DESIGN AND TEST OF THE CROSS-FORMAT SCHEMA PROTOCOL (XFSP) FOR NETWORKED VIRTUAL ENVIRONMENT
by
Ekrem Serin-Lieutenant Junior Grade, Turkish Navy
March 2003
Advisor : Don Brutzman
Co Advisor : Joseph Sullivan

A Networked Virtual Environment (Net-VE) is a distributed software system in which multiple users interact with each other in real time even though these users may be located around the world [Zyda 99]. Net-VEs gained first attention through a variety of DOD and Academic research projects. After release of the multiplayer game DOOM, the gaming industry captured the idea of interactive multiplayer games. Today there are many popular Internet-based multiplayer games available.

Effective networking of diverse entities and systems is a common problem for Networked Virtual Environments. In order to communicate with other entities a variety of communication protocols are used. Historically these communication protocols are “hard coded” into the software system and all nodes that participate in the environment must identically implement the protocols to interact with others. These communication protocols require authoring and compiling by a trained programmer. When the compiling process is introduced to the networked virtual environment, it detracts the extensibility and dynamicism of the system.

This thesis presents the design and development of a Networked Virtual Environment model that uses Cross Format Schema Protocol (XFSP). With this work we show that a networked simulation can work for 24 hours a day and 7 days a week with an extensible schema based networking protocol and it is not necessary to hard code and compile the protocols into the networked virtual environments. Furthermore, this thesis presents a general automatic protocol handler for schema-defined XML document or message. Additionally, this work concludes with idea that protocols can be loaded and extended at runtime, and can be created with different-fidelity resolutions, resulting in swapping at runtime based on distributed state.