abstract Cloud Gaming is a cutting-edge paradigm in the video game provision where the graphics rendering and logic are computed in the cloud. This allows a user's thin client systems with much more limited capabilities to offer a comparable experience with traditional local and online gaming but using reduced hardware requirements. In contrast, this approach stresses the communication networks between the client and the cloud. In this context, it is necessary to know how to configure the network in order to provide service with the best quality. To that end, the present work defines a novel framework for Cloud Gaming performance evaluation. This system is implemented in a real testbed and evaluates the Cloud Gaming approach for different transport networks (Ethernet, WiFi, and LTE (Long Term Evolution)) and scenarios, automating the acquisition of the gaming metrics. From this, the impact on the overall gaming experience is analyzed identifying the main parameters involved in its performance. Hence, the future lines for Cloud Gaming QoE-based (Quality of Experience) optimization are established, this way being of configuration, a trendy paradigm in the new-generation networks, such as 4G and 5G (Fourth and Fifth Generation of Mobile Networks).

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8. On the Quality of Service of Cloud Gaming Systems

Authors:Kuan-Ta Chen, Yu-Chun Chang, Hwai-Jung Hsu, De-Yu Chen, Chun-Ying Huang, Cheng-Hsin Hsu

Abstract Cloud gaming, i.e., real-time game playing via thin clients, relieves users from being forced to upgrade their computers and resolve the incompatibility issues between games and computers. As a result, cloud gaming is generating a great deal of interests among entrepreneurs, venture capitalists, general publics, and researchers. However, given the large design space, it is not yet known which cloud gaming system delivers the best user-perceived Quality of Service (QoS) and what design elements constitute a good cloud gaming system.This study is motivated by the question: How good is the QoS of current cloud gaming systems? Answering the question is challenging because most cloud gaming systems are proprietary and closed, and thus their internal mechanisms are not accessible for the research community. In this paper, we propose a suite of measurement techniques to evaluate the QoS of cloud gaming systems and prove the effectiveness of our schemes using a case study comprising two well-known cloud gaming systems: OnLive and StreamMyGame. Our results show that OnLive performs better, because it provides adaptable frame rates, better graphic quality, and shorter server processing delays, while consuming less network bandwidth. Our measurement techniques are general and can be applied to any cloud gaming systems, so that researchers, users, and service providers may systematically quantify the QoS of these systems. To the best of our knowledge, the proposed suite of measurement techniques have never been presented in the literature.

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9. Performance Measurements on a Cloud VR Gaming Platform

Authors:Yen-Chun Li, Chia-Hsin Hsu, Yu-Chun Lin, Cheng-Hsin Hsu

Abstract As cloud gaming and Virtual Reality (VR) games become popular in the game industry, game developers engage in these fields to boost their sales. Because cloud gaming possesses the merit of lifting computation loads from client devices to servers, it solves the high resource consumption issue of VR games on regular clients. However, it is important to know where is the bottleneck of the cloud VR gaming platform and how can it be improved in the future. In this paper, we conduct extensive experiments on the stateof-the-art cloud VR gaming platform–Air Light VR (ALVR). In particular, we analyze the performance of ALVR using both Qualityof-Service and Quality-of-Experience metrics. Our experiments reveal that latency (up to 90 ms RTT) has less influence on user experience compared to bandwidth limitation (as small as 35 Mbps) and packet loss rate (as high as 8%) . Moreover, we find that VR gamers can hardly notice the difference between the gaming experience with different latency values (between 0 and 90 ms RTT). Such findings shed some lights on how to further improve the cloud VR gaming platform, e.g., a budget of up to 90 ms RTT may be used to absorb network dynamics when bandwidth is insufficient.

