The effects of loss and latency on user performance in unreal tournament 2003®

ABSTRACT

The growth in the popularity of interactive network games has increased the importance of a better understanding of the effects of packet loss and latency on user performance. While previous work on network games has studied user tolerance for high latencies and has studied the effects of latency on user performance in real-time strategy games, to the best of our knowledge, there has been no systematic study of the effects of loss and latency on user performance. In this paper we study user performance for Unreal Tournament 2003 (UT2003), a popular first person shooter game, under varying amounts of packet loss and latency. First, we deduced typical real world values of packet loss and latency experienced on the Internet by monitoring numerous operational UT2003 game servers. We then used these deduced values of loss and latency in a controlled networked environment that emulated various conditions of loss and latency, allowing us to monitor UT2003 at the network, application and user levels. We designed maps that isolated the fundamental first person shooter interaction components of movement and shooting, and conducted numerous user studies under controlled network conditions. We find that typical ranges of packet loss have no impact on user performance or on the quality of game play. The levels of latency typical for most UT2003 Internet servers, while sometimes unpleasant, do not significantly affect the outcome of the game. Since most first person shooter games typically consist of generic player actions similar to those that we tested, we believe that these results have broader implications.

REFERENCES

• 1: G. Armitage. An Experimental Estimation of Latency Sensitivity in Multiplayer Quake 3. International Conference on Networks (ICON), Sept. 2003.
• 2: T. Beigbeder, R. Coughlan, C. Lusher, and J. Plunkett. The Effects of Packet Loss and Latency on Player Performance in Unreal Tournament 2003. Major Qualifying Project MQP-MLC-NG03, WPI, May 2004. Advisors M. Claypool and E. Agu.
• 3: Y. W. Bernier. Latency Compensating Methods in Client/Server In-game Protocol Design and Optimization. Game Developers Conference, Feb. 2001.
• 4: P. Bettner and M. Terrano. 1500 Archers on a 28.8: Network Programming in Age of Empires and Beyond. Gamasutra, Mar. 2001.
• 5: Wu-chang Feng , Francis Chang , Wu-chi Feng , Jonathan Walpole, Provisioning on-line games: a traffic analysis of a busy counter-strike server, Proceedings of the 2nd ACM SIGCOMM Workshop on Internet measurment, November 06-08, 2002, Marseille, France [doi>10.1145/637201.637223]
• 6: Tristan Henderson, Latency and User Behaviour on a Multiplayer Game Server, Proceedings of the Third International COST264 Workshop on Networked Group Communication, p.1-13, November 07-09, 2001
• 7: Tom Jehaes , Danny De Vleeschauwer , Toon Coppens , Bart Van Doorselaer , Eva Deckers , W. Naudts , K. Spruyt , R. Smets, Access network delay in networked games, Proceedings of the 2nd workshop on Network and system support for games, p.63-71, May 22-23, 2003, Redwood City, California [doi>10.1145/963900.963906]
• 8: P. Lincroft. The Internet Sucks: Or, What I Learned Coding X-Wing vs. Tie Fighter. Gamasutra, Sept. 1999.
• 9: S. McCreary and k claffy. Trends in Wide Area IP Traffic Patterns: A View from Ames Internet Exchange. ITC Measurement and Modeling of IP Traffic, Sept. 2000.
• 10: Y.-S. Ng. Designing Fast-Action Games for the Internet. Gamasutra, Sept. 1997.
• 11: Lothar Pantel , Lars C. Wolf, On the impact of delay on real-time multiplayer games, Proceedings of the 12th international workshop on Network and operating systems support for digital audio and video, May 12-14, 2002, Miami, Florida, USA [doi>10.1145/507670.507674]
• 12: Christian Schaefer , Thomas Enderes , Hartmut Ritter , Marina Zitterbart, Subjective quality assessment for multiplayer real-time games, Proceedings of the 1st workshop on Network and system support for games, p.74-78, April 16-17, 2002, Bruanschweig, Germany [doi>10.1145/566500.566511]
• 13: Nathan Sheldon , Eric Girard , Seth Borg , Mark Claypool , Emmanuel Agu, The effect of latency on user performance in Warcraft III, Proceedings of the 2nd workshop on Network and system support for games, p.3-14, May 22-23, 2003, Redwood City, California [doi>10.1145/963900.963901]
• 14: J. Smed, T. Kaukoranta, and H. Hakonen. Aspects of Networking in Multiplayer Computer Games. The Electronic Library, 20(2):87--97, 2002.

INDEX TERMS

Primary Classification:
  C. Computer Systems Organization
  C.2 COMPUTER-COMMUNICATION NETWORKS
      C.2.4 Distributed Systems

General Terms:
Experimentation, Performance

Keywords:
latency, loss, network games