International Journal of Advanced Media and Communication http://www.inderscience.com/browse/index.php?journalID=67&year=2010&vol=4&issue=4 Inderscience Publishers Ltd en-uk International Journal of Advanced Media and Communication 1462-4613 1741-8003 © 2010 Inderscience Publishers Ltd editor@inderscience.com https://www.inderscience.com/images/files/coverImgs/ijamc_scoverijamc.jpg http://www.inderscience.com/browse/index.php?journalID=67&year=2010&vol=4&issue=4 http://www.inderscience.com/link.php?id=36833 As IEEE 802.11 WLANs are widely deployed and the popularity of computer games continues increasing, real-time multiplayer games are increasingly played over 802.11 networks. In this paper, we consider the issues of games over 802.11 wireless networks and give a framework to study this kind of applications. A multiplayer game traffic model is produced using Quake 4 as an example. By introducing IEEE 802.11 MAC model, we show how the performance changes as the number of players increases including throughout, delay, jitter and Mean Opinion Score (MOS). Several different network scenarios then are considered. The issue of bottleneck effect at the AP is identified and a solution by using 802.11 parameters (TXOP) is given. Validation is made in our testbed and the technique used in this paper could be applied to improve the performance of other real-time applications over 802.11-like networks. Optimisation of capacity in various 802.11 gaming scenarios
Hanghang Qi, David Malone, Dmitri Botvich
International Journal of Advanced Media and Communication, Vol. 4, No. 4 (2010) pp. 302 - 323
As IEEE 802.11 WLANs are widely deployed and the popularity of computer games continues increasing, real-time multiplayer games are increasingly played over 802.11 networks. In this paper, we consider the issues of games over 802.11 wireless networks and give a framework to study this kind of applications. A multiplayer game traffic model is produced using Quake 4 as an example. By introducing IEEE 802.11 MAC model, we show how the performance changes as the number of players increases including throughout, delay, jitter and Mean Opinion Score (MOS). Several different network scenarios then are considered. The issue of bottleneck effect at the AP is identified and a solution by using 802.11 parameters (TXOP) is given. Validation is made in our testbed and the technique used in this paper could be applied to improve the performance of other real-time applications over 802.11-like networks.

]]> 10.1504/IJAMC.2010.036833 International Journal of Advanced Media and Communication, Vol. 4, No. 4 (2010) pp. 302 - 323 Hanghang Qi David Malone Dmitri Botvich Hamilton Institute, National University of Ireland, Maynooth, Ireland. ' Hamilton Institute, National University of Ireland, Maynooth, Ireland. ' Telecommunications Software & Systems Group, Waterford Institute of Technology, Ireland IEEE 802.11 multiplayer games bottlenecks QoS TXOP multicast WLANs wireless LANs computer games gaming wireless networks traffic modelling quality of service capacity optimisation. 2010-11-11T23:20:50-05:00 4 4 302 323 2010-11-11T23:20:50-05:00 http://www.inderscience.com/link.php?id=36834 This paper proposes Bandwidth-Aware Peer Selection (BAPS), a peer selection strategy that improves the bandwidth utilisation for Peer-to-Peer (P2P) 3D streaming in a real-time Virtual Environment (VE). BAPS enhances Flowing Level-of-Details (FLoD), another P2P 3D streaming scheme, by avoiding request contention and peer overloading. We compare BAPS with FLoDs strategies that select from only peers within the Area of Interest (AOI) as data sources and do not consider peer bandwidth capacity. Our evaluation shows that BAPS achieves better performance in general, and maintains a stable minimal Quality of Service (QoS) for streaming, which is important for commercial applications. Bandwidth-aware Peer-to-Peer 3D streaming
Chien-Hao Chien, Shun-Yun Hu, Jehn-Ruey Jiang, Chuan-Wei Cheng
International Journal of Advanced Media and Communication, Vol. 4, No. 4 (2010) pp. 324 - 342
This paper proposes Bandwidth-Aware Peer Selection (BAPS), a peer selection strategy that improves the bandwidth utilisation for Peer-to-Peer (P2P) 3D streaming in a real-time Virtual Environment (VE). BAPS enhances Flowing Level-of-Details (FLoD), another P2P 3D streaming scheme, by avoiding request contention and peer overloading. We compare BAPS with FLoDs strategies that select from only peers within the Area of Interest (AOI) as data sources and do not consider peer bandwidth capacity. Our evaluation shows that BAPS achieves better performance in general, and maintains a stable minimal Quality of Service (QoS) for streaming, which is important for commercial applications.