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10. Playing High-End Video Games in the Cloud: A Measurement Study

Authors:

Abstract Cloud gaming has emerged as a promising approach to more affordable and accessible games. By rendering high-end video games in the cloud and streaming encoded game scenes to players via the broadband networks, users are relieved from downloading or installing game software. With cloud gaming, users can easily play high-end 3-D video games on any devices anytime and anywhere. In this paper, we conducted a comprehensive measurement study of a leading cloud gaming system in China, namely, CloudUnion. Unlike the previous work, our measurement study was based on an in-depth understanding of the internal mechanisms of CloudUnion, and thus we were able to reveal problems that cannot be observed in a black-box approach. We built a dedicated measurement platform, which enables us to study CloudUnion from different views, including the global view, local view, and user view. We also conducted a comparison study with another cloud gaming system, namely, GamingAnywhere. Our measurement results unveil the pros and cons of the current cloud gaming system design, and bring forth important insights about the cloud infrastructure, user behaviors, traffic patterns, user-perceived quality, and so on. Our work will be valuable for the design of future cloud gaming systems.

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11. The Effects of Latency, Bandwidth, and Packet Loss on Cloud-Based Gaming Services

Authors:J. McManus, T. Day, Zachary J Mailloux

Abstract Network bandwidth increases make the concept of cloud-based gaming services apromising alternative to traditional gaming platforms. Cloud-based gaming services do this byprocessing and rendering the game in a cloud server, receiving control input from the client andstreaming the rendered game back to the client akin to video streaming. Network latencypresents a challenge cloud-based gaming services must overcome to provide a comparableexperience to traditional gaming. Measuring the effects of latency on key factors, such as qualityof experience and player performance, can help understand the capabilities of the currentgeneration of cloud-based gaming services. We conduct a cloud-based gaming service userstudy, surveying user's subjective quality of experience and measuring their in-gameperformance and conduct experiments that measure cloud-based gaming services' networkcharacteristics. Analysis of results shows a significant decrease in both quality of experience andplayer performance as latency increases, but latency has little effect on the frame rate or averagethroughput of cloud-based gaming services.

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Streaming

1. Adaptive Bitrate Streaming in Cloud Gaming

Authors: R Domanico

Abstract Cloud gaming streams games as video from a server directly to a client device making it susceptible to network congestion. Adaptive bitrate streaming estimates the bottleneck capacity of a network and sets appropriate encoding parameters to avoid exceeding the bandwidth of the connection. BBR is a congestion control algorithm as an alternative to current loss-based congestion control. We designed and implemented a bitrate adaptation heuristic based on BBR into GamingAnywhere, an open source cloud gaming platform. We conducted a user study and did objective analysis comparing the software with our modifications to the original. Through our user study we found that our adaptive system was less challenging for a player and improved player retention rates. From our objective tests, we also found that there was no statistically significant difference in visual quality or appearance of the tested game.

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2. Design and Implementation of Platforms for Game Streaming

Authors: Jungseok Park, Jinwon Kim, Seungjae Lee, Daejune Lim, Eunju Park, Hankyu Lim

Abstract Game streaming technology allows users to play games by connecting to the cloud without separate installation and to play various games on any device, providing a convenient gaming environment for the user. As the 5G environment has been recently established, slow data transmission and reception speeds, which were disadvantages of game streaming, have been accelerated, and as a result, game streaming services are being actively provided. In this paper, we designed a game platform that would become the basis of the development of game streaming platform and implemented it using Android Studio.

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3. Latency contributors in WebRTC-based remote control system

Authors: S Tanskanen

Abstract WebRTC is a prominent technology that has gained substantial traction in the past few years. All major browsers support it which makes it an attractive choice for a remote control system. However, WebRTC is mostly used for teleconferencing applications and it's feasibility for remote control has not been studied. This thesis studies the latency of a WebRTC-based remote control system. A measurement system is designed and implemented for conducting precise and automated latency measurements. Various setups are tested and different internal components are measured to gain thorough understanding on which parts of the system contribute most to the overall latency. The results form a good basis for further optimization efforts. The measurement system presented in the thesis can be used to validate improvements in the system, and the detailed data on the latency contributions from different components can be used to direct the optimization to the place where results are most easily achievable. Additionally, these results can be used as a guideline when designing a low-latency remote control system.

