{"title":"Metrics for detection of QoS degradation over wireless LAN","authors":"T. Matsukawa, Takashi Satake, J. Yamada","doi":"10.1109/SAINT.2005.40","DOIUrl":"https://doi.org/10.1109/SAINT.2005.40","url":null,"abstract":"IEEE802.11 wireless LAN systems are being widely used and multiple wireless LAN coexistence systems like 802.11b/g are available at the same time. However, in such environments, network performance is likely to degrade because the CAMA/CA mechanism does not always work well. Especially in the 802.11b/g systems, issues on performance degradation caused by the CTS-protection mechanism come to surface. To manage and maintain the QoS in such environments, it is required to detect and estimate the QoS degradation effectively. We found that the so-called retry ratio (i.e., the retry ratio of the numbers of transmitted packets to retransmitted ones) is strongly correlated with IP-packet quality metrics through our IP packet experiments. It is thus considered that retry ratio is applicable to managing the quality of some applications over wireless LAN.","PeriodicalId":169669,"journal":{"name":"The 2005 Symposium on Applications and the Internet","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129430260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Surányi, H. Abe, Toshio Hirotsu, Yasushi Shinjo, Kazuhiko Kato
{"title":"General virtual hosting via lightweight user-level visualization","authors":"P. Surányi, H. Abe, Toshio Hirotsu, Yasushi Shinjo, Kazuhiko Kato","doi":"10.1109/SAINT.2005.32","DOIUrl":"https://doi.org/10.1109/SAINT.2005.32","url":null,"abstract":"The abundance of computing resources in current systems makes it technically feasible to run services for multiple Internet sites on a single machine. However, in the UNIX security model, a vast majority of services must be run with superuser privileges. This increases security risks considerably when numerous services are running in parallel, making the isolation of services a critical issue. Virtual hosting systems have been implemented at the application level and at the operating system (OS) level and by running services in isolated full-scale virtual machines. We present a middleware approach to general virtual hosting that does not require modifications to the OS or the application. While completely implementable in the user-level in UNIX-like OSes, our system allows secure deployment of services, even when they are executed with superuser privileges.","PeriodicalId":169669,"journal":{"name":"The 2005 Symposium on Applications and the Internet","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114901132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Implementation and evaluation of on-demand address allocation for event-driven sensor network","authors":"S. Motegi, K. Yoshihara, H. Horiuchi","doi":"10.1109/SAINT.2005.35","DOIUrl":"https://doi.org/10.1109/SAINT.2005.35","url":null,"abstract":"In this paper, we propose an energy-efficient address allocation method for the event-driven sensor network, and implement and evaluate the proposed method. The proposed method allocates a temporary address only to a sensor node which detects an event, on an on-demand basis. By performing simulation studies, we evaluated the proposed method and compared it with one of the existing methods from the perspective of the number of control messages for the address allocation. The results show that the number of control messages of the proposed method is small compared to that of the existing methods. We also evaluated the processing time overhead of the proposed method using the implemented system. Although the proposed method has little extra overhead, the results show the processing time is short enough for practical use.","PeriodicalId":169669,"journal":{"name":"The 2005 Symposium on Applications and the Internet","volume":"193 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125856983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}