Christos Efstratiou, A. Friday, N. Davies, K. Cheverst
{"title":"A platform supporting coordinated adaptation in mobile systems","authors":"Christos Efstratiou, A. Friday, N. Davies, K. Cheverst","doi":"10.1109/MCSA.2002.1017492","DOIUrl":"https://doi.org/10.1109/MCSA.2002.1017492","url":null,"abstract":"Mobile environments are highly dynamic, characterised by frequent and sudden changes in resource availability. As a consequence, adaptive mobile applications need to be capable of adapting their behaviour to ensure they continue to offer the best possible level of service to the user. Our experience of developing such applications has led us to believe that existing mobile middleware platforms fail to consider adaptive applications on a host as an ensemble of entities competing for the same resources; instead, focusing on the requirements of each application in isolation. A new approach is required which offers the mechanisms to support coordination of the adaptive behaviour of multiple applications in order to achieve a common goal. We present a platform designed to meet this objective. Our platform is based on the notion of the definition of system-wide flexible adaptation policies written using a form of Kowalsky's (1992) event calculus, that may be adapted according to user needs. Moreover, we also believe that by using our approach it will soon be possible to identify and resolve conflicts caused by the need to adapt to multiple contextual triggers.","PeriodicalId":419864,"journal":{"name":"Proceedings Fourth IEEE Workshop on Mobile Computing Systems and Applications","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132415023","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}
Yuri Dotsenko, E. D. Lara, D. Wallach, W. Zwaenepoel
{"title":"Extensible adaptation via constraint solving","authors":"Yuri Dotsenko, E. D. Lara, D. Wallach, W. Zwaenepoel","doi":"10.1109/MCSA.2002.1017491","DOIUrl":"https://doi.org/10.1109/MCSA.2002.1017491","url":null,"abstract":"Presents the design, implementation, and evaluation of a simple programming language for expressing scheduling policies for transmission of multiple objects across a shared network connection. A key design component of our language is the ability to express constraints among the objects to be transmitted. A policy can make ordering constraints such as \"all text objects are transmitted before any image objects\" or a policy might express rules on the the relative bandwidth allocations across objects of different types or it can reserve certain amount of bandwidth for an object. Because it is possible to express contradictory constraints, our system finds suitable approximate solutions when no precise solution is available.","PeriodicalId":419864,"journal":{"name":"Proceedings Fourth IEEE Workshop on Mobile Computing Systems and Applications","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117248777","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":"The Event Heap: a coordination infrastructure for interactive workspaces","authors":"Brad Johanson, A. Fox","doi":"10.1109/MCSA.2002.1017488","DOIUrl":"https://doi.org/10.1109/MCSA.2002.1017488","url":null,"abstract":"Coordinating the interactions of applications running on the diversity of both mobile and embedded devices that will be common in ubiquitous computing environments is still a difficult and not completely solved problem. We look at one such environment, an interactive workspace, where groups come together to collaborate on solving problems. Such a space will contain a heterogeneous collection of both new and legacy applications and devices. We propose the Event Heap, a coordination model most similar to tuplespaces, as being appropriate for such environments. We also present a prototype implementation of the Event Heap, and show that the system has performed well in actual use over the last two years in our prototype interactive workspace, the iRoom.","PeriodicalId":419864,"journal":{"name":"Proceedings Fourth IEEE Workshop on Mobile Computing Systems and Applications","volume":"36 6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117224888","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":"Context authentication using constrained channels","authors":"T. Kindberg, Kan Zhang, N. Shankar","doi":"10.1109/MCSA.2002.1017481","DOIUrl":"https://doi.org/10.1109/MCSA.2002.1017481","url":null,"abstract":"This paper presents practical protocols for authenticating the parameters that characterise a principal's context. Context features in what are known as mobile, ubiquitous, pervasive and nomadic computing systems. Location, in particular, is a highly significant contextual parameter. We present a model of context authentication based on the characteristics of communication channels. Then we present protocols for location authentication that are based on physical channel characteristics, including a protocol that we have implemented over HTTP for use from any Web browser. We conclude with a summary and discussion of the work.","PeriodicalId":419864,"journal":{"name":"Proceedings Fourth IEEE Workshop on Mobile Computing Systems and Applications","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121345841","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}