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4. Optimizing WebRTC for Cloud Streaming of XR

Authors: E Vikberg

Abstract WebRTC is a multi-purpose technology, enabling low-latency peer-to-peer connections to be formed between clients over the internet. In addition to low latency, it provides signaling, and transmission of both binary data messages and multimedia, making it a powerful tool for streaming extended reality (XR) content. This thesis measured the latency of WebRTC streaming of remotely rendered XR content. The latency is broken down into components, and the feasibility of reducing each component is studied, optimizing the stream for as low latency as possible, without compromising stream quality. Measurements were conducted in a local network, and network conditions were adjusted using a software utility. The server-client delay is found to consist of encoding, decoding, rendering, networking, and buffering delays. Movement-to-photon latency also includes display latency as well as control delay consisting of the time it takes to register the controls, time it takes to transmit the controls to the server, and time it takes to render the effect. After jitter buffering, video encoding and decoding delay are minimized, the biggest causes of latency are rendering rate bound delay components. The primary method of further reducing the latency is therefore found to be increasing the rendering rate. This can also help counteract skipping frames in non-optimal network conditions. Limiting jitter buffering to a short duration can also stabilize the stream, while keeping latency limited.

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5. Performance Evaluation of WebRTC-based Video Conferencing

Authors: B. Jansen, Timothy Goodwin, Varun Gupta, F. Kuipers, G. Zussman

Abstract WebRTC has quickly become popular as a video conferencing platform, partly due to the fact that many browsers support it. WebRTC utilizes the Google Congestion Control (GCC) algorithm to provide congestion control for realtime communications over UDP. The performance during a WebRTC call may be influenced by several factors, including the underlying WebRTC implementation, the device and network characteristics, and the network topology. In this paper, we perform a thorough performance evaluation of WebRTC both in emulated synthetic network conditions as well as in real wired and wireless networks. Our evaluation shows that WebRTC streams have a slightly higher priority than TCP flows when competing with cross traffic. In general, while in several of the considered scenarios WebRTC performed as expected, we observed important cases where there is room for improvement. These include the wireless domain and the newly added support for the video codecs VP9 and H.264 that does not perform as expected.

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6. WebRTC - real-time communication for the open web platform

Authors: N Blum, S Lachapelle, H Alvestrand

Abstract IN THIS TIME of pandemic, the world has turned toInternet-based, real-time communication (RTC) asnever before. The number of RTC products has, overthe past decade, exploded in large part because ofcheaper high-speed network access and more powerfuldevices, but also because of an open, royalty-freeplatform called WebRTC.In fact, over the past year, there has been a 100-foldincrease of video minutes received via the WebRTCstack in the anonymous population that has optedinto Google Chrome's statistics. WebRTC can befound in most Internet meeting services, social networks, live-streaming experiences,and even cloud-based gaming products.WebRTC provides RTC capabilitiesto browsers and native apps. An opensource implementation and tutorialsfor this platform can be found athttps://webrtc.org. It includes audioand video codecs, and signal-process-ing functions such as bandwidth esti-mation, noise suppression, and echocancellation.

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Survey

1. A Survey of Interactive Remote Rendering Systems

Authors: Shu Shi, Cheng-Hsin Hsu

Abstract Remote rendering means rendering 3D graphics on a computing device and displaying the results on another computing device connected through a network. The concept was originally developed for sharing computing resources remotely. It has been receiving increasing attention from researchers in both academia and industry in recent years due to the proliferation of cloud computing and mobile devices. In this article, we survey the interactive remote rendering systems proposed in the literature, analyze how to improve the state-of-the-art, and summarize the related technologies. The readers of this article will understand the history of remote rendering systems and obtain some inspirations of the future research directions in this area.

