1. On the 802.11 Turbulence * of Nintendo DS and Sony PSP Hand-held Network Games Mark Claypool Computer Science Department Worcester Polytechnic Institute http://www.cs.wpi.edu/~claypool/papers/hand-held/ * The term “footprint" is often used in systems work in the context of the basic size a piece of memory of some software. In a network, the size and distribution of packets over time is important, hence the word “turbulence”

2. October 2005 ACM NetGames, Hawthorne, NY2 Motivation (1 of 2) Computer game sales in U.S. on par with Hollywood box office [ESA – 2005, National Organization of Theatre Owners – 2005] For frequent game players, 43% play online [ESA - 2004] Through 2004, hand-helds primarily single-player Spring 2005, Sony PSP and Nintendo DS released and support multiple players –Using IEEE 802.11 (WLAN) Significant, since WLAN increasingly deployed –Dartmouth, Logan Airport, Philadelphia, my house…

3. October 2005 ACM NetGames, Hawthorne, NY3 Motivation (2 of 2) Poor WLAN connections degrade all [Heusse et al. 2003, Bai and Williamson 2004, Gretarsson 2005] –Equal access means poor connection becomes bottleneck There have been numerous studies of popular PC games [Borella 2000, Feng et al. 2002, Faerber 2002, Lang et al. 2004] and consoles [Lang et al 2005] To the best of our knowledge, none on new hand-helds

4. October 2005 ACM NetGames, Hawthorne, NY4 Questions Turbulence for hand-held network games? –Characterizing frame sizes and inter frame times 1st step for building models Turbulence differs across hand-helds (PSP vs. DS)? –If not, then can concentrate on one hand-held Turbulence differs across games (Metroid vs. Mario)? –If not, then can concentrate on one game Turbulence differs from PC games? –If not, then can re-use mature models for PC games Hand-helds interfere with other wireless traffic? –If yes, then plan accordingly

5. October 2005 ACM NetGames, Hawthorne, NY5 Outline Introduction(done) Background(next) Experiments Results Conclusions

6. October 2005 ACM NetGames, Hawthorne, NY6 Nintendo DS System –Resolution 256x192, 260k colors –Dual ARM processors ARM 9 at 67 MHz, ARM 7 at 33 MHz –4 MBytes RAM –Touch-pad Network –WLAN is IEEE 802.11b Short preamble Wireless capacities of 1 Mbps or 2 Mbps, only Ad hoc mode –No IP stack (UDP/TCP)

7. October 2005 ACM NetGames, Hawthorne, NY7 Sony PSP System –Resolution 480x272 pixels, 24-bit color –Dual MIPS R4000 processors at 333 MHz –32 MBytes RAM –Analog joystick Network –WLAN is IEEE 802.11b 1, 2, 5.5, 11 Mbps Ad hoc mode and infrastructure mode –IP stack

8. October 2005 ACM NetGames, Hawthorne, NY8 Outline Introduction(done) Background(done) Experiments(next) Results Conclusions

9. Metroid Prime Hunters Ridge RacerSuper MarioPicto Chat Need for SpeedWorld Tour Soccer Untold LegendsHotshots Golf Nintendo DS Sony PSP Games Selected

10. October 2005 ACM NetGames, Hawthorne, NY10 Experimental Setup First floor of wooden house Sniffing via Ethereal (v0.10.3) on laptop Three APs visible, but no traffic except beacons Games on WLAN channels 1, 6, 11 For each game –Single player to gain familiarity, then two-player –Three runs, gather all data For two games –Three wireless locations: Bad, Good, Excellent For one game –Bulk download on PC Dell Inspiron 8600 Netgear WG511 802.11b/g with Intersil's PRISM GT chipset

11. October 2005 ACM NetGames, Hawthorne, NY11 Outline Introduction(done) Background(done) Experiments(done) Results(next) Conclusions

12. October 2005 ACM NetGames, Hawthorne, NY12 Game Phases

13. October 2005 ACM NetGames, Hawthorne, NY13 Nintendo DS vs. Sony PSP

14. October 2005 ACM NetGames, Hawthorne, NY14 Frame Sizes Nintendo DSSony PSP

15. October 2005 ACM NetGames, Hawthorne, NY15 Inter Frame Times Nintendo DS Sony PSP Why are there so few frames at 0 for some PSP games?

16. October 2005 ACM NetGames, Hawthorne, NY16 Percentage of Broadcast Frames Doom all over again?

17. October 2005 ACM NetGames, Hawthorne, NY17 Wireless Connection Quality

18. October 2005 ACM NetGames, Hawthorne, NY18 Impact on Contending TCP Throughput

19. October 2005 ACM NetGames, Hawthorne, NY19 Conclusions Hand-held games frequent sends of small data –Payloads less than 100 bytes –Inter frame times (non-ACKS) less than 20 msec –Like PC and console games, but more frequent Nintendo DS games similar to each other, while Sony PSP games vary considerably Nintendo DS games different than Sony PSP games –DS games have smaller frames –Some PSP send mostly broadcast Some game phases may adversely affect throughput for contending applications

20. October 2005 ACM NetGames, Hawthorne, NY20 Future Work Multiple-players –Tested 2, games support 2-8, systems 2-16 Turbulence during other game phases –Synchronization phase? –Size and duration of phases? Interaction with other traffic –Same channel, overlapping channel Infrastructure mode –Wide-Area network (loss, latency …)

21. October 2005 ACM NetGames, Hawthorne, NY21 Acknowledgements

22. On the 802.11 Turbulence of Nintendo DS and Sony PSP Hand-held Network Games Mark Claypool Computer Science Department Worcester Polytechnic Institute http://www.cs.wpi.edu/~claypool/papers/hand-held/