Assessing Latency in Cloud Gaming

With the emergence of cloud computing, diverse types of Information Technology services are increasingly provisioned through large data centers via the Internet. A relatively novel service category is cloud gaming, where video games are executed in the cloud and delivered to a client as audio/video stream. While cloud gaming substantially reduces the demand of computational power on the client side, thus enabling the use of thin clients, it may also affect the Quality of Service through the introduction of network latencies. In this work, we quantitatively examined this effect, using a self-developed measurement tool and a set of actual cloud gaming providers. For the two providers and three games in our experiment, we found absolute increases in latency between approximately 40 ms and 150 ms, or between 85% and 800% in relative terms, compared to a local game execution. In addition, based on a second complementary experiment, we found mean round-trip times ranging from about 30 ms to 380 ms using WLAN and approximately 40 ms to 1050 ms using UMTS between a local computer and globally distributed compute nodes. Bilaterally among the compute nodes, results were in the range from approximately 10 ms to 530 ms. This highlights the importance of data center placement for the provision of cloud gaming services with adequate Quality of Service properties.