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2. A Survey on Cloud Gaming: Future of Computer Games

Authors: Wei Cai, R. Shea, Chun-Ying Huang, Kuan-Ta Chen, Jiangchuan Liu, Victor C. M. Leung, Cheng-Hsin Hsu

Abstract Cloud gaming is a new way to deliver high-quality gaming experience to gamers anywhere and anytime. In cloud gaming, sophisticated game software runs on powerful servers in data centers, rendered game scenes are streamed to gamers over the Internet in real time, and the gamers use light-weight software executed on heterogeneous devices to interact with the games. Due to the proliferation of high-speed networks and cloud computing, cloud gaming has attracted tremendous attentions in both the academia and industry since late 2000's. In this paper, we survey the latest cloud gaming research from different aspects, spanning over cloud gaming platforms, optimization techniques, and commercial cloud gaming services. The readers will gain the overview of cloud gaming research and get familiar with the recent developments in this area.

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3. A Survey on Mobile Augmented Reality With 5G Mobile Edge Computing: Architectures, Applications, and Technical Aspects

Authors: Yushan Siriwardhana, P. Porambage, Madhusanka Liyanage, M. Ylianttila

Abstract The Augmented Reality (AR) technology enhances the human perception of the world by combining the real environment with the virtual space. With the explosive growth of powerful, less expensive mobile devices, and the emergence of sophisticated communication infrastructure, Mobile Augmented Reality (MAR) applications are gaining increased popularity. MAR allows users to run AR applications on mobile devices with greater mobility and at a lower cost. The emerging 5G communication technologies act as critical enablers for future MAR applications to achieve ultra-low latency and extremely high data rates while Multi-access Edge Computing (MEC) brings enhanced computational power closer to the users to complement MAR. This paper extensively discusses the landscape of MAR through the past and its future prospects with respect to the 5G systems and complementary technology MEC. The paper especially provides an informative analysis of the network formation of current and future MAR systems in terms of cloud, edge, localized, and hybrid architectural options. The paper discusses key application areas for MAR and their future with the advent of 5G technologies. The paper also discusses the requirements and limitations of MAR technical aspects such as communication, mobility management, energy management, service offloading and migration, security, and privacy and analyzes the role of 5G technologies.

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4. Cloud-based XR Services: A Survey on Relevant Challenges and Enabling Technologies

Authors: T. Theodoropoulos, Antonios Makris, Abderrahmane Boudi, T. Taleb, U. Herzog, Luis Rosa, Luís Cordeiro, K. Tserpes, Elena Spatafora, Alessandro Romussi, E. Zschau, Manos N. Kamarianakis, Antonis I Protopsaltis, G. Papagiannakis, Patrizio Dazzi

Abstract In recent years, the emergence of XR (eXtended Reality) applications, including Holography, Augmented, Virtual and Mixed Reality, has resulted in the creation of rather demanding requirements for Quality of Experience (QoE) and Quality of Service (QoS). In order to cope with requirements such as ultra-low latency and increased bandwidth, it is of paramount importance to leverage certain technological paradigms. The purpose of this paper is to identify these QoE and QoS requirements and then to provide an extensive survey on technologies that are able to facilitate the rather demanding requirements of Cloud-based XR Services. To that end, a wide range of enabling technologies are explored. These technologies include e.g. the ETSI (European Telecommunications Standards Institute) Multi-Access Edge Computing (MEC), Edge Storage, the ETSI Management and Orchestration (MANO), the ETSI Zero touch network & Service Management (ZSM), Deterministic Networking, the 3GPP (3rd Generation Partnership Project) Media Streaming, MPEG's (Moving Picture Experts Group) Mixed and Augmented Reality standard, the Omnidirectional MediA Format (OMAF), ETSI's Augmented Reality Framework etc.

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5. Communication versus computation: a survey of cloud gaming approaches

Authors: R. Grigg, R. Hexel

Abstract There still remains many challenges in creating an e�ective and e�cient cloud gaming operation able to handle the new release games of today. There are also many existing paths to creating a cloud gaming architecture. In this paper some of the di�erent approaches, that are beyond that of just remote rendering, are analysed giving insight into the operational approach of each technology. Currently there is a growing number of initiatives in cloud game architectures that vary in signi�cant ways. Although there are many varying technologies, with a lot of promises, the ultimate goal of a cloud game engine is something unique to what has been before. It really is about providing a modular and scalable approach but within a controllable and sandbox like environment.

