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ABSTRACT: The field of pervasive computing has seen a lot of exciting innovations in the past few years. However, there are currently no mechanisms for describing the properties and capabilities of pervasive computing environments in a formal manner. This makes it difficult to prove the correctnesss of a pervasive computing environment, i.e. to verify that the environment satisfies certain desired properties. In this paper, we propose a formal model for describing pervasive computing environments based on ambient calculus and the associated ambient logic. The model allows us to state and verify several properties of these environments such as "anywhere anyhow services", "mobility of devices and applications" and "context-aware adaptation ". The model allows us to describe the resources present in an environment, the operations that can be performed in the environment, and how users can use the resources in th environment to perform different kinds of activities. As a case study, we shall describe some of the resources and operations supported by the Gaia middleware using this model, and verify an example property of a pervasive computing environment supported by Gaia.
Pervasive Computing and Communications, 2008. PerCom 2008. Sixth Annual IEEE International Conference on; 04/2008
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ABSTRACT: Pervasive computing environments feature massively distributed systems containing a large number of devices, services and applications that help end-users perform various kinds of tasks. However, these systems are very complex to configure and manage. They are highly dynamic and fault-prone. Another challenge is that since these environments are rich in devices and services, they offer different ways of performing the same task; hence, it is sometimes difficult to choose the "best" resources and strategies to use at any point of time. In this paper, we describe a framework that allows the development of autonomic programs for pervasive computing environments in the form of high-level, parameterized tasks. Each task is associated with various parameters, the values of which may be either provided by the end-user or automatically inferred by the framework based on the current state of the environment, context-sensitive policies, and learned user preferences. A novel multidimensional utility function that uses both quantifiable and non-quantifiable metrics is used to pick the optimal way of executing the task. This framework allows these environments to be self-configuring, self-repairing and adaptive, and to require minimal user intervention. We have developed and used a prototype task execution framework within our pervasive computing system, Gaia (Roman et al., 2002)
Autonomic Computing, 2005. ICAC 2005. Proceedings. Second International Conference on; 07/2005
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ABSTRACT: Pervasive computing allows the coupling of the physical world to the information world, and provides a wealth of ubiquitous services and applications that allow users, machines, data, applications, and physical spaces to interact seamlessly with one another. In this paper, we propose a benchmark for evaluating pervasive computing environments. These proposed metrics facilitate the assessment and evaluation of different aspects of pervasive computing and its support for a wide variety of tasks.
Pervasive Computing and Communications Workshops, 2005. PerCom 2005 Workshops. Third IEEE International Conference on; 04/2005
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ABSTRACT: Ubiquitous computing is revolutionizing the way applications, users, resources, and physical spaces interact. Securing cyber infrastructures for ubiquitous computing environments, such as smart buildings and campuses, can be challenging. A critical cyber infrastructure is necessary that can combine networks, processors, and devices with mechanisms, protocols, and services to offer reliable, fault-tolerant, available, and secure operations. Existing CCI implementations create statically configured, confined networked subsystems that are isolated from the public Internet and are context insensitive. This leads to multiple, incompatible subsystems incapable of interoperating, thus making operations, management, and trust difficult. The Heterogeneous Survivable Trusted Information-Assurance Architecture addresses the problem of securing critical information services in large-scale ubiquitous computing environments. Hestia is a programmable middleware solution implemented as a network of middleboxes. These middleboxes form protective layers that isolate CCI services and mediate authorized access to Hestias services. They also provide a programmable, distributed, object-oriented framework that enables the integration of security, privacy, and reliability mechanisms in service-access interfaces and implementations.
IEEE Distributed Systems Online 10/2004; 5(9):1- 1.