]]> 10.1504/IJAMC.2010.036834 International Journal of Advanced Media and Communication, Vol. 4, No. 4 (2010) pp. 324 - 342 Chien-Hao Chien Shun-Yun Hu Jehn-Ruey Jiang Chuan-Wei Cheng Department of Computer Science and Information Engineering, National Central University, Taoyuan, 32001, Taiwan. ' Department of Computer Science and Information Engineering, National Central University, Taoyuan, 32001, Taiwan. ' Department of Computer Science and Information Engineering, National Central University, Taoyuan, 32001, Taiwan. ' Department of Computer Science and Information Engineering, National Central University, Taoyuan, 32001, Taiwan P2P streaming peer-to-peer VEs virtual environments 3D streaming bandwidth-aware peer selection bandwidth utilisation quality of service QoS. 2010-11-11T23:20:50-05:00 4 4 324 342 2010-11-11T23:20:50-05:00 http://www.inderscience.com/link.php?id=36835 Massively Multi-player Online Games (MMOGs) have stringent latency requirements and handle large numbers of concurrent players. To support these conflicting requirements, it is common to divide the virtual environment into virtual regions, and spawn multiple instances of isolated game areas, to serve multiple distinct groups of players. As MMOGs attract players across the world, dispersing these regions and instances on geographically distributed servers is plausible. With Ginnungagap, we present the prototype implementation and evaluation of functionality for migrating objects to support dynamic re-distribution of game-state, with a distributed name server efficiently maintaining references to migrated objects. Core-selection algorithms, using players latencies, can then locate an optimal placement for a given region or instance. The variance of the measured latencies (and core-selection algorithm) is reduced by enabling our TCP modifications for latency reduction for non-greedy streams. Correspondingly, we anticipate a decrease in aggregate latency for the affected players. Reducing game latency by migration, core-selection and TCP modifications
Paul B. Beskow, Andreas Petlund, Geir A. Erikstad, Carsten Griwodz, Pal Halvorsen
International Journal of Advanced Media and Communication, Vol. 4, No. 4 (2010) pp. 343 - 363
Massively Multi-player Online Games (MMOGs) have stringent latency requirements and handle large numbers of concurrent players. To support these conflicting requirements, it is common to divide the virtual environment into virtual regions, and spawn multiple instances of isolated game areas, to serve multiple distinct groups of players. As MMOGs attract players across the world, dispersing these regions and instances on geographically distributed servers is plausible. With Ginnungagap, we present the prototype implementation and evaluation of functionality for migrating objects to support dynamic re-distribution of game-state, with a distributed name server efficiently maintaining references to migrated objects. Core-selection algorithms, using players latencies, can then locate an optimal placement for a given region or instance. The variance of the measured latencies (and core-selection algorithm) is reduced by enabling our TCP modifications for latency reduction for non-greedy streams. Correspondingly, we anticipate a decrease in aggregate latency for the affected players.