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6. Discussion on Key Technologies of Cloud Game Based on 5G and Edge Computing

Authors: Yan Zhang, Yicheng Zhang

Abstract With the rapid development of technology andbusiness models, cloud computing has been widely used as amature computing paradigm. Cloud computing provides alayered service system with its powerful computing and storagecapabilities, and the emergence of 5G and edge computing hasmade it possible to provide end users with convenient,multi-platform, access to any time and place. Cloud games arethe cloud computing applications that have emerged in recentyears and are considered as a "killer". However, due to thecurrent game delay control of cloud gaming has not reached anacceptable level, and based on hardware virtualization and costconsiderations, cloud gaming related technologies are still in theexploration stage. Based on the above background, we firstintroduced the background and foundation of cloud games.Then we analyze the advantages of cloud gaming and thecurrent problems. Additionally, this paper attempts to givesolutions to related problems based on 5G and edge computingtechnology, and at the same time summarizes the researchresults and conclusions.

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7. Virtual Reality Gaming on the Cloud: A Reality Check.

Authors: Sihao Zhao, H. Abou-zeid, R. Atawia, Yoga Suhas Kuruba Manjunath, A. B. Sediq, Xiao-Ping Zhang

Abstract Cloud virtual reality (VR) gaming traffic characteristics such as frame size, inter-arrival time, and latency need to be carefully studied as a first step toward scalable VR cloud service provisioning. To this end, in this paper we analyze the behavior of VR gaming traffic and Quality of Service (QoS) when VR rendering is conducted remotely in the cloud. We first build a VR testbed utilizing a cloud server, a commercial VR headset, and an off-the-shelf WiFi router. Using this testbed, we collect and process cloud VR gaming traffic data from different games under a number of network conditions and fixed and adaptive video encoding schemes. To analyze the applicationlevel characteristics such as video frame size, frame inter-arrival time, frame loss and frame latency, we develop an interval threshold based identification method for video frames. Based on the frame identification results, we present two statistical models that capture the behaviour of the VR gaming video traffic. The models can be used by researchers and practitioners to generate VR traffic models for simulations and experiments - and are paramount in designing advanced radio resource management (RRM) and network optimization for cloud VR gaming services. To the best of the authors' knowledge, this is the first measurement study and analysis conducted using a commercial cloud VR gaming platform, and under both fixed and adaptive bitrate streaming. We make our VR traffic datasets publicly available for further research by the community.

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Virtualization

1. Cloud Gaming: Understanding the Support from Advanced Virtualization and Hardware

Authors: R. Shea, Di Fu, Jiangchuan Liu

Abstract Fueled by elastic resource provisioning, reduced costs and unparalleled scalability, cloud gaming brings immense benefits by expanding the user base to the vast number of resource-constrained thin clients. Existing cloud gaming platforms have mainly focused on private, non-virtualized environments with proprietary hardware. Modern public cloud platforms heavily rely on virtualization for efficient resource sharing, whose potentials have yet to be explored. Migrating gaming to a public cloud is non-trivial however, particularly considering the overhead for virtualization and that the GPUs for game rendering has long been an obstacle in virtualization. This paper takes a first step towards bridging the online gaming system and the public cloud platforms. We present a systematic study on the diverse aspects of migrating gaming services to a virtualized cloud environment. To this end, we closely examine the technology evolution for GPU virtualization and pass-through, and measure the performance of both earlier and the advanced solutions available in the market. We then present the design and implementation of a fully virtualized cloud gaming platform with the latest hardware support. We address the issues from each and every module of the platform, including the choice of hardware or software video encoding, the configuration and the detailed power consumption of thin client, and the impact of streaming protocols. We demonstrate that, with the latest hardware and virtualization support, gaming over virtualized cloud can be made possible with careful optimization and integration of the different modules. We also highlight the critical challenges towards full- fledge deployment of gaming services over public virtualized cloud.

