Pub Date : 1994-01-01DOI: 10.1109/MCSA.1994.513481
G. Voelker, B. Bershad
Mobisaic is a World Wide Web information system designed to serve users in a mobile wireless computing environment. Mobisaic extends the Web by allowing documents to both refer and react to potentially changing contextual information, such as current location in the wireless network. Mobisaic relies on client side processing of HTML documents that support two new concepts: dynamic uniform resource locators (URLs) and active documents. A dynamic URL is one whose results depend upon the state of the user's mobile context at the time it is resolved. An active document is one that automatically updates its contents in response to changes in a user's mobile context. The paper describes the design of Mobisaic, the mechanism it uses for representing a user's mobile context, and the extensions made to the syntax and function of uniform resource locators and HyperText markup language documents to support mobility.
{"title":"Mobisaic: an information system for a mobile wireless computing environment","authors":"G. Voelker, B. Bershad","doi":"10.1109/MCSA.1994.513481","DOIUrl":"https://doi.org/10.1109/MCSA.1994.513481","url":null,"abstract":"Mobisaic is a World Wide Web information system designed to serve users in a mobile wireless computing environment. Mobisaic extends the Web by allowing documents to both refer and react to potentially changing contextual information, such as current location in the wireless network. Mobisaic relies on client side processing of HTML documents that support two new concepts: dynamic uniform resource locators (URLs) and active documents. A dynamic URL is one whose results depend upon the state of the user's mobile context at the time it is resolved. An active document is one that automatically updates its contents in response to changes in a user's mobile context. The paper describes the design of Mobisaic, the mechanism it uses for representing a user's mobile context, and the extensions made to the syntax and function of uniform resource locators and HyperText markup language documents to support mobility.","PeriodicalId":88972,"journal":{"name":"Proceedings. IEEE Workshop on Mobile Computing Systems and Applications","volume":"8 1","pages":"185-190"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88807774","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}
Pub Date : 1994-01-01DOI: 10.1109/MCSA.1994.513484
N. Asokan
In a mobile computing environment, it is desirable to protect information about the movements and activities of mobile entities from onlookers. Solutions to this problem of providing anonymity have to be developed with the constraints of mobile computing environments in mind. It is argued that this issue merits investigation. A brief survey of the nature of anonymity provided in proposed or existing mobile computing environments is presented. It is argued further that achieving limited but practical anonymity using standard cryptographic techniques is feasible. Example solutions are presented.
{"title":"Anonymity in a mobile computing environment","authors":"N. Asokan","doi":"10.1109/MCSA.1994.513484","DOIUrl":"https://doi.org/10.1109/MCSA.1994.513484","url":null,"abstract":"In a mobile computing environment, it is desirable to protect information about the movements and activities of mobile entities from onlookers. Solutions to this problem of providing anonymity have to be developed with the constraints of mobile computing environments in mind. It is argued that this issue merits investigation. A brief survey of the nature of anonymity provided in proposed or existing mobile computing environments is presented. It is argued further that achieving limited but practical anonymity using standard cryptographic techniques is feasible. Example solutions are presented.","PeriodicalId":88972,"journal":{"name":"Proceedings. IEEE Workshop on Mobile Computing Systems and Applications","volume":"70 1","pages":"200-204"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76723150","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}
Pub Date : 1994-01-01DOI: 10.1109/MCSA.1994.512746
D. Huizinga, K. A. Heflinger
DOC (Disconnected Operation Cache) is a two-level client caching system designed and implemented to support connected and disconnected operation of small form-factor, battery-powered portable computers. This paper describes some design features of DOC, and our experiences with running it in the software engineering environment of AST Research. The uniqueness of the DOC project stems from the fact that it has been designed to completely support client caching and disconnected operation of currently existing portable notebook computers. The AST's local area network, consisting of several Novell servers and top-of-the-line notebooks running MS-DOS 6.2 as clients communicating via an Ethernet connection, is used to support the system and perform experiments. DOC supports "connected", "partially disconnected", and "disconnected" modes of operation. The "partially disconnected" mode has been designed to permit DOC to respond, without server involvement, to requests on certain files that are not modified frequently. Results of our experiments indicate not only considerable performance gains for "connected" and "partially disconnected" systems, but also successful operation in the disconnected mode.
