Pervasive computing applications must be engineered to provide unprecedented levels of flexibility in order to reconfigure and adapt in response to changes in computing resources and user requirements. To meet these c...
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ISBN:
(纸本)0769522998
Pervasive computing applications must be engineered to provide unprecedented levels of flexibility in order to reconfigure and adapt in response to changes in computing resources and user requirements. To meet these challenges, appropriate software engineering abstractions and infrastructure are required as a platform on which to build adaptive applications. In this paper we demonstrate the use of a disciplined, model-based approach to engineer a context-aware, Session Initiation Protocol (SIP) based communication application. This disciplined approach builds on our previously developed conceptual models and infrastructural components, which enable the description, acquisition, management and exploitation of arbitrary types of context and user preference information to enable adaptation to context changes.
Recent years have witnessed a growing interest in the application of wireless sensor networks in unattended environments. Nodes in such applications are equipped with limited energy supply and need careful management ...
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ISBN:
(纸本)9780780387355
Recent years have witnessed a growing interest in the application of wireless sensor networks in unattended environments. Nodes in such applications are equipped with limited energy supply and need careful management in order to extend their lifetime. In order to conserve energy, many of the routing protocols proposed for wireless sensor networks reduce the number of transmitted packets by pursuing in-network data aggregation. Almost all of the aggregation schemes presented in the literature strive to save sensor's energy while considering unconstrained data traffic. However, aggregation extends the queuing delay at the relay nodes and can thus complicate the handling of latency-constrained data. In this paper, we analyze the conditions for effective aggregation of data traffic that is subject to end-to-end delay constraints. We present an algorithm for achieving maximal possible energy saving through data aggregation while meeting the desired level of timeliness. A Weighted Fair Queuing based mechanism for packet scheduling is employed at each node in order to perform service differentiation and ensure bounded delay for constrained traffic. The performance of the proposed approach is qualified via simulation.
Sentire represents a framework for building extensible middleware for sensor and actuator networks (SANET). The fundamental principle behind Sentire is the partitioning of SANET middleware into logically related compo...
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ISBN:
(纸本)0769523005
Sentire represents a framework for building extensible middleware for sensor and actuator networks (SANET). The fundamental principle behind Sentire is the partitioning of SANET middleware into logically related components in order to allow developers of different aspects of the middleware to share a common plug-in infrastructure where their developed artifacts can interact. In this paper, an extended introduction of Sentire is presented, followed by a practical illustration of how this framework can be used to build SANET middleware.
We present the design goals and functional components of MASTAQ, a data management middleware for pervasive applications that utilize sensor data. MASTAQ allows applications to specify their Quality-of Information (Qo...
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ISBN:
(纸本)0769523005
We present the design goals and functional components of MASTAQ, a data management middleware for pervasive applications that utilize sensor data. MASTAQ allows applications to specify their Quality-of Information (QoI) preferences (in terms of statistical metrics over the data) independent of the underlying network topology. It then achieves energy efficiency by adaptively activating and querying only the subset of sensor nodes needed to meet the target QoI bounds. We also present a closed-loop feedback mechanism based on broadcasting of activation probabilities, which allows MASTAQ to activate the appropriate number of sensors without requiring any inter-sensor coordination or knowledge of the actual deployment.
The main goal of research concerning energy aware routing algorithm for wireless sensor network is to increase the lifetime and long-term connectivity of the wireless sensor networks. However, most of energy aware rou...
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ISBN:
(纸本)3540281029
The main goal of research concerning energy aware routing algorithm for wireless sensor network is to increase the lifetime and long-term connectivity of the wireless sensor networks. However, most of energy aware routing algorithms do not take into account the clustering mechanism efficiently. In this paper, we present an efficient energy aware routing algorithm for the wireless sensor networks. In our algorithm, the data aggregation technique and adaptive clustering mechanism are considered for reducing and compacting the cumulative size of packets on the wireless sensor networks. Simulation results show that the energy usage of EAR-ACM is significantly reduced compared with the previous clustering based routing algorithm for the sensor networks.