]]> 10.1504/IJAMC.2010.036835 International Journal of Advanced Media and Communication, Vol. 4, No. 4 (2010) pp. 343 - 363 Paul B. Beskow Andreas Petlund Geir A. Erikstad Carsten Griwodz Pal Halvorsen Simula Research Laboratory, N-1325 Lysaker, Norway; Department of Informatics, Univ. Oslo, N-0316 Oslo, Norway. ' Simula Research Laboratory, N-1325 Lysaker, Norway; Department of Informatics, Univ. Oslo, N-0316 Oslo, Norway. ' Simula Research Laboratory, N-1325 Lysaker, Norway; Department of Informatics, Univ. Oslo, N-0316 Oslo, Norway. ' Simula Research Laboratory, N-1325 Lysaker, Norway; Department of Informatics, Univ. Oslo, N-0316 Oslo, Norway. ' Simula Research Laboratory, N-1325 Lysaker, Norway; Department of Informatics, Univ. Oslo, N-0316 Oslo, Norway latency reduction massively multi-player online games MMOGs TCP enhancements core selection algorithms object migration distributed name servers game latency gaming computer games. 2010-11-11T23:20:50-05:00 4 4 343 363 2010-11-11T23:20:50-05:00 http://www.inderscience.com/link.php?id=36836 To serve millions of players, Massively Multiplayer Online Game (MMOG) operators pre-provision and then maintain thousands of computer resources. We investigate a hybrid resource provisioning model that uses smaller and cheaper data centers, complemented during peak hours by virtualised cloud computing resources. Through trace-based simulation and empirical experimentation, we assess the impact of provisioning virtualised cloud resources, analyse the virtualisation overhead, and compare provisioning of virtualised resources with resource ownership. Using a simple cost model, we also investigate the costs of hosting MMOGs on the resources leased independently from three commercial cloud providers, including Amazon. The impact of virtualisation on the performance and operational costs of Massively Multiplayer Online Games
Alexandru Iosup, Vlad Nae, Radu Prodan
International Journal of Advanced Media and Communication, Vol. 4, No. 4 (2010) pp. 364 - 386
To serve millions of players, Massively Multiplayer Online Game (MMOG) operators pre-provision and then maintain thousands of computer resources. We investigate a hybrid resource provisioning model that uses smaller and cheaper data centers, complemented during peak hours by virtualised cloud computing resources. Through trace-based simulation and empirical experimentation, we assess the impact of provisioning virtualised cloud resources, analyse the virtualisation overhead, and compare provisioning of virtualised resources with resource ownership. Using a simple cost model, we also investigate the costs of hosting MMOGs on the resources leased independently from three commercial cloud providers, including Amazon.

]]> 10.1504/IJAMC.2010.036836 International Journal of Advanced Media and Communication, Vol. 4, No. 4 (2010) pp. 364 - 386 Alexandru Iosup Vlad Nae Radu Prodan Parallel and Distributed Systems Group, Delft University of Technology, Mekelweg 4, 2628CD Delft, The Netherlands. ' Institute for Computer Science, University of Innsbruck, Technikerstrasse 21a, A-6020 Innsbruck, Austria. ' Institute for Computer Science, University of Innsbruck, Technikerstrasse 21a, A-6020 Innsbruck, Austria virtualisation impact MMOGs massively multiplayer online games performance operational costs resource provisioning on-demand data centres cloud computing Amazon EC2 gaming computer games. 2010-11-11T23:20:50-05:00 4 4 364 386 2010-11-11T23:20:50-05:00 http://www.inderscience.com/link.php?id=36837 Distributed Virtual Environment (DVE) topology management and message propagation schemes have been proposed for many years. Evaluating DVE message propagation schemes requires a variety of assumptions whose verity significantly affects results, such as details about avatar movement characteristics. We implemented two schemes for waypoint and hotspot detection, and examined their applicability for characterising avatar movement. We confirmed that waypoint detection does not yield good results for characterising human avatar movement, and gained new insight into why by rendering avatar movement as point clouds. We implemented an existing hotspot detection model, and proposed an enhancement to help overcome one limitation of cell-based hotspot detection. We were able to immediately apply this hotspot detection technique to help analyse group movement. We discovered that although a third of movement time in the battlegrounds is spent in inter-node journeys, less than a quarter of these journeys are made in groups. Group movement in World of Warcraft Battlegrounds
John L. Miller, Jon Crowcroft
International Journal of Advanced Media and Communication, Vol. 4, No. 4 (2010) pp. 387 - 404
Distributed Virtual Environment (DVE) topology management and message propagation schemes have been proposed for many years. Evaluating DVE message propagation schemes requires a variety of assumptions whose verity significantly affects results, such as details about avatar movement characteristics. We implemented two schemes for waypoint and hotspot detection, and examined their applicability for characterising avatar movement. We confirmed that waypoint detection does not yield good results for characterising human avatar movement, and gained new insight into why by rendering avatar movement as point clouds. We implemented an existing hotspot detection model, and proposed an enhancement to help overcome one limitation of cell-based hotspot detection. We were able to immediately apply this hotspot detection technique to help analyse group movement. We discovered that although a third of movement time in the battlegrounds is spent in inter-node journeys, less than a quarter of these journeys are made in groups.

