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Showing papers on "Mobile technology published in 1996"


Proceedings ArticleDOI
01 Nov 1996
TL;DR: This work addresses the problem of deciding when to spin down the disk of a mobile computer in order to extend battery life by using a simple and efcient algorithm based on machine learning techniques that has excellent performance in practice.
Abstract: We address the problem of deciding when to spin down the disk of a mobile computer in order to extend battery life. Since one of the most critical resources in mobile computing environments is battery life, good energy conservation methods can dramatically increase the utility of mobile systems. We use a simple and efcient algorithm based on machine learning techniques that has excellent performance in practice. Our experimental results are based on traces collected from HP C2474s disks. Using this data, the algorithm outperforms several algorithms that are theoretically optimal in under various worst-case assumptions, as well as the best xed time-out strategy. In particular, the algorithm reduces the power consumption of the disk to about half (depending on the disk's properties) of the energy consumed by a one minute xed time-out. Since the algorithm adapts to usage patterns, it uses as little as 88% of the energy consumed by the best xed time-out computed in retrospect.

232 citations


01 May 1996
TL;DR: This paper describes the design and implementation of the mobile-agent system, Agent Tcl, and the specific features that support mobile computers and disconnected operation, including network-sensing tools and a docking system that allows an agent to transparently move between mobile computers, regardless of when the computers connect to the network.
Abstract: Mobile agents are programs that can move through a network under their own control, migrating from host to host and interacting with other agents and resources on each We argue that these mobile, autonomous agents have the potential to provide a convenient, efficient and robust programming paradigm for distributed applications, particularly when partially connected computers are involved Partially connected computers include mobile computers such as laptops and personal digital assistants as well as modem-connected home computers, all of which are often disconnected from the network In this paper, we describe the design and implementation of our mobile-agent system, Agent Tcl, and the specific features that support mobile computers and disconnected operation These features include network-sensing tools and a docking system that allows an agent to transparently move between mobile computers, regardless of when the computers connect to the network

142 citations


Journal ArticleDOI
TL;DR: This paper identifies two new QoS parameters unique to the mobile environment - guarantee of seamless service and ensuring graceful degradation of service in situations where user demands exceed the network's capacity to satisfy them.

128 citations


Proceedings ArticleDOI
21 Oct 1996
TL;DR: The problem of routing and resource reservation in mobile mesh networks is described and architectural recommendations necessary for Internet protocols to operate effectively in these environments are presented.
Abstract: Mobile communications is central to many military operations and is necessary to communicate simultaneously with multiple warfighters engaged in a common task. This paper describes the problem of routing and resource reservation in mobile mesh networks and presents architectural recommendations necessary for Internet protocols to operate effectively in these environments. A "mobile mesh" network is an autonomous system of mobile routers connected by wireless links, the union of which form an arbitrary graph. The routers are free to move randomly; thus, the network's wireless topology may change rapidly and unpredictably.

120 citations


Patent
Reijo Leppänen1
29 Oct 1996
TL;DR: In this article, a software databse (SDB) connected to a mobile communication network (NSS) contains the most recent versions of the softwares of the mobile stations.
Abstract: A prior art method for upgrading a mobile station is to change at least partly software contained therein in a service shop, for example. This solution is not satisfactory to a user of a mobile station. In accordance with the invention, the mobile station (MS) is designed to that its software can be be changed at least partly. A software databse (SDB) connected to a mobile communication network (NSS) contains the most recent versions of the softwares of the mobile stations. A downloading unit (DLU) checks the softwares of the mobile stations by means of the database (SDB) and when necessary, loads the sofware into the mobile station.

114 citations


Proceedings ArticleDOI
18 Apr 1996
TL;DR: The Cyberguide project, which is building prototypes of handheld, intelligent tour guides that provide information to a tourist based on knowledge of position and orientation, is presented.
Abstract: We are interested in prototyping future computing environments. In this paper, we present the Cyberguide project, which is building prototypes of handheld, intelligent tour guides that provide information to a tourist based on knowledge of position and orientation. We will describe features of existing Cyberguide prototypes and discuss important research issues that have emerged in contextaware applications development in a mobile environment.