2. GPU Virtualization and Scheduling Methods: A Comprehensive Survey

Authors: CHEOL-HO HONG, Queen's University BelfastIVOR SPENCE, Queen's University BelfastDIMITRIOS S. NIKOLOPOULOS, Queen's University Belfast

Abstract The integration of graphics processing units (GPUs) on high-end compute nodes has established a new accelerator-based heterogeneous computing model, which now permeates high performance computing. The same paradigm nevertheless has limited adoption in cloud computing or other large-scale distributed computing paradigms. Heterogeneous computing with GPUs can benefit the Cloud by reducing operational costs and improving resource and energy efficiency. However, such a paradigm shift would require effective methods for virtualizing GPUs, as well as other accelerators. In this survey paper, we present an extensive and in-depth survey of GPU virtualization techniques and their scheduling methods. We review a wide range of virtualization techniques implemented at the GPU library, driver, and hardware levels. Furthermore, we review GPU scheduling methods that address performance and fairness issues between multiple virtual machines sharing GPUs. We believe that our survey delivers a perspective on the challenges and opportunities for virtualization of heterogeneous computing environments.

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3. VGRIS: Virtualized GPU Resource Isolation and Scheduling in Cloud Gaming

Authors: Miao Yu, Chao Zhang, Zhengwei Qi, Jianguo Yao, Yin Wang, Haibing Guan

Abstract To achieve efficient resource management on a graphics processing unit (GPU), there is a demand to develop a framework for scheduling virtualized resources in cloud gaming. In this article, we propose VGRIS, a resource management framework for virtualized GPU resource isolation and scheduling in cloud gaming. A set of application programming interfaces (APIs) is provided so that a variety of scheduling algorithms can be implemented within the framework without modifying the framework itself. Three scheduling algorithms are implemented by the APIs within VGRIS. Experimental results show that VGRIS can effectively schedule GPU resources among various workloads.

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4. Enhancing Cloud Gaming User Experience through Docker Containers in Fog Nodes

Authors: M. Kannan

Abstract The attraction towards cloud gaming has reached to a high intensity in modern days. The proliferation of gassed-up networks and the development in the field of cloud computing has attracted the researches to deep study and identify the gaps in Cloud Gaming to provide high-end quality of gamer experience. In time-horned cloud gaming model, the game scenes are rendered in a sophisticated game server and corresponding game video is generated. The generated game video will be encoded and sent over the network to the thin clients. The thin clients decode the encoded video and stream the video back to the players device. The fundamental requirement of gaming is to provide maximum quality of gamer experience. Cloud gaming suffers in terms of providing Quality of Experience (QoE), because the network transmission of game scenes from cloud game server to gamer device is distant. Since the traditional cloud gaming is deployed in virtual machine there is performance-overhead which also affects the QoE. We endeavour to minimize latency and increase performance in cloud gaming through this paper. The cloud game server will be offloaded to the fog nodes which is present at the edge network of the player based on Node selection algorithm. To increase the performance of cloud gaming, traditional virtual machine is replaced by light-weight containers. The proposed system achieves new methodology by deploying cloud game server through docker containers in fog nodes. Evaluation results has proved that fognode based gaming has minimized the latency and increased the performance of cloud gaming.Fog assisted gaming has shown about 1.3MB increase in terms of TCP transfer rate over cloud gaming.

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5. A Cloud Gaming System Based on User-Level Virtualization and Its Resource Scheduling

Authors: Youhui Zhang, Peng Qu, Cihang Jiang, Weimin Zheng

Abstract Many believe the future of gaming lies in the cloud, namely Cloud Gaming, which renders an interactive gaming application in the cloud and streams the scenes as a video sequence to the player over Internet. This paper proposes GCloud, a GPU/CPU hybrid cluster for cloud gaming based on the user-level virtualization technology. Specially, we present a performance model to analyze the server-capacity and games' resource-consumptions, which categorizes games into two types: CPU-critical and memory-io-critical. Consequently, several scheduling strategies have been proposed to improve the resource-utilization and compared with others. Simulation tests show that both of the First-Fit-like and the Best-Fit-like strategies outperform the other(s); especially they are near optimal in the batch processing mode. Other test results indicate that GCloud is efficient: An off-the-shelf PC can support five high-end video-games run at the same time. In addition, the average per-frame processing delay is 8�19 ms under different image-resolutions, which outperforms other similar solutions.

