On Data Management in Pervasive Computing Environments

Abstract—This paper presents a framework to address new data management challenges introduced by data-intensive, pervasive computing environments. These challenges include a spatio-temporal variation of data and data source availability, lack of a global catalog and schema, and no guarantee of reconnection among peers due to the serendipitous nature of the environment. An important aspect of our solution is to treat devices as semiautonomous peers guided in their interactions by profiles and context. The profiles are grounded in a semantically rich language and represent information about users, devices, and data described in terms of “beliefs,” “desires, ” and “intentions. ” We present a prototype implementation of this framework over combined Bluetooth and Ad Hoc 802.11 networks and present experimental and simulation results that validate our approach and measure system performance. Index Terms—Mobile data management, pervasive computing environments, data and knowledge representation, profile-driven caching algorithm, profile driven data management, data-centric routing algorithm. æ

Collaborative Joins in a Pervasive Computing Environment

Locating and obtaining context sensitive information in a mobile environment has always been a challenge. This is especially true for pervasive computing environments where in addition to limited computing and battery resources, mobile devices cannot always rely on the help of a proxy-based wired infrastructure. Rather, a collaboratio

NeighborhoodConsistent Transaction Management for Pervasive Computing Environments

Abstract. This paper examines the problem of transaction management in pervasive computing environments and presents a new approach to address them. We represent each entity as a mobile or static semi-autonomous device. The purpose of each device is to satisfy user queries based on its local data repository and interactions with other devices currently in its vicinity. Pervasive environments, unlike traditional mobile computing paradigm, do not differentiate between clients and servers that are located in a fixed, wired infrastructure. Consequently, we model all devices as peers. These environments also relax other assumptions made by mobile computing paradigm, such as the possibility of reconnection with a given device, support from wired infrastructure, or the presence of a global schema. These fundamental characteristics of pervasive computing environments limit the use of techniques developed for transactions in a “mobile ” computing environments. We define an alternative optimistic transaction model whose main emphasis is to provide a high rate of successful transaction terminations and to maintain a neighborhood-based consistency. The model accomplishes this via the help of active witnesses and by employing an epidemic voting protocol. The advantage of our model is that it enables two or more peers to engage in a reliable and consistent transaction while in a pervasive environment without assuming that they can talk to each other via infrastructure such as base stations. The advantage of using active witnesses and an epidemic voting protocol is that transaction termination does not depend on any single point of a failure. Additionally, the use of an epidemic voting protocol does not require all involved entities to be simultaneously connected at any time and, therefore, further overcomes the dynamic nature of the environments. We present the implementation of the model and results from simulations.

SOUPA: Standard Ontology for Ubiquitous and Pervasive Applications

We describe a shared ontology called SOUPA – Standard Ontology for Ubiquitous and Pervasive Applications. SOUPA is designed to model and support pervasive computing applications. This ontology is expressed using the Web Ontology Language OWL and includes modular component vocabularies to represent intelligent agents with associated beliefs, desires, and intentions, time, space, events, user profiles, actions, and policies for security and privacy. We discuss how SOUPA can be extended and used to support the applications of CoBrA, a broker-centric agent architecture for building smart meeting rooms, and MoGATU, a peer-to-peer data management for pervasive environments. 1