Lag Compensation for First-Person Shooter Games in Cloud Gaming

Abstract

Abstract. Cloud gaming is an emerging technology that combines cloud computing with computer games. Compared to traditional gaming, its core advantages include ease of development/deployment for developers, and lower technology costs for users given the potential to play on thin client devices. In this chapter, we firstly describe the approach, and then focus on the impact of latency, known as lag, on Quality of Experience, for so-called First Person Shooter games. We outline our approach to lag compensation whereby we equalize within reason the up and downlink delays in real-time for all players. We describe the testbed in detail, the open source Gaming Anywhere platform, the use of NTP to synchronise time, the network emulator and the role of the centralized log server. We then present results that firstly validate the mechanism and also use small scale and preliminary subjective tests to assess and prove its performance. We conclude the chapter by outlining ongoing and future work.

A Survey and Taxonomy of Latency Compensation Techniques for Network Computer Games

“…Li et al [90] implement outgoing delay for a cloud-based game platform where the amount delayed is inversely proportional to the latency for each client. They propose a maximum threshold to avoid extremely high latencies that might be required to accommodate some clients.…”

“…For performance, outgoing delay can improve fairness for irst-person shooter players for up to 400 milliseconds of latency, evening-out a diference of about 30% in performance between two players [149]. For player Quality of Experience, outgoing delay can improve perceived fairness by 2 points on a 5 point scale for 80 milliseconds of latency [90].…”

“…The maximum total target delay threshold is adjusted depending upon game type.Brun et al[14] propose using outgoing delay in servers so as to manage fairness across clients with diferent latencies.Wikstrand et al[144] describe an łinput buferingž scheme which uses outgoing delay to add latency to outgoing messages to other players so as to equalize their arrival times (they consider a peer-to-peer architecture).Kaiser et al[73] implement outgoing delay by concatenating game update messages at the client into one larger packet for an intended delay period before sending to the server. The server does something similar for updates to the clients.Li et al[90] implement outgoing delay for a cloud-based game platform where the amount delayed is inversely proportional to the latency for each client. They propose a maximum threshold to avoid extremely high latencies that might be required to accommodate some clients.…”

An Overview of the Networking Issues of Cloud Gaming

“…Overall, 23 pieces of literature were selected to identify issues and challenges related to networking that currently affect cloud gaming. The identified issues and challenges are quality of service (QoS) and quality of experience (QoE) [17]- [21], latency [20], [22]- [30], bandwidth [20], [24], [26], [27], [31]- [33], delay [17], [23], [27], [31], [34]- [39], packet loss [17], [19], [22], [30], the cost of providing the service [31]- [33], complexity (video encoding, compression, and game content) [20], [34], [36], [38], and graphics quality [23], [34]- [36]. Figure 2 presents these issues and challenges along with the number of corresponding literature mainly cited to discuss them.…”

“…One challenge of cloud gaming is its need for a sufficient level of network QoS or quality of service, which also affects the users' QoE or quality of experience. There are various network QoS factors that, if degraded, may negatively impact the user's QoE or experience when using cloud gaming [17]- [19]. For QoS, cloud gaming providers should be able to provide high constant bandwidth and low latency [20].…”