110 citations


01 Jan 1996
TL;DR: This paper will identify suitable applications for mobile telephone positioning, describe the prospects for this technology, and present actual measurement results derived from GSM.
Abstract: Positioning systems are a key enabling technology for Intelligent Transport Systems (ITS). This is because most advanced applications require accurate location of vehicles. Much of the work to date on positioning has focused on the Global Positioning System (GPS). However, GPS has a number of deficiencies, including the cost of a GPS receiver and degraded performance in urban areas. An alternative that could overcome these deficiencies is to accurately locate a mobile telephone, based simply on the signals emitted by the mobile communications system. This is becoming practicable with the new mobile systems, such as Global System Mobile (GSM), which operate on a much wider bandwidth than the earlier analog systems. The location of mobile telephones can be done with no additional hardware in the handset, so reducing the cost of adding a positioning capability. As well, the large number of base stations that are normally installed in an urban area promise much more robust performance than GPS. This paper will identify suitable applications for mobile telephone positioning, describe the prospects for this technology, and present actual measurement results derived from GSM.

62 citations


Book ChapterDOI
M.G. Brown1
01 Jan 1996
TL;DR: Some important mobility issues are reviewed, some of the systems requirements raised by user mobility are looked at, and some practical experiences with mobile applications at Olivetti Research Ltd. (ORL) are described.
Abstract: The availability of wireless network connections to laptop computers and PDA’s has created interest in the issues surrounding mobile computing. However, enabling users to be genuinely mobile in their work requires more than a wireless connection. Distributed system services are needed to support the locating of people, equipment and software objects, and, especially for mobile multimedia applications, network transport protocols which can adapt to a wide range of networking conditions must be developed. This paper reviews some important mobility issues, looks at some of the systems requirements raised by user mobility, and describes some practical experiences with mobile applications at Olivetti Research Ltd. (ORL).

51 citations


Proceedings ArticleDOI
24 Mar 1996
TL;DR: This report on an ongoing project to design and build the network and transport layers for mobile networking provides summaries of all the protocols the team is implementing (or have implemented) and discusses possible improvements.
Abstract: We report on an ongoing project to design and build the network and transport layers for mobile networking. The network architecture used is unique in that it separates the mobile network(s) from fixed networks and provides connectivity between the two via special gateways. These gateways provide QOS guarantees to mobile users for all their open connections. We provide summaries of all the protocols we are implementing (or have implemented) and discuss possible improvements.

48 citations


Book ChapterDOI
01 Jan 1996
TL;DR: The rapidly expanding technology of cellular communication, wireless LANs, and satellite services will make information accessible anywhere and at any time and create an entire new class of applications and, possibly, new massive markets combining personal computing and consumer electronics.
Abstract: The rapidly expanding technology of cellular communication, wireless LANs, and satellite services will make information accessible anywhere and at any time. In the near future, tens of millions of people will carry a portable palmtop or laptop computer. Smaller units, often called personal digital assistants or personal communicators, will run on AA batteries and may have only a small memory; larger ones will be powerful laptop computers with large memories and powerful processors. Regardless of size, most mobile computers will be equipped with a wireless connection to the fixed part of the network, and, perhaps, to other mobile computers. The resulting computing environment, which is often referred to as mobile or nomadic computing, no longer requires users to maintain a fixed and universally known position in the network and enables almost unrestricted mobility. Mobility and portability will create an entire new class of applications and, possibly, new massive markets combining personal computing and consumer electronics.

43 citations


Book ChapterDOI
08 Jul 1996
TL;DR: The secure programming style advocated in [40] boils down to the following style (expressed in Java for simplicity): the class Protectee is the class that should be protected, the class Protector implements a security policy and all methods of Protectee are redefined in Protector to check source of the call.
Abstract: In this paper we discuss security in mobile object systems. Mobile object systems embody a paradigm where computation may move across the network and carry out distributed activities. This paradigm has been popularized by the JAVA programming language and the work on mobile software agent. We study security problems of interaction mobile object systems taking Java as an example, identify weaknesses and propose solutions.

