Chapter 10 – Requirements

Publisher Summary This chapter gives an overview of the requirements for networked virtual environments (NVEs) and network games (NGs), and introduces some technologies to measure and mitigate some particular requirements. Consistency in a NVE or NG at a system and user level are also defined. Four network properties that influence consistency: latency, bandwidth, congestion, and connectivity, are also examined in the chapter. It is argued that latency is the main cause of inconsistency, though bandwidth does impact consistency in the sense that it can be a limiting factor. Network latency is often defined by the time it takes a packet to be sent from one host to another. Both latency and bandwidth requirements are then examined showing how to monitor both. A variety of common NVEs and NGs generate traffic. Among the key observations are that traffic is bursty at a microlevel (servers try to be fair by sending all clients information at the same time) and at the macrolevel (users coordinate their motion or other traffic together). A large difference between the bandwidth requirements of many games and social spaces, where the world must be downloaded, is noted. A final issue, which is dealt with is the actual connectivity of hosts. A case study of Burnout™ Paradise is presented in the chapter.