Load balancing and quality of service constrained framework for Distributed Virtual Environments

Distributed Virtual Environments (DVE) have become increasingly popular over the last few years. Examples of DVEs are Massively Multiplayer Online Games (MMOGs), distributed interactive simulations, and shared virtual worlds. The service providers of DVEs need to ensure that certain Quality of Service (QoS) (messages delivered within a threshold delay) is guaranteed for the users participating in the DVE. In addition to ensuring QoS, the service providers want to balance the load on the servers that maintain the DVE. In this paper, we propose a framework for DVEs which provides QoS to the users and balances the load among the servers. Our framework uses the concept of a virtual server which is a piece of software that does the processing for the DVEs. Each region in the DVE is maintained by an overlay of virtual servers. We provide a heuristic that maps the virtual servers to physical servers, balances the load among the servers and ensures that the servers are not overloaded with objects. We also present a heuristic for creating a Degree and Diameter Bounded Multicast Tree of virtual servers for each region in the DVE which guarantees QoS for users in the DVE. We have conducted simulation experiments to evaluate the performance of our proposed framework.