Book ChapterDOI
TL;DR: In this article, the authors present a protocol and proposal for the operation of dynamic resource discovery in a mobile network, which is simple, extensible, and light weight, and implemented and tested their design with stationary servers and mobile clients running mobile IP.
Abstract: The increasing complexity of modern networks prompts a need for dynamic resource discovery. Mobile clients have the additional need to rediscover the location of local area network resources each time they move to a different LAN. We present a protocol and proposal for the operation of dynamic resource discovery. Our design is simple, extensible, and light weight. We implemented and tested our design with stationary servers, and mobile clients running mobile IP.


Journal ArticleDOI
TL;DR: The DuO vehicle tracking and fleet management system is presented as an example for a mobile computing application and the technologies of GPS positioning and GSM data communication are presented as they are used within the system.

Journal ArticleDOI
TL;DR: It is hoped that the new ACTS program will further the progress in developing wireless technologies while paying progressively growing attention to the development of a strategic vision of mobile and personal communications beyond the year 2000.
Abstract: A brief summary of the main activities performed under the RACE program in the field of mobile communications is presented, In particular, the technological studies and development have been outlined, showing that work has significantly progressed with major systems performance results already available from the various testbeds developed and coordinated by the projects. In parallel, possible evolution paths from second to third generation systems have been presented, together with regulatory trends, Beyond the technological work performed under the RACE program, it is hoped that the new ACTS program will further the progress in developing wireless technologies while paying progressively growing attention to the development of a strategic vision of mobile and personal communications beyond the year 2000. Finally, a brief presentation of the ACTS program has shown that the coming years should be devoted to services validation through active user involvement in field trials. The results are expected to he of great use to potential operators, providing them the possibility of testing user acceptance of broadband mobile services. Future mobile communications systems will need to provide users with broadband capabilities and advanced services, allowing for seamless provision across fixed and mobile networks.

Book
01 Sep 1996
TL;DR: Comprehensive coverage details application development tools, all aspects of mobile computing integration; rules-of-thumb costs; specifications and features of major products; and more.
Abstract: From the Publisher: Mobile Computing provides the end-to-end know-how required to build integrated systems and enables network providers and application developers to understand each other's requirements. This complete guide to mobile information technology is aimed at professionals building solutions based on the emerging mobile technology. Comprehensive coverage details application development tools,all aspects of mobile computing integration; rules-of-thumb costs; specifications and features of major products; and more.

Patent
Christopher L. McAfee1
09 Feb 1996
TL;DR: In this paper, a wireless communication system including a paging-type system for sending messages to a mobile device is described, where a wireless link is set up between the mobile device and a communication medium capable of allowing the mobile devices to communicate with a location specified by the messages.
Abstract: A wireless communication system including a paging-type system for sending messages to a mobile device. A wireless communication link is set up between the mobile device and a communication medium capable of allowing the mobile device to communicate with a location specified by the messages. In this manner, the mobile device is able to communicate within the system.

01 Oct 1996
TL;DR: This RFC argues that mobile network tracing provides both tools to improve the understanding of wireless channels, as well as to build realistic, repeatable testbeds for mobile software and systems.
Abstract: Mobile networks are both poorly understood and difficult to experiment with. This RFC argues that mobile network tracing provides both tools to improve our understanding of wireless channels, as well as to build realistic, repeatable testbeds for mobile software and systems. The RFC is a status report on our work tracing mobile networks. Our goal is to begin discussion on a standard format for mobile network tracing as well as a testbed for mobile systems research. We present our format for collecting mobile network traces, and tools to produce from such traces analytical models of mobile network behavior.

Proceedings ArticleDOI
25 Feb 1996
TL;DR: A new Internet technology is described, Mobile IP, which provides a foundation for addressing many of the cited requirements for practical wireless access and is being applied in the development of advanced new data services for the integrated dispatch enhanced network (iDEN).
Abstract: The development of distributed computing systems, with the associated focus on the interconnecting network, and mobile computing platforms has generated much interest in mobile data network access. Wide-area wireless communication systems are particularly of interest. This paper attempts to describe some of the challenges and potential solutions to providing wireless network access for mobile computing users. We present a set of characteristics and requirements for practical wireless access, many of which are not addressed well, if at all, by current wireless data systems. The paper then describes a new Internet technology, Mobile IP, which provides a foundation for addressing many of the cited requirements. The paper concludes with a description of how this technology is being applied in the development of advanced new data services for the integrated dispatch enhanced network (iDEN).

