Zero-programming Sensor Network Deployment

The availability of cheap and smart wireless sensing devices provides unprecedented possibilities to monitor the physical world. On the technical side these devices introduce several original research problems, many of them related to the integration of the rampant technology proposals. Global Sensor Networks (GSN) is a platform which provides a scalable infrastructure for integrating heterogeneous sensor network technologies using a small set of powerful abstractions. GSN supports the integration and discovery of sensor networks and sensor data, provides distributed querying, filtering, and combination of sensor data, and offers dynamic adaption of the system configuration during operation through a declarative XML-based language, and enables zero-programming deployment and management. 1. Towards a Sensor Internet In 1999, Business Week named networked micro-sensor technology as one of the 21 most important technologies of the century. To date, the research in the sensor network community has mainly focused on routing protocols and information collection and aggregation in a single sensor network with multiple different sensors connected through wireless links. As the prices of sensors decrease rapidly, there will soon exist huge numbers of sensor networks in different places, managed by different organizations. To fully exploit the potential of this “Sensor Internet,” platforms enabling the fast and easy deployment, integration and management of the sensor sites and the produced data streams will be required. At the moment these issues are mostly addressed in an ad-hoc fashion. Given the current growth rate, we may soon expect to arrive at a situation comparable to the publication of documents on the Web whose success is mainly based on sharing a few simple logical abstractions (URL, hyperlink, HTML) and basic communication protocols (HTTP, more recently Web Services) that provide universal access and linking The work presented in this paper was supported (in part) by the National Competence Center in Research on Mobile Information and Communication Systems (NCCR-MICS), a center supported by the Swiss National Science Foundation under grant number 5005-67322 and by the L́on project supported by Science Foundation Ireland. among autonomously published data sources. The Global Sensor Networks (GSN) platform takes up these successful ideas and aims at making publication and access to sensor networks and sensor data as simple, powerful, and exible as accessing Web documents. The design of GSN follows four basic goals: Simplicity: The system is based on a minimal set of powerful abstractions which can be easily congured and adopted to the user’s needs. Sensor networks and data streams are dened in a declarative way using SQL as data manipulation language. XML is used as the syntactic framework for system conguration. Adaptivity: Adding new types of sensor networks and dynamic (re-)conguration of data sources is supported during run-time without having to interrupt ongoing system operation. To that end we use a container-based implementation facilitating dynamic reconguration. Scalability: By targeting a very large number of data producers and consumers with a variety of application requirements, GSN has to consider scalability issues specifically for distributed query processing and distributed discovery of sensor networks. To meet this requirement, the design of GSN is based on a peer-to-peer architecture. Light-weight implementation: GSN can be deployed in standard computing environments without excessive hardware or bandwidth requirements. It is portable, requires minimal conguration, and is easy to install and use. In this paper we provide a brief overview of GSN. We sketch a simple usage scenarios in Section 2, provide an overview of the underlying conceptual model in Section 3, discuss basic abstractions in Section 4, introduce GSN’s architecture in Section 5, and present related work in Section 6 before concluding. A detailed description of GSