[Show abstract][Hide abstract] ABSTRACT: Social virtual worlds such as Second Life (SL) are digital representations of the real world where human-controlled avatars evolve and interact through social activities. Understanding the characteristics of virtual worlds can be extremely valuable in order to optimize their design. In this paper, we perform an extensive analysis of SL. We exploit standard avatar capabilities to monitor the virtual world, and we emulate avatar behaviors in order to evaluate user experience. We make several surprising observations. We find that 30% of the regions are never visited during the six-day monitoring period, whereas less than 1% of the regions have large peak populations. Moreover, the vast majority of regions are static, i.e., objects are seldom created or destroyed. Interestingly, we show that avatars interact similarly to humans in real life, gathering in small groups of 2-10 avatars. We also show that user experience is poor. Most of the time, avatars have an incorrect view of their neighbor avatars, and inconsistency can last several seconds, impacting interactivity among avatars.
Preview · Article · Feb 2011 · IEEE/ACM Transactions on Networking
[Show abstract][Hide abstract] ABSTRACT: Second Life (SL) is currently the most popular social virtual world, i.e., a digitalization of the real world where avatars can meet, socialize and trade. SL is managed through a Client/Server (C/S) architecture with a very high cost and limited scalability. A scalable and cheap alternative to C/S is to use a Peer-to-Peer (P2P) approach, where SL users rely only on their own resources (storage, CPU and bandwidth) to run the virtual world. We develop a SL client that allows its users to take advantage of a P2P network structured as a Delaunay overlay. We compare the performance of a P2P and C/S architecture for Second Life, executing several instances of our client over Planetlab and populating a SL region with our controlled avatars. Avatar mobility traces collected in SL are used to drive avatar behaviors. The results show that P2P improves user experience by about 20% compared to C/S (measured in term of consistency). Avatar interactivity is also 5 times faster in P2P than in C/S.