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6. Placing Virtual Machines to Optimize Cloud Gaming Experience

Authors: Hua-Jun Hong, De-Yu Chen, Chun-Ying Huang, Kuan-Ta Chen, and Cheng-Hsin Hsu

Abstract Optimizing cloud gaming experience is no easy task due to the complex tradeoff between gamer Quality of Experience (QoE) and provider net profit. We tackle the challenge and study an optimization problem to maximize the cloud gaming provider's total profit while achieving just-good-enough QoE. We conduct measurement studies to derive the QoE and performance models. We formulate and optimally solve the problem. The optimization problem has exponential running time, and we develop an efficient heuristic algorithm. We also present an alternative formulation and algorithms for closed cloud gaming services with dedicated infrastructures, where the profit is not a concern and overall gaming QoE needs to be maximized. We present a prototype system and testbed using off-the-shelf virtualization software, to demonstrate the practicality and efficiency of our algorithms. Our experience on realizing the testbed sheds some lights on how cloud gaming providers may build up their own profitable services. Last, we conduct extensive trace-driven simulations to evaluate our proposed algorithms. The simulation results show that the proposed heuristic algorithms: (i) produce close-to-optimal solutions, (ii) scale to large cloud gaming services with 20000 servers and 40000 gamers, and (iii) outperform the state-of-the-art placement heuristic, e.g., by up to 3.5 times in terms of net profits.

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7. ShareRender: Bypassing GPU Virtualization to Enable Fine-grained Resource Sharing for Cloud Gaming

Authors: Wei Zhang† Xiaofei Liao†¶ Peng Li‡ Hai Jin† Li Lin†

Abstract Cloud gaming is promising to provide high-quality game services by outsourcing game execution to cloud so that users can access games via thin clients (e.g., smartphones or tablets). However, existing cloud gaming systems suffer from low GPU utilization in the virtualized environment. Moreover, GPU resources are scheduled in units of virtual machines (VMs) and this kind of coarse-grained scheduling at the VM-level fails to fully exploit GPU processing capacity. In this paper, we present ShareRender, a cloud gaming system that offloads graphics workloads within VMs directly to GPUs, bypassing GPU virtualization. For each game running in a VM, ShareRender starts a graphics wrapper to intercept frame rendering requests and assign them to render agents responsible for frame rendering on GPUs. Thanks to the flexible workload assignment among multiple render agents, ShareRender enables fine-grained resource sharing at the frame-level to significantly improve GPU utilization. Furthermore, we design an online algorithm to determine workload assignment and migration of render agents, which considers the tradeoff between minimizing the number of active server and low agent migration cost. We conduct experiments on real deployment and trace-driven simulations to evaluate the performance of ShareRender under different system settings. The results show that ShareRender outperforms the existing video-streaming-based cloud gaming system by over 4 times.

8. Virtual Machines vs. Containers in Cloud Gaming Systems

Authors:

Abstract In cloud gaming the game is rendered on a distant cloud server and the resulting video stream is sent back to the user who controls the game via a thin client. The high resource usage of cloud gaming servers is a challenge. Expensive hardware including GPUs have to be efficiently shared among multiple simultaneous users. The cloud servers use virtualization techniques to isolate users and share resources among dedicated servers. The traditional virtualization techniques can however inflict notable performance overhead limiting the user count for a single server. Operating-system-level virtualization instances known as containers are an emerging trend in cloud computing. Containers don't need to virtualize the entire operating system still providing most of the benefits of virtualization. In this paper, we evaluate the container–based alternative to traditional virtualization in cloud gaming systems through extensive experiments. We also discuss the differences needed in system implementation using the container approach and identify the existing limitations.