{"title":"Experience with connected and disconnected operation of portable notebook computers in distributed systems","authors":"D. Huizinga, K. A. Heflinger","doi":"10.1109/MCSA.1994.512746","DOIUrl":"https://doi.org/10.1109/MCSA.1994.512746","url":null,"abstract":"DOC (Disconnected Operation Cache) is a two-level client caching system designed and implemented to support connected and disconnected operation of small form-factor, battery-powered portable computers. This paper describes some design features of DOC, and our experiences with running it in the software engineering environment of AST Research. The uniqueness of the DOC project stems from the fact that it has been designed to completely support client caching and disconnected operation of currently existing portable notebook computers. The AST's local area network, consisting of several Novell servers and top-of-the-line notebooks running MS-DOS 6.2 as clients communicating via an Ethernet connection, is used to support the system and perform experiments. DOC supports \"connected\", \"partially disconnected\", and \"disconnected\" modes of operation. The \"partially disconnected\" mode has been designed to permit DOC to respond, without server involvement, to requests on certain files that are not modified frequently. Results of our experiments indicate not only considerable performance gains for \"connected\" and \"partially disconnected\" systems, but also successful operation in the disconnected mode.","PeriodicalId":88972,"journal":{"name":"Proceedings. IEEE Workshop on Mobile Computing Systems and Applications","volume":"10 1","pages":"119-123"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84194949","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}
Pub Date : 1994-01-01DOI: 10.1109/MCSA.1994.513479
J. F. Bartlett
A number of people see personal digital assistants, PDAs, with wireless communication as the next big thing in the computer industry. However, the current PDA's obvious limitations in computational power, storage, communication bandwidth, and display size pose the questions: can you build anything, and if so, would anyone want to use it? In order to put these dreams in perspective, we decided to build a wireless interactive PDA-based client to access the World Wide Web. The paper describes our design choices and experience with W4, the Wireless World Wide Web.
{"title":"W4-the Wireless World Wide Web","authors":"J. F. Bartlett","doi":"10.1109/MCSA.1994.513479","DOIUrl":"https://doi.org/10.1109/MCSA.1994.513479","url":null,"abstract":"A number of people see personal digital assistants, PDAs, with wireless communication as the next big thing in the computer industry. However, the current PDA's obvious limitations in computational power, storage, communication bandwidth, and display size pose the questions: can you build anything, and if so, would anyone want to use it? In order to put these dreams in perspective, we decided to build a wireless interactive PDA-based client to access the World Wide Web. The paper describes our design choices and experience with W4, the Wireless World Wide Web.","PeriodicalId":88972,"journal":{"name":"Proceedings. IEEE Workshop on Mobile Computing Systems and Applications","volume":"23 92 1","pages":"176-178"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83246761","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}
Pub Date : 1994-01-01DOI: 10.1109/MCSA.1994.513474
R. Yavatkar, N. Bhagawat
Reliable transport protocols such as TCP use end-to-end flow, congestion and error control mechanisms to provide reliable delivery over an internetwork. However, the end-to-end performance of a TCP connection can suffer significant degradation in the presence of a wireless link. We are exploring alternatives for optimizing end-to-end performance of TCP connections across an internetwork consisting of both fixed and mobile networks. The central idea in our approach is to transparently split an end-to-end connection into two separate connections; one over the wireless link and other over the wired path. The connection over the wireless link may either use regular TCP or a specialized transport protocol optimized for better performance over a wireless link. Our approach does not require any changes to the existing protocol software on stationary hosts. Results of a systematic performance evaluation using both our approach and regular TCP show that our approach yields significant performance improvements.
