Pedro Javier del Cid

Middleware for resource sharing in multi-purpose Wireless Sensor Networks

In order to improve application reaction times and decrease overall transmission overhead, Wireless Sensor Network (WSN) applications are being developed to push intelligence into the network. In multi-purpose enterprise deployments of WSNs the infrastructure is considered a lightweight service platform that can provide services for multiple concurrent distributed applications. In this context our middleware focuses on efficiently managing shared resources while considering Quality of Data (QoD) and context aware operation. In this paper we address the issue of how concurrent use of WSN services may lead to consequential contention over a sensor nodes resources. We contribute by introducing share-able components that minimize the consequential resources needed and a resource planner that effectively reserves these resources. A prototype implementation and evaluation are provided.

DARMA: adaptable service and resource management for wireless sensor networks

This paper argues that service oriented architectures provide a good mechanism for managing outside interaction with software resources on wireless sensor networks. Specifically, this paper introduces a lightweight service platform designed to meet the specific characteristics of wireless sensor networks. The proposed architecture provides lightweight, yet flexible service-level agreements, together with adaptive management of sensor network resources. Critically for resource constrained sensor networks, our framework ensures that services are shared in an optimal manner between multiple client applications, while providing autonomic mechanisms to reason about fault tolerance and optimization. Furthermore, our approach actively promotes point of action processing which provides significant benefits in both embedded and enterprise deployments. We illustrate the appropriateness of the proposed architecture through a prototype implementation and evaluation using the LooCI component model and the SunSPOT platform.

Ensuring application integrity in shared sensing environments

Smart Environments, such as smart offices, must support multiple applications that are deployed and managed by different parties. Smart Environments are always on and application software must therefore be deployed, configured and reconfigured while the system is running. Re-configurable component models provide the basic mechanisms necessary to achieve run-time reconfiguration. However, in cases with shared component instances, ensuring application integrity during 3rd party reconfiguration leads to high developer effort and disruption. This paper addresses this problem through Composition-Swapping, an extension of re-configurable component models wherein state management delegation and extended component meta-data are used to support component-sharing and ensure application integrity. We demonstrate that Composition-Swapping reduces reconfiguration effort and disruption for four concurrently running applications on a real-world smart office environment.

Sensor Middleware to Support Diverse Data Qualities

Wireless Sensor Network (WSN) applications are traditionally developed on a per-case basis, offering very little reusability or extensibility. Any runtime variability in required data quality is at best addressed by parameterization, reconfiguration and rewiring of existing service compositions. These generic mechanisms can be further optimized if the same data is to be provided at various qualities, as is often the case in WSNs where multiple applications are interested in data from the same sensors. We propose the use of configurable components that may be concurrently used in multiple compositions and allow data quality properties to vary in each composition. Furthermore, the addition of new components or new clients does not affect existing dependencies. As a result we obtain efficient and flexible parameterization. In order to achieve this configuration mode, a patterned structure and behavior for all components is used which leads to fewer dependencies allowing for simpler reconfiguration of service compositions. A prototype implementation and an evaluation are included.

Applying a metadata level for concurrency in wireless sensor networks

Achieving a clean separation of concerns is a well known approach to improving system adaptability and evolution. We propose to apply this principle to run‐time reconfigurable component models for networked embedded systems. By separating configuration properties from runtime component instances, we achieve: (i) improved support for concurrent component use, (ii) optimized resource use, and (iii) reduced effort in runtime configuration management. We demonstrate how this approach can be seamlessly implemented on existing component models for wireless sensor networks without imposing additional constraints and without changes to their API or coordination model. Furthermore, significant memory savings are achieved in concurrent scenarios. Copyright

Resource Management Middleware to Support Self Managing Wireless Sensor Networks

In the vision of pervasive computing, technology is integrated throughout our environment. Wireless sensor networks (WSNs) provide support for pervasive computing applications through integration of environmental data. We believe that previous approaches to resource management in WSNs are designed to provide support for a specific application and do not adequately support the vision of pervasive computing. A separation of concerns between application logic and resource management is needed to provide adequate support for multiple concurrent applications using the WSN infrastructure. Additionally, sensor resource management middleware should provide appropriate primitives to support the creation of self-management frameworks. These frameworks should support the sharing of sensor network resources between multiple applications and should be extensible in order to comply with changing business needs, while leveraging on the existing infrastructure. This paper presents a component-based resource management middleware architecture that is designed to support the construction of large scale, self-managing distributed systems. We will show how the proposed architecture provides resource management support for concurrent applications while promoting reusability and extensibility for both sensor network infrastructure and software services. Furthermore our approach actively promotes point of action processing, which provides significant benefits in enterprise application deployments.

ACS: Specifying "Smart" Applications Using Sense-Process-Consume Flows

Smart applications enable pervasive and informed interactions between the physical and digital worlds. These applications are deployed on resource constrained wireless sensor networks and are commonly implemented using software modularization schemes such as components and services. Composing smart applications at the abstraction level offered by embedded software modularization schemes is complex and time consuming. The complexity of composing them is derived from the need to understand many low-level issues, e.g. embedded programming languages, coordination mechanisms, software tool chains. We present an application composition service that reduces composition effort by offering a declarative specification of sense, process and consume flows. We demonstrate reduction in composition effort for three real-world smart applications deployed on a smart office environment.

Optimizing resource use in multi-purpose WSNs

In multi-purpose Wireless Sensor Networks (WSNs) the infrastructure is considered a light-weight service platform that can provide services for multiple concurrent distributed applications. Concurrently running applications share network resources and each may have varying Quality of Data (QoD) requirements. In this context our research focuses on optimizing resource use while considering QoD and context aware operation. Specifically we address in-network distributed processing of service provider selection, autonomic service composition and reconfiguration to maximize resource use and efficiently supporting runtime variability in QoD.

Expressing and Configuring Quality of Data in Multi-purpose Wireless Sensor Networks

Wireless Sensor Networks (WSNs) are evolving towards interconnected, sensing, processing and actuating infrastructures that are expected to provide services for multiple concurrent applications. In a multi-purpose WSN, concurrently running applications share network resources and each may have varying Quality of Data (QoD) requirements. Our middleware targets these multi-purpose WSN deployments. Specifically this paper discusses how one should express and configure QoD properties for multi-purpose WSNs. We contribute by presenting our approach; which leverages per-instance QoD configuration and a separation of operational concerns to achieve simpler configuration and improve adaptability and customize-ability of the WSN. A prototype implementation and comparison to the related state of the art in WSNs are provided.