The Mirrored Server (MS) architecture uses multiple mirrored servers across multiple locations to alleviate the bandwidth bottleneck in the Client/Server (C/S) architecture. Each mirror receives and multicasts player updates to the others, simulates the game, and disseminates the new game state to players. However, keeping the game state consistent between mirrors in the presence of network delay, and maintaining game responsiveness requires each server in MS to simulate the game multiple times for each game update, and additional times in the event of costly rollbacks. In this paper we propose the Enhanced Mirrored Server (EMS) architecture. Like in the Peer-to-Peer architecture, EMS allows peers to exchange updates directly, resulting in a higher tolerance to delay at the mirrors. We propose using bucket synchronization in the mirrors so that each server in EMS simulates the game only once for each update and does not require rollbacks. The server disseminates updates to clients only in the event of inconsistency, and thus its outgoing bandwidth is lower than in MS. Our EMS uses cryptographic techniques to provide security equivalent to C/S, and prevents the timestamp cheat possible in MS. Our analytical analysis and simulations show the advantages of EMS over MS.

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This paper proposes the Networked Game Mobility Model (NGMM), for synthesising mobility in First-Person-Shooter (FPS) networked games. Current networked game research focuses on modelling low-level aspects, such as packet inter-arrival times and packet sizes, to optimise network traffic and efficient use of gaming servers. Due to the increasing popularity of multiplayer online games, the need has arisen to develop more realistic models. NGMM is such a model that utilises application level aspects of networked game traces to statistically model FPS games. It is believed that an understanding of the application level aspect (e.g. mobility and user actions) of the network is necessary to derive the causality of increasing workloads on the servers, particularly in response to increasing online game popularity. To evaluate the performance of the model simulations, comparisons are made between the original game traces, the Random Way Point Model and NGMM. Analyses of the comparative simulation results show that NGMM is capable of closely matching actual game traces. The incorporation of application level knowledge, performance boundaries of current optimisation techniques, including dead-reckoning and interest management, are also effectively ascertained in this research. This is particularly significant as current models are unable to evaluate their impact with optimisation techniques.

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Mobile ad-hoc networks (MANETs) are dynamic and multi-hop in nature. As nodes continually join and leave the MANET, managing the problem of address conflicts is particularly challenging. In the past, researchers have gone to great lengths to ensure that nodes are assigned unique addresses and various protocols and policies have been designed to resolve address conflicts. In this paper, we argue that current solutions, originally designed for static wired networks, put unnecessary stress on the dynamic operation of a MANET. To solve, this problem, we present a MANET that can continue to operate even when there are conflicting addresses. Unlike previous solutions, our technique does not break applications by requiring nodes to renumber. Further, the overheads introduced by traditional address allocation and maintenance protocols are removed. All these improvements are effected by introducing of a new routing sub-layer that enables a reactive routing protocol to route packets through a MANET that is experiencing address conflicts. This routing sub-layer provides features such as conflict avoidance forwarding, conflict notification, and enhanced address resolution. Disciplines Physical Sciences and Mathematics