{"title":"Improving end-to-end performance of TCP over mobile internetworks","authors":"R. Yavatkar, N. Bhagawat","doi":"10.1109/MCSA.1994.513474","DOIUrl":"https://doi.org/10.1109/MCSA.1994.513474","url":null,"abstract":"Reliable transport protocols such as TCP use end-to-end flow, congestion and error control mechanisms to provide reliable delivery over an internetwork. However, the end-to-end performance of a TCP connection can suffer significant degradation in the presence of a wireless link. We are exploring alternatives for optimizing end-to-end performance of TCP connections across an internetwork consisting of both fixed and mobile networks. The central idea in our approach is to transparently split an end-to-end connection into two separate connections; one over the wireless link and other over the wired path. The connection over the wireless link may either use regular TCP or a specialized transport protocol optimized for better performance over a wireless link. Our approach does not require any changes to the existing protocol software on stationary hosts. Results of a systematic performance evaluation using both our approach and regular TCP show that our approach yields significant performance improvements.","PeriodicalId":88972,"journal":{"name":"Proceedings. IEEE Workshop on Mobile Computing Systems and Applications","volume":"19 1","pages":"146-152"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87601747","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}
Pub Date : 1994-01-01DOI: 10.1109/MCSA.1994.512727
A. Mukherjee, D. Siewiorek
The advent of ubiquitous mobile computing has widely been regarded as the convergence of pager-like communications technology and laptop-like computational power enabling applications that span both realms of functionality. However ubiquitous mobile computing, coupled with the proliferation of microprocessor-controlled appliances and networking, creates another important new application arena: that in which mobile computers act as controllers for and interfaces to, appliances and services in the surrounding environment. This position paper explores the convergence of computation with communications and control applications, and the models of mobile computing that consequently arise. Established applications and models are positioned relative to this framework, and hitherto unexplored control-based models of mobile computation are described.
{"title":"Mobility: a medium for computation, communication, and control","authors":"A. Mukherjee, D. Siewiorek","doi":"10.1109/MCSA.1994.512727","DOIUrl":"https://doi.org/10.1109/MCSA.1994.512727","url":null,"abstract":"The advent of ubiquitous mobile computing has widely been regarded as the convergence of pager-like communications technology and laptop-like computational power enabling applications that span both realms of functionality. However ubiquitous mobile computing, coupled with the proliferation of microprocessor-controlled appliances and networking, creates another important new application arena: that in which mobile computers act as controllers for and interfaces to, appliances and services in the surrounding environment. This position paper explores the convergence of computation with communications and control applications, and the models of mobile computing that consequently arise. Established applications and models are positioned relative to this framework, and hitherto unexplored control-based models of mobile computation are described.","PeriodicalId":88972,"journal":{"name":"Proceedings. IEEE Workshop on Mobile Computing Systems and Applications","volume":"27 1","pages":"8-11"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84970964","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}
Pub Date : 1994-01-01DOI: 10.1109/MCSA.1994.512734
R. Gruber, F. Kaashoek, B. Liskov, L. Shrira
The paper discusses issues raised by providing disconnected operation in the Thor object-oriented database system. Disconnected operation in such a system poses new challenges because of the small size of objects, the richness and complexity of their interconnections, the huge number of them, and the fact that they are accessed within atomic transactions. We propose three techniques to address these challenges: (1) using the database query language for hoarding; (2) using dependent commits to tentatively commit transactions at the disconnected client; (3) using the high-level semantic of objects to avoid transaction aborts.
{"title":"Disconnected operation in the Thor object-oriented database system","authors":"R. Gruber, F. Kaashoek, B. Liskov, L. Shrira","doi":"10.1109/MCSA.1994.512734","DOIUrl":"https://doi.org/10.1109/MCSA.1994.512734","url":null,"abstract":"The paper discusses issues raised by providing disconnected operation in the Thor object-oriented database system. Disconnected operation in such a system poses new challenges because of the small size of objects, the richness and complexity of their interconnections, the huge number of them, and the fact that they are accessed within atomic transactions. We propose three techniques to address these challenges: (1) using the database query language for hoarding; (2) using dependent commits to tentatively commit transactions at the disconnected client; (3) using the high-level semantic of objects to avoid transaction aborts.","PeriodicalId":88972,"journal":{"name":"Proceedings. IEEE Workshop on Mobile Computing Systems and Applications","volume":"45 1","pages":"51-56"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86930209","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}
Pub Date : 1994-01-01DOI: 10.1109/MCSA.1994.513478
S. Alagar, S. Venkatesan
There is a growing trend in using mobile computing environments for several applications, and it is important that such mobile systems are provided with adequate support both at the systems level and at the communication level. Causal ordering is a useful property, particularly in applications that involve human interactions. We present three algorithms for causal ordering in mobile systems. The first algorithm handles the resource constraints of the mobile hosts. But the system is not easily scalable and is not graceful in hosting disconnections and connections. The second algorithm eliminates the above disadvantages at the cost of inhibiting some messages. The third algorithm is a trade-off between the first two algorithms.