In this paper we propose a new peer-to-peer protocol for atomic reliable multicast based on view consistency. It is designed for nearly real-time collaborative applications which require consistency of data in a group...
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ISBN:
(纸本)9780780387355
In this paper we propose a new peer-to-peer protocol for atomic reliable multicast based on view consistency. It is designed for nearly real-time collaborative applications which require consistency of data in a group of participants. A typical example for this is drawing on a shared whiteboard. Collaborations frequently arise in an ad-hoc way in which setting up and operating a dedicated server is not feasible. Thus. our protocol is intended to be used in server-less environments and avoids dependence on central components. We implemented our protocol using the peer-to-peer middleware JXTA for use in TCP/IP-connected networks. This implementation offers its service to other applications via a lean Java API.
In the rapidly developing field of sensor networks, bridging the gap between the applications and the hardware presents a major challenge. Although middleware is one solution, it must be specialized to the qualities o...
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ISBN:
(纸本)0769522998
In the rapidly developing field of sensor networks, bridging the gap between the applications and the hardware presents a major challenge. Although middleware is one solution, it must be specialized to the qualities of sensor networks, especially energy consumption. The work presented here provides two contributions: a new operational setting for sensor networks and a middleware for easing software development in this setting. The operational setting we target removes the usual assumption of a central collection point for sensor data. Instead the sensors are sparsely distributed in an environment, not necessarily able to communicate among themselves, and a set of clients move through space accessing the data of sensors nearby, yielding a system which naturally provides context relevant information to client applications. We further assume the clients are wirelessly networked and share locally accessed data. This scenario is relevant, for example, when relief workers access the information in their zone and share this information with other workers. Our second contribution, the middleware itself is an extension of LIME, our earlier work on middleware for mobile ad hoc networks. The model makes sensor data available through a tuple space interface, providing the illusion of shared memory between applications and sensors. This paper presents both the model and the implementation of our middleware incorporated with the Crossbow Mote sensor platform.
The emergence of Internet, Intranet, local area networks, and ad hoc wireless networks introduces a plethora of new problems in information processing. In order to overcome these problems, we combine the Grid and P2P ...
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ISBN:
(纸本)3540281029
The emergence of Internet, Intranet, local area networks, and ad hoc wireless networks introduces a plethora of new problems in information processing. In order to overcome these problems, we combine the Grid and P2P technologies, and propose a dynamic hierarchical agent-based infrastructure. By dint of agents, we can not only overcome a lot of limitations of the mechanisms which Grid and P2P support for data management and interchange in large-scale dynamic distributedsystems, but also provide a suitable paradigm for implementing systems that need to configure adaptively, and especially keep users' information local to preserve individual privacy.
Security in wireless sensor networks is currently provided exclusively through symmetric key cryptography. In this paper we show that special purpose ultra-low power hardware implementations of public key algorithms c...
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ISBN:
(纸本)0769523005
Security in wireless sensor networks is currently provided exclusively through symmetric key cryptography. In this paper we show that special purpose ultra-low power hardware implementations of public key algorithms can be used on sensor nodes. The reduced protocol overhead due to public key cryptography (PKC) translates into less packet transmissions and hence, power savings. We provide an in-depth comparison of three popular public key implementations and describe how four fundamental security services benefit from PKC.
An event correlation is becoming an important service in event-based middleware allowing subscribers in publish/subscribe paradigm to consume patterns of events (composite events). Recent evolution of wireless network...
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ISBN:
(纸本)0769523005
An event correlation is becoming an important service in event-based middleware allowing subscribers in publish/subscribe paradigm to consume patterns of events (composite events). Recent evolution of wireless networks makes events flow from tiny sensor networks to Internet scale peer-to-peer systems among event broker grids. This new paradigm requires composition of events in heterogeneous network environments, where time synchronization and network conditions vary. Most extant approaches to define event correlation lacks a formal mechanism to define complex temporal relationships among correlated events. Here, we introduce generic composite events semantics introducing interval-based semantics for event detection supporting resource-constrained environments. We precisely define complex timing constraints among correlated event instances. We discuss underlying time systems and outline real-time temporal event ordering.
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