Quality of experience driven control of interactive media stream parameters

In recent years, cloud computing has led to many new kinds of services. One of these popular services is cloud gaming, which provides the entire game experience to the users remotely from a server, but also other applications are provided in a similar manner. In this paper we focus on the option to render the application in the cloud, thereby delivering the graphical output of the application to the user as a video stream. In more general terms, an interactive media stream is set up over the network between the user's device and the cloud server. The main issue with this approach is situated at the network, that currently gives little guarantees on the quality of service in terms of parameters such as available bandwidth, latency or packet loss. However, for interactive media stream cases, the user is merely interested in the perceived quality, regardless of the underlaying network situation. In this paper, we present an adaptive control mechanism that optimizes the quality of experience for the use case of a race game, by trading off visual quality against frame rate in function of the available bandwidth. Practical experiments verify that QoE driven adaptation leads to improved user experience compared to systems solely taking network characteristics into account

Qualitative Evaluation of Latency and Packet Loss in a Cloud-based Games

On-demand multimedia services are more popularthan ever and continue to grow. Consumers can now streammusic, movies, television, and video games at the push of abutton. Such services typically require a minimum connectionspeed to support streaming. However, transient network effectssuch as packet loss and delay variation can play a crucial role indetermining the user quality of experience (QoE) in streamingmultimedia systems. This paper will seek to establish thesubjective impact of negative network effects on the userexperience of a popular cloud-based on-demand video gameservice

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

Network bandwidth increases make cloud-based gaming a promising alternative to traditional gaming. Network latency presents a challenge cloud-based gaming services must overcome to provide a comparable experience to traditional gaming. Measuring the effects of latency on quality of experience and player performance can help understand the capabilities of cloud-based gaming services. We conduct a cloud-based gaming user study, surveying user’s quality of experience and measuring their in-game performance and the services’ network characteristics. Analysis of results show a significant decrease in quality of experience and player performance as latency increases, but latency has little effect on the frame rate or average throughput of cloud-based gaming services

Cloud-gaming:Analysis of Google Stadia traffic

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

Latency Thresholds for Usability in Games: A Survey

User interactions in interactive applications are time critical operations;late response will degrade the experience. Sensitivity to delay doeshowever vary greatly with between games. This paper surveys existingliterature on the specifics of this limitation. We find a classificationwhere games are grouped with others of roughly the same requirements.In addition we find some numbers on how long latency is acceptable.These numbers are however inconsistent between studies, indicatinginconsistent methodology or insufficient classification of games andinteractions. To improve classification, we suggest some changes.In general, research is too sparse to draw any strong or statisticallysignificant conclusions. In some of the most time critical games, latencyseems to degrade the experience at about 50 ms

Adaptive Bitrate Streaming in Cloud Gaming

Cloud gaming streams games as video from a server to a client device making it susceptible to network congestion. Adaptive bitrate streaming estimates network capacity and sets 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 our modified version to the original. Through our results, we found that our adaptive system was less challenging for players and improved retention rates and that there was no statistically significant difference in visual quality from objective testing