{"title":"Causally ordered message delivery in mobile systems","authors":"S. Alagar, S. Venkatesan","doi":"10.1109/MCSA.1994.513478","DOIUrl":"https://doi.org/10.1109/MCSA.1994.513478","url":null,"abstract":"There is a growing trend in using mobile computing environments for several applications, and it is important that such mobile systems are provided with adequate support both at the systems level and at the communication level. Causal ordering is a useful property, particularly in applications that involve human interactions. We present three algorithms for causal ordering in mobile systems. The first algorithm handles the resource constraints of the mobile hosts. But the system is not easily scalable and is not graceful in hosting disconnections and connections. The second algorithm eliminates the above disadvantages at the cost of inhibiting some messages. The third algorithm is a trade-off between the first two algorithms.","PeriodicalId":88972,"journal":{"name":"Proceedings. IEEE Workshop on Mobile Computing Systems and Applications","volume":"1 1","pages":"169-174"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83144934","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}
Pub Date : 1994-01-01DOI: 10.1109/MCSA.1994.512736
M. Baker
MosquitoNet is a new project at Stanford University for investigating operating system and application issues in mobile and wireless computing. Our initial goals focus on providing the appearance of continuous network connectivity for mobile hosts. To achieve these goals we must first enable portable computers to move seamlessly from one communications medium to another, for example from an Ethernet connection to a wireless modem, without rebooting or restarting applications. Second, we must determine how to manage the resulting dynamic changes in network characteristics, either transparently or through a simple interface between the network and the applications. Other goals include developing power management policies for network devices and experimenting with file data consistency algorithms for networks in which disconnection may be economically desirable, but seamless network reconnection is almost always possible.
{"title":"Changing communication environments in MosquitoNet","authors":"M. Baker","doi":"10.1109/MCSA.1994.512736","DOIUrl":"https://doi.org/10.1109/MCSA.1994.512736","url":null,"abstract":"MosquitoNet is a new project at Stanford University for investigating operating system and application issues in mobile and wireless computing. Our initial goals focus on providing the appearance of continuous network connectivity for mobile hosts. To achieve these goals we must first enable portable computers to move seamlessly from one communications medium to another, for example from an Ethernet connection to a wireless modem, without rebooting or restarting applications. Second, we must determine how to manage the resulting dynamic changes in network characteristics, either transparently or through a simple interface between the network and the applications. Other goals include developing power management policies for network devices and experimenting with file data consistency algorithms for networks in which disconnection may be economically desirable, but seamless network reconnection is almost always possible.","PeriodicalId":88972,"journal":{"name":"Proceedings. IEEE Workshop on Mobile Computing Systems and Applications","volume":"11 1","pages":"64-68"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82400106","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}
Pub Date : 1994-01-01DOI: 10.1109/MCSA.1994.512738
D. Comer, V. Russo
The paper reviews the problem of routing in a wireless Internet, and discusses a plan that combines wireless network technology with high speed Asynchronous Transfer Mode (ATM) switching technology. The combination provides a wireless communication system with sufficient aggregate bandwidth to handle both data transfers and routing updates for a university sized network. More importantly, the paper details why wireless communication is a particularly difficult problem on a university campus, and describes a routing update mechanism that can scale to routing on a large campus.
{"title":"Using ATM for a campus-scale wireless Internet","authors":"D. Comer, V. Russo","doi":"10.1109/MCSA.1994.512738","DOIUrl":"https://doi.org/10.1109/MCSA.1994.512738","url":null,"abstract":"The paper reviews the problem of routing in a wireless Internet, and discusses a plan that combines wireless network technology with high speed Asynchronous Transfer Mode (ATM) switching technology. The combination provides a wireless communication system with sufficient aggregate bandwidth to handle both data transfers and routing updates for a university sized network. More importantly, the paper details why wireless communication is a particularly difficult problem on a university campus, and describes a routing update mechanism that can scale to routing on a large campus.","PeriodicalId":88972,"journal":{"name":"Proceedings. IEEE Workshop on Mobile Computing Systems and Applications","volume":"50 1","pages":"75-79"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83992528","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}
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