Massively multiplayer online role playing games (MMORPGs) have become extremely popular among network gamers. Despite their success, one of MMORPG's greatest challenges is the increasing use of game bots, that is, autoplaying game clients. The use of game bots is considered unsportsmanlike and is therefore forbidden. To keep games in order, game police, played by actual human players, often patrol game zones and question suspicious players. This practice, however, is labor-intensive and ineffective. To address this problem, we analyze the traffic generated by human players versus game bots and propose general solutions to identify game bots. Taking Ragnarok Online as our subject, we study the traffic generated by human players and game bots. We find that their traffic is distinguishable by 1) the regularity in the release time of client commands, 2) the trend and magnitude of traffic burstiness in multiple time scales, and 3) the sensitivity to different network conditions. Based on these findings, we propose four strategies and two ensemble schemes to identify bots. Finally, we discuss the robustness of the proposed methods against countermeasures of bot developers, and consider a number of possible ways to manage the increasingly serious bot problem.
For improving the service quality of the Taiwan High-Speed Rail (THSR), a dedicated mobile WiMAX network (based on IEEE 802.16e in the current stage) is planned to be deployed along the railway of THSR. The mobile WiMAX network is not only for providing Internet access over the THSR trains, but also for delivering live entertainment contents to the passengers, such as mobile TV streaming of live programs. In this paper, we show the experiences about the design, implementation and evaluation of the mobile TV streaming service for high-speed rail reception based on AL-FEC (Application-Layer FEC). The experiment results show that AL-FEC can effectively compensate the packet losses in the high-speed reception scenario if the underlying reliability control schemes in IEEE 802.16e cannot provide error free mobile TV streaming delivery.
For the sake of satisfying the requirement of different receivers and adapting the network condition, a new video coding scheme appears and is called Scalable Video Coding (SVC). Different from traditional coding scheme i.e. H.264, encoding once by using SVC encoder can generate one bitstream with different resolutions as well as frame rate, and the bitstream can be corresponded with the requirement of different receivers. In this paper, we propose two adaptive SVC layer switching algorithms for dedicated Worldwide Interoperability for Microwave Access (WiMAX) network of Taiwan High Speed Rail (THSR). The adaptive layer switching algorithms are based on network condition to adjust to delivering video data. For the first algorithm, we record the Received Signal Strength Indicator (RSSI) trace at the high speed moving environment of THSR in advance, and measure the available network bandwidth with RSSI trace. Then, Streaming Server can deliver the corresponding SVC layer data by measured network bandwidth. As to the second algorithm, Streaming Server estimates network available bandwidth from static information such as packet loss rate sent by Streaming Client. Streaming Server can select and deliver SVC layer data which are adapted to estimated network bandwidth. Our streaming system is an adaptive streaming system because video layer switching adapts to different network conditions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.