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ABSTRACT: Ubiquitous computing envisions an environment where physical and digital devices are seamlessly integrated. Users can access their applications and data anywhere in the environment. Applications are not bound to any single device and can migrate with the user to different environments. Therefore, application mobility is an important aspect of ubiquitous computing. We consider the problem of migrating applications across different ubiquitous computing environments (i.e. across different rooms, buildings or even cities). Migration is a tough problem because different environments have different resources (devices or services) available. The context of the environments may be different as well. Hence, mobile applications must adapt to changing contexts and resource availabilities as they migrate from one environment to the next. We introduce the notion of polymorphic applications, where applications can change their structure in order to adapt to different environments. While the structure of polymorphic applications can change during migration, the functionality and the state of the application are preserved as far as possible. This enables users to perform the same tasks as they move from one environment to the next, seamlessly. We make use of ontologies to ensure that the initial and final structures of a migrating application are semantically similar in terms of functionality and behavior. This paper describes our framework for enabling mobile polymorphic applications.
Mobile and Ubiquitous Systems: Networking and Services, 2004. MOBIQUITOUS 2004. The First Annual International Conference on; 09/2004
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ABSTRACT: Pervasive computing environments augment physical spaces with a large number of devices and services that help users perform different kinds of tasks. Users in these environments interact with one or more Web services using various devices to achieve their goals. One of the problems in these environments is discovering and coordinating different Web services for achieving the user's goals. Users may not be aware of which services and devices are available in an unfamiliar environment and how to interact with them in order to achieve their goals. In order to simplify a user's interaction with the environment, we present a novel approach of modeling and managing a user's interaction with the environment based on workflows. We have built a prototype, using the popular business workflow language (BPEL) that models various processes in pervasive environments as workflows. We found that this approach improves the usability of these environments. It also increases flexibility in changing the model of interaction without having to touch individual services and applications. This approach is particularly useful in helping visitors in public spaces like malls, museums, supermarkets and hospitals.
Web Services, 2004. Proceedings. IEEE International Conference on; 08/2004
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ABSTRACT: Pervasive computing envisions a world with users interacting naturally with device-rich environments to perform various kinds of tasks. These environments must, thus, be self-managing and autonomic systems, receiving only high-level guidance from users. However, these environments are also highly dynamic $the context and resources available in these environments can change rapidly. They are also prone to failures - one or more entities can fail due to variety of reasons. The dynamic and fault-prone nature of these environments poses major challenges to their autonomic operation. In this paper we present a paradigm for the operation of pervasive computing environments that is based on goal specification and STRIPS-based planning. Users as well as application developers can describe tasks to be performed in terms of abstract goals and a planning framework decides how these goals are to be achieved. This paradigm helps improve the fault-tolerance, adaptability, ease of programming and usability of these environments. We have developed and used a prototype planning system within our pervasive computing system, Gaia.
Autonomic Computing, 2004. Proceedings. International Conference on; 06/2004
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ABSTRACT: Context-aware systems can't always identify the current context precisely, so they need support for handling uncertainty. A prototype pervasive computing infrastructure, Gaia, allows applications and services to reason about uncertainty using mechanisms such as probabilistic logic, fuzzy logic, and Bayesian networks.
IEEE Pervasive Computing 05/2004; 3(2):62- 70. · 1.55 Impact Factor
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ABSTRACT: Enabling people-to-people interaction across heterogeneous communication end-points enhances user experience and fosters people collaboration. This paper presents the design and implementation of a unified communication system, dubbed Mercury, that allows a user to interact with others using the most convenient device at the time. Mercury supports both two-way conversation and one-way messaging. It leverages the Session Initiation Protocol to manage communication sessions and exploits dynamic user context to proactively route and migrate calls. It allows for subscription to other users' unified reachability status and provides a soft ring feature via universal notification. Mercury has an extensible architecture that allows new device types to be easily incorporated into the system. Our prototype implementation integrates a variety of devices: telephones, Sametime instant messaging clients, email, and pagers.