Mukautuvien videon toisto algoritmien evaluointi obiilipilivipelaamisessa

Mobile cloud gaming has recently gained popularity as a result of improvements in the quality of internet connections and mobile networks. Under stable conditions, current LTE networks can provide a suitable platform for the demanding requirements of mobile cloud gaming. However, since the quality of mobile network connections constantly change, the network may be unable to always provide the best possible service to all clients. Thus, the ability to adapt is necessary for a mobile cloud gaming platform in order to compensate for changing bandwidth conditions in mobile networks. One approach for doing this is to change the quality of the video stream to match the available bandwidth of the network. This thesis evaluates an adaptive streaming method implemented on a mobile cloud gaming platform called GamingAnywhere and provides an alternative approach for estimating the available bandwidth by measuring the signal strength values of a mobile device. Experimentation was conducted in a real LTE network to determine the best approach in reconfiguring the encoder of the video stream to match the bandwidth of the network. The results show that increasing the constant-rate-factor parameter of the video encoder by 12 reduces the necessary bandwidth to about half. Thus, changing this video encoder parameter provides an effective means to compensate for significant changes in the bandwidth. However, high values of the constant-rate-factor parameter can considerably reduce the quality of the video stream. Thus, the frame rate of the video should be lowered if the constant-rate-factor already has a high value.Mobiilipilvipelaaminen on viimeaikoina kerännyt suosiota parantuneiden internet yhteyksien ja mobiiliverkkojen ansioista. Normaali olosuhteissa nykyiset LTE verkot tarjoavat sopivan alustan mobiili pilvipelaamisen koviin vaatimuksiin. Mobiiliverkkojen yhteyden laatu kuitenkin vaihtelee jatkuvasti ja kaikille käyttäjille ei voida aina tarjota parasta mahdollista yhteyttä. Mukautuminen vaihtelevaan yhteyden laatuun on siis tarpeellista pilvipelaamisalustalle. Tämän voi tehdä esimerkiksi muuttamalla videon kuvanlaatua sopivaksi käytössä olevaan kaistaan. Tässä työssä arvioidaan GamingAnywhere alustalle toteutettu mukautuva videon toistomenetelmä ja esitellään vaihtoehtoinen tapa arvioida käytettävissä olevaa kaistaa mittaamalla mobiilisignaalin vahvuutta mobiililaitteessa. Aidossa LTE verkossa suoritettujen kokeiden avulla selvitettiin paras tapa konfiguroida video enkooderi mukautumaan käytettävissä olevaan kaistan määrään. Tuloksista selviää, että constant-rate-factor-parametrin arvon nostaminen kahdellatoista laskee tarvittavan kaistan määrän noin puoleen. Se on siis tehokkain tapa mukautua merkittäviin muutoksiin kaistan leveydessä. Liian suuret constant-rate-factor-parametrin arvot kuitenkin heikentävät kuvanlaatua merkittävästi, joten kuvataajuutta voi myös alentaa jos parametrin arvo on jo liian suuri

Multi-objective Network Opportunistic Access for Group Mobility in Mobile Internet

The integration of existing and emerging heterogeneous wireless networks in mobile Internet is a combination of diverse but complementary wireless access technologies. Satisfying a set of imperative constrains and optimization objectives, access network selection (ANS) for mobile node (MN) is an inherent procedure in mobility management that needs to be solved in a reasonable manner for the whole system to operate in an optimal fashion. However, ANS remains a significant challenge. Because many MNs with distinctive call characteristics are likely to have correlated mobility and may need to perform mobility management at the same time, this paper, with the goal of investigating group mobility solutions, proposes a network opportunistic access for group mobility (NOA-GM) scheme. By analyzing the directional patterns of moving MNs and introducing the idea of opportunistic access, this scheme first identifies underloaded access networks as candidates. Then, the candidates are evaluated using normalized models of objective and subjective metrics. On this basis, the ANS problem for group mobility can be conducted as a multiobjective combination optimization and then transferred to a signal-objective model by considering the optimization of the performance of the whole system as a global goal while still achieving each MN\u27s performance request. Using an improved genetic algorithm with newly designed evolutionary operators to solve the signal-objective model, an optimal result option for ANS for group mobility is achieved. Simulations conducted on the NS-2 platform show that NOA-GM outperforms the compared schemes in several critical performance metrics

Network Traffic Adaptation For Cloud Games

With the arrival of cloud technology, game accessibility and ubiquity have a bright future; Games can be hosted in a centralize server and accessed through the Internet by a thin client on a wide variety of devices with modest capabilities: cloud gaming. However, current cloud gaming systems have very strong requirements in terms of network resources, thus reducing the accessibility and ubiquity of cloud games, because devices with little bandwidth and people located in area with limited and unstable network connectivity, cannot take advantage of these cloud services. In this paper we present an adaptation technique inspired by the level of detail (LoD) approach in 3D graphics. It delivers multiple platform accessibility and network adaptability, while improving user's quality of experience (QoE) by reducing the impact of poor and unstable network parameters (delay, packet loss, jitter) on game interactivity. We validate our approach using a prototype game in a controlled environment and characterize the user QoE in a pilot experiment. The results show that the proposed framework provides a significant QoE enhancement