Amir Yahyavi

Peer-to-peer architectures for massively multiplayer online games: A Survey

Scalability, fast response time, and low cost are of utmost importance in designing a successful massively multiplayer online game. The underlying architecture plays an important role in meeting these conditions. Peer-to-peer architectures, due to their distributed and collaborative nature, have low infrastructure costs and can achieve high scalability. They can also achieve fast response times by creating direct connections between players. However, these architectures face many challenges. Distributing a game among peers makes maintaining control over the game more complex. Peer-to-peer architectures also tend to be vulnerable to churn and cheating. Moreover, different genres of games have different requirements that should be met by the underlying architecture, rendering the task of designing a general-purpose architecture harder. Many peer-to-peer gaming solutions have been proposed that utilize a range of techniques while using somewhat different and confusing terminologies. This article presents a comprehensive overview of current peer-to-peer solutions for massively multiplayer games using a uniform terminology.

Watchmen: Scalable Cheat-Resistant Support for Distributed Multi-player Online Games

Multi-player online games are inherently distributed applications, and a wide range of distributed architectures have been proposed. However, only few successful commercial systems follow such approaches, even given their benefits, due to one main hurdle: the easiness with which cheaters can disrupt the game state computation and dissemination, perform illegal actions, or unduly gain access to sensitive information. The challenge is that any measures used to address cheating must meet the heavy scalability and tight latency requirements of fast paced games. We propose Watchmen, the first distributed scalable protocol designed with cheat detection and prevention in mind that supports fast paced games. It is based on a randomized dynamic proxy scheme for both the dissemination and verification of actions. Furthermore, Watchmen reduces the information exposed to players close to the minimum required to render the game. We build our proof-of-concept prototype on top of Quake III. We show that Watchmen, while scaling to hundreds of players and meeting the tight latency requirements of first person shooter games, is able to significantly reduce opportunities to cheat, even in the presence of collusion.

DyKCo: Dynamic k-coverage in wireless sensor networks

In Wireless Sensor Networks maintaining complete coverage over an area is one of the fundamental problems. The network must be able to provide the requested coverage while maximizing the network lifetime through scheduling sleep for extraneous nodes. The network should also be able to configure itself to provide different levels of coverage for different applications. In this paper we present DyKCo, a probabilistic method to provide dynamic k-coverage on the area of an event. Our proposed method creates 1-coverage on the whole sensing area and creates k-coverage on the area of a detected event. Our simulations show that we can achieve very high energy savings and high coverage which result in longer network lifetime and higher accuracy. Due to probabilistic nature of our approach it needs much less communication than similar methods to provide k-coverage.

Towards the design of a human-like FPS NPC using pheromone maps

Non-player characters (NPCs) in video games tend to be easily recognized by human players, reducing the sense of immersion and limiting the complexity of character interactions. In this paper we study various aspects of the NPCs performance and how it differs from human players. We provide categorization and metrics for quantifying some aspects of the NPCs performance and provide an in-depth analysis of the behavior of NPCs. We detail how movements, interactions, use of items, and relying on static decision-making schemes result in markedly different behaviors from humans in the popular FPS Quake III. In addition, we propose a framework relying on a special kind of influence map, a pheromone map, which can lead to a more adaptive human-like behavior. These maps can efficiently give a summary of the events in the game world, be adaptive in nature, and be effectively used in the decision making process of NPCs.