Mobile Data Management, 2004. Proceedings. 2004 IEEE International Conference on; 02/2004
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ABSTRACT: This paper proposes a component-based programming approach to discovery. In this approach, individual discovery protocols, access models and authentication mechanisms are represented as software components called handlers. Handlers are registered with and coordinated by a software framework called a discovery agent. Configured with a battery of handlers, a discovery agent answers query and advertisement requests on behalf of mobile and other applications and applies authentication and access control policies. Based on its set of handlers, a diversity of request types and formats can be routed, translated, and fulfilled by a discovery agent. Discovery agents can easily be reconfigured, adapted, and extended as new underlying discovery protocols or client request types must be supported. A discovery agent can operate as a Web service, and can be deployed by an enterprise to service discovery requests on behalf of visiting clients. A discovery agent can also operate as a trusted co-module running on a device, and is useful for supporting mobile applications which move among environments and must accommodate a diversity of local discovery protocols.
Mobile Data Management, 2004. Proceedings. 2004 IEEE International Conference on; 02/2004
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ABSTRACT: Describes the Mercury system, whereby a user of an electronic message service receives messages on a device and in a format appropriate to his context (travelling, in a meeting, etc.); and ConChat, whereby besides transmitting his message he automatically transmits contextual information such as his location, the number and identities of other people in the room, the room's ambient temperature, lighting, and sound, other applications and devices running in the room, his mood, his personal status (on the 'phone, out to lunch, etc), and any activity in the room.
Computer 05/2003; · 1.47 Impact Factor
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ABSTRACT: Ubiquitous computing has fueled the idea of constructing sentient, information-rich "smart spaces" that extend the boundaries of traditional computing to encompass physical spaces, embedded devices, sensors, and other machinery. To achieve this, smart spaces need to capture situational information so that they can detect changes in context and adapt themselves accordingly. However, without considering basic security issues ubiquitous computing environments could be rife with vulnerabilities. Ubiquitous computing environments impose new requirements on security. Security services, like authentication and access control, have to be non-intrusive, intelligent, and able to adapt to the rapidly changing contexts of the spaces. We present a ubiquitous security mechanism that integrates context-awareness with automated reasoning to perform authentication and access control in ubiquitous computing environments.
Pervasive Computing and Communications, 2003. (PerCom 2003). Proceedings of the First IEEE International Conference on; 04/2003
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ABSTRACT: The paper discusses the Gaia metaoperating system which extends the reach of traditional operating systems to manage ubiquitous computing habitats and living spaces as integrated programmable environments. Gaia exports services to query, access, and use existing resources and context, and provides a framework to develop user-centric, resource-aware, multidevice, context-sensitive, and mobile applications.
IEEE Pervasive Computing 11/2002; 1(4):74- 83. · 1.55 Impact Factor
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ABSTRACT: ConChat is a context-aware chat program that enriches electronic communication by providing contextual information and resolving potential semantic conflicts between users.ConChat uses contextual information to improve electronic communication. Using contextual cues, users can infer during a conversation what the other person is doing and what is happening in his or her immediate surroundings. For example, if a user learns that the other person is talking with somebody else or is involved in some urgent activity, he or she knows to expect a slower response. Conversely, if the user learns that the other person is sitting in a meeting directly related to the conversation, he or she then knows to respond more quickly. Also, by informing users about the other person's context and tagging potentially ambiguous chat messages, ConChat explores how context can improve electronic communication by reducing semantic conflicts.
IEEE Pervasive Computing 02/2002; 1(3):51- 57. · 1.55 Impact Factor
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ABSTRACT: The proliferation of smart gadgets, appliances, mobile devices, PDAs and sensors has enabled the construction of ubiquitous computing environments, transforming regular physical spaces into "Active Information Spaces" augmented with intelligence and enhanced with services. This new exciting computing paradigm promises to revolutionize the way we interact with computers, services, and the surrounding physical spaces, yielding higher productivity and more seamless interaction between users and computing services. However, the deployment of this computing paradigm in real-life is hindered by poor security, particularly, the lack of proper authentication and access control techniques and privacy preserving protocols. We propose an authentication framework that addresses this problem through the use of different wearable and embedded devices. These devices authenticate entities with varied levels of confidence, in a transparent, convenient, and private manner, allowing the framework to blend nicely into ubiquitous computing environments.
Distributed Computing Systems Workshops, 2002. Proceedings. 22nd International Conference on; 02/2002