]]> 10.1504/IJAMC.2010.036837 International Journal of Advanced Media and Communication, Vol. 4, No. 4 (2010) pp. 387 - 404 John L. Miller Jon Crowcroft Microsoft Research, Cambridge, CB3 0FB, UK; University of Cambridge Computer Laboratory, Cambridge, CB3 0FD, UK. ' University of Cambridge Computer Laboratory, Cambridge, CB3 0FD, UK avatar movements massively multiplayer online games MMOGs World of Warcraft Battlegrounds waypoint navigation hotspots avatars computer games gaming distributed virtual environments DVE message propagation waypoint detection hotspot detection group movement. 2010-11-11T23:20:50-05:00 4 4 387 404 2010-11-11T23:20:50-05:00 http://www.inderscience.com/link.php?id=36838 This paper presents an analysis of relations between player motivation and behaviour in a Massively Multiplayer Online Role-Playing Game (MMORPG). Player motivation is measured in terms of percentile ranks of motivational components for MMORPG players defined by Nick Yee. Player behaviour is described through previously defined action categories for MMORPGs (Trading, Questing, Dungeons, Raiding, Player versus Player Combat, and Communication). We conduct a player survey and perform measurements on the client side for a group of 104 players of World of Warcraft. Additionally we examine the importance of both voice and textual communication in MMORPGs. Why MMORPG players do what they do: relating motivations to action categories
Mirko Suznjevic, Maja Matijasevic
International Journal of Advanced Media and Communication, Vol. 4, No. 4 (2010) pp. 405 - 424
This paper presents an analysis of relations between player motivation and behaviour in a Massively Multiplayer Online Role-Playing Game (MMORPG). Player motivation is measured in terms of percentile ranks of motivational components for MMORPG players defined by Nick Yee. Player behaviour is described through previously defined action categories for MMORPGs (Trading, Questing, Dungeons, Raiding, Player versus Player Combat, and Communication). We conduct a player survey and perform measurements on the client side for a group of 104 players of World of Warcraft. Additionally we examine the importance of both voice and textual communication in MMORPGs.

]]> 10.1504/IJAMC.2010.036838 International Journal of Advanced Media and Communication, Vol. 4, No. 4 (2010) pp. 405 - 424 Mirko Suznjevic Maja Matijasevic Faculty of Electrical Engineering and Computing, University of Zagreb, Unska 3, HR-10000 Zagreb, Croatia. ' Faculty of Electrical Engineering and Computing, University of Zagreb, Unska 3, HR-10000 Zagreb, Croatia MMORPG massively multiplayer online role-playing games player motivation player behaviour session characterisation session patterns action categories VoIP computer games gaming World of Warcraft voice communication text communication. 2010-11-11T23:20:50-05:00 4 4 405 424 2010-11-11T23:20:50-05:00