Journal ArticleDOI
TL;DR: A novel mobile virtual-distrubuted system architecture for supporting global mobile computing and communications is described by deploying mobile-floating agents to de-couple services and resources from the underlying network and allow them to move around following their mobile users.
Abstract: This paper describes a novel mobile virtual-distributed system architecture for supporting global mobile computing and communications. The principal contribution of this paper is to innovatively apply virtual memory concepts to mobile systems by deploying mobile-floating agents to de-couple services and resources from the underlying network and allow them to move around following their mobile users. The mobile-floating agents maintain data structures associated with a mobile user. By combining the mobile-floating agent functions with a predictive mobility management algorithm and location-aware caching and prefetching, services and user data structure are pre-connected and pre-assigned at the locations to which the user is moving. Thus, the users can maintain their data structures or immediately receive service with virtually the same efficiency as at the previous location.

01 Jan 1996
TL;DR: This dissertation describes the design and implementation of Crosspoint, a new approach to support wireless mobile internet-working on a large university campus or similar environment that combines wireless local-area network technology with high-speed switching technology.
Abstract: This dissertation proposes a new approach to support wireless mobile internet-working on a large university campus or similar environment. Called Crosspoint, the approach combines wireless local-area network technology with high-speed switching technology. The combination provides a wireless communication system with sufficient aggregate bandwidth to handle massive, synchronized movements of mobile computers. Furthermore, the approach supports optimal routing to each mobile computer without requiring modification of the networking software on mobile computers, nonmobile computers, or routers in the existing Internet. This dissertation describes the design and implementation of Crosspoint. Through a prototype implementation, we have shown that the approach is feasible.

Journal ArticleDOI
01 Sep 1996
TL;DR: The architecture of an environment aiming to support mobile users and dealing with the given problems is presented.
Abstract: Today a mobile user wants to connect his portable computer: remotely to the central database at home, locally to the printer on the spot and globally to the world-wide-web. To achieve this, different connection lines are available: wireless networks for connecting out in the fields, ISDN or analogue telephone lines when residing in a hotel, Ethernet access at the customer's site. But this connectivity raises a lot of questions, about technical, security or accounting issues. This paper presents the architecture of an environment aiming to support mobile users and dealing with the given problems.

Book ChapterDOI
TL;DR: The evaluation results show that, for a large system (200 cells), this scheme can reduce the system cost by more than 87%, for even highly mobile users, compared with a fully replicated database system.
Abstract: This paper describes a mobility-aware dynamic database caching scheme for wireless mobile computing and communications. A mobile-floating agent scheme is proposed, in which caching techniques are cognizant of the mobile nature of mobile users and the location-sensitive nature of mobile systems. The mobile-floating agent maintains a second class cache in the fixed network and employs Barbara’s “invalidation reports broadcasting” cache consistency strategies to maintain a dynamic cache consistent with the first class cache in the mobile client. The “invalidation reports broadcasting” scheme is combined with knowledge of the mobility behavior of each individual mobile user and broadcasts of invalidation reports only occur within the user’s mobility area. The evaluation results show that, for a large system (200 cells), this scheme can reduce the system cost by more than 87%, for even highly mobile users, compared with a fully replicated database system.

Proceedings ArticleDOI
15 Oct 1996
TL;DR: This paper studies the agent search problem based on an open architecture proposed by Lien and is currently being implemented in the National Chengchi University.
Abstract: In a mobile computing environment that supports mobile agents, a client can send an agent to visit a sequence of servers in the network. To track the location of agents becomes a critical problem in managing a mobile agent service network. This paper studies the agent search problem based on an open architecture proposed by Lien (see Proc. of the First Workshop on Mobile Computing, Hsing-Chu, Taiwan, p.2-9, 1995) and is currently being implemented in the National Chengchi University.


