On the 802 11 Turbulence of Nintendo DS

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” * October 2005 ACM Net. Games, Hawthorne, NY

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… ACM Net. Games, Hawthorne, NY 2 October 2005

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 ACM Net. Games, Hawthorne, NY 3 October 2005

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

Outline • Introduction • Background • Experiments • Results • Conclusions ACM Net. Games, Hawthorne, NY (done) (next) 5 October 2005

Nintendo DS • System – Resolution 256 x 192, 260 k colors – Dual ARM processors • • ARM 9 at 67 MHz , ARM 7 at 33 MHz – 4 MBytes RAM – Touch-pad Network – WLAN is IEEE 802. 11 b • • • Short preamble Wireless capacities of 1 Mbps or 2 Mbps, only Ad hoc mode – No IP stack (UDP/TCP) ACM Net. Games, Hawthorne, NY 6 October 2005

Sony PSP • • System – Resolution 480 x 272 pixels, 24 -bit color – Dual MIPS R 4000 processors at 333 MHz – 32 MBytes RAM – Analog joystick Network – WLAN is IEEE 802. 11 b • 1, 2, 5. 5, 11 Mbps • Ad hoc mode and infrastructure mode – IP stack ACM Net. Games, Hawthorne, NY 7 October 2005

Outline • Introduction • Background • Experiments • Results • Conclusions ACM Net. Games, Hawthorne, NY (done) (next) 8 October 2005

Sony PSP Nintendo DS Games Selected Metroid Prime Hunters Ridge Racer World Tour Need for Speed ACM Net. Games, Hawthorne, NY 9 Soccer Super Mario Untold Legends Picto Chat Hotshots Golf October 2005

Experimental Setup Dell Inspiron 8600 Netgear WG 511 802. 11 b/g with Intersil's PRISM GT chipset • • First floor of wooden house Sniffing via Ethereal (v 0. 10. 3) on laptop Three APs visible, but no traffic except beacons Games on WLAN channels 1, 6, 11 ACM Net. Games, Hawthorne, NY • • • 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 10 October 2005

Outline • Introduction • Background • Experiments • Results • Conclusions ACM Net. Games, Hawthorne, NY (done) (next) 11 October 2005

Game Phases ACM Net. Games, Hawthorne, NY 12 October 2005

Nintendo DS ACM Net. Games, Hawthorne, NY vs. 13 Sony PSP October 2005

Frame Sizes Nintendo DS ACM Net. Games, Hawthorne, NY Sony PSP 14 October 2005

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

Percentage of Broadcast Frames Doom all over again? ACM Net. Games, Hawthorne, NY 16 October 2005

Wireless Connection Quality ACM Net. Games, Hawthorne, NY 17 October 2005

Impact on Contending TCP Throughput ACM Net. Games, Hawthorne, NY 18 October 2005

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 ACM Net. Games, Hawthorne, NY 19 October 2005

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 …) ACM Net. Games, Hawthorne, NY 20 October 2005

Acknowledgements ACM Net. Games, Hawthorne, NY 21 October 2005

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/ October 2005 ACM Net. Games, Hawthorne, NY