A Survey of Routing Techniques for Mobile Collaborative Virtual Environment Applications <s> Backgrounds and Related Works <s> In this paper we make use of automatically generated logs of user activity from 6 meetings held using the MASSIVE-1 virtual reality tele-conferencing system to determine a number of characteristics of user movement and world transition. These results are applied to a consideration of four issues for CVE system design and resource requirements: the amount of network bandwidth and computation required to handle movement within worlds; the degree of look-ahead required when moving; whether world transitions by groups of participants could benefit from special handling (e.g. some form of multicast state-transfer); and whether caching of world state would be useful in these contexts. In each case the implications are quantified for the meetings analysed. <s> BIB001 </s> A Survey of Routing Techniques for Mobile Collaborative Virtual Environment Applications <s> Backgrounds and Related Works <s> Wireless communication systems are becoming the new enabling technology for accessing, sharing and processing data. It is easy to foresee that in the near future users will access the Internet through wireless PDA, while roaming from one place to another. Mobile ad-hoc networks (MANET) are peer-to-peer wireless networks that do not rely on the presence of a wired interconnection infrastructure. Apart from more traditional applications in the military field as well as in disaster recovery and emergency situations, MANET may represent an interesting possibility for personal communications and interaction among mobile users. We identify some possible fields of application for such wireless systems, identifying advantages and drawbacks. We also present a prototype application where MANETs are used in order to provide a distributed image processing service. <s> BIB002
The main focus in this survey is mobile collaborative virtual environment; however, since we believe there is a need to highlights the most influence works related to virtual environment systems occurred in the past 40 years in order to give credits to founder researches. The topic of virtual environment starts in the late 1950's [1] pioneering the concern to change the way people interacted with computers and makes possible virtual reality. Flight simulator  was introduced as one of the most significant antecedents of virtual reality. After that a number of studies have led the implication of human-computer interaction applications. In this section we provide an overview of several desktop CVE systems ranging from military training combat (land, earth, sea) BIB002 to commercial application  , [13] to multiplayer games [12] , BIB001 , and virtual shopping mall  , etc. We classify our studied CVEs applications into two main categories: peer-to-peer and client server models. CVEs designers can choose one model, or they can 'mix' both models, using peer-to-peer for some aspects of their design, and client-server for others. Figure  2 depicts the main communication architecture solutions used in the literature to develop CVEs applications. Most of the studied CVEs systems were developed either for academic or commercial applications. Here we discuss some of them.