Patent
11 Jun 1996
TL;DR: In this paper, the authors proposed a mobile communications network and a mobile communication method for reducing loads to be incurred to the mobile communication network which loads occur because the user changes its mobile communication terminal.
Abstract: An object of the present invention is to provide a mobile communications network and a mobile communication method for reducing loads to be incurred to the mobile communications network which loads occur because the user changes its mobile communication terminal. Mobile communication terminal numbers of mobile communication terminals (21), (22), IDs of users (31), (32) of the mobile communication terminals, and at least one address to be used by each user when the user performs a communication. The mobile communications network comprises an address/user corresponding table (13) having a table for bringing addresses to be used in each of the multiple communication methods and a user ID into corresponding relation. When a terminating request specifying an address is made, a user ID corresponding to the specified address is obtained using the address/user corresponding table. Further, a mobile communication terminal number is retrieved using a user/mobile communication terminal corresponding table (14) for bringing the user ID and the mobile communication terminal number into a corresponding relation, then a mobile location area of the mobile communication terminal corresponding to the user ID is read, and the incoming signal is terminated in the mobile communication terminal using the mobile communication terminal number and the mobile location area.

Journal ArticleDOI
TL;DR: The VLab (Virtual laboratory) provides any‐time, any‐place process support for mobile software development teams, and presents a model that focuses on the processes involved in complex systems development and learning, and research propositions to evaluate mobile any‐ time, any-place support.
Abstract: Mobile technology research focuses on supporting the individual mobile worker. Computer supported co‐operative work research has primarily focused on supporting distributed, but fixed‐site workers. Bridges both research foci by expanding to include mobile, any‐time, any‐place support. The complementary goal is to investigate better ways to prepare future team members for the new demands in the workplace. The VLab (Virtual laboratory) provides any‐time, any‐place process support for mobile software development teams. Presents a model that focuses on the processes involved in complex systems development and learning, and research propositions to evaluate mobile any‐time, any‐place support. Baseline measurements have been obtained and early results support the value of mobile group support technology.

01 Jan 1996
TL;DR: A mobile transaction manager (MTM) is introduced that is responsible for all the global transactions created by mobile hosts, which contain a portion of the distributed database.
Abstract: Improvements in cellular and satellite technology have permitted portable computers to communicate with existing distributed computing networks. Users with palm-top computers, known as mobile hosts (MHs), utilize wireless connections to communicate with wired network from a number of locations at diierent times. In this paper, we introduce a mobile computing architecture for a battleeeld environment. When data is stored on mobile hosts, the mobility issue becomes increasingly more complicated. To deal with this issue, we introduce a mobile transaction manager (MTM) that is responsible for all the global transactions created by mobile hosts, which contain a portion of the distributed database. A battleeeld is a very unique environment due to the fact that the medical units are susceptible to damage and disconnection from an attack by an enemy force. Prime Time III, which is being supported by the Medical Advanced Technology Management OOce, is the operational name for the telemedicine support for the U.S. troop deployment in Bosnia. A distributed patient-soldier database provides patient-soldier medical information in real-time. An application of the patient-soldier database is discussed with respect to transaction management in the battleeeld environment .


Journal ArticleDOI
01 May 1996
TL;DR: This work has developed an application that searches for relevant HTML documents on a set of WWW servers and shows that significant performance improvement can be achieved by moving computation closer to data: both the elapsed time and network traffic are reduced.
Abstract: New communication applications on large scale networks such as the Internet will be driven by mobile computing and information access. We have defined a network programming model called Mobile Assistant Programming (MAP) that supports the development and execution of applications for efficient information access on the WWW. Mobile assistants are high-level interpreted programs that can move between nodes, create clones and report results. Their execution is asynchronous and persistent to allow client disconnections and survival of node and data link failures. Using an implementation of MAP based on the World-Wide Web framework and the Scheme programming language, we have developed an application that searches for relevant HTML documents on a set of WWW servers. Our experience with the MAP and the WWW application shows that significant performance improvement can be achieved by moving computation closer to data: both the elapsed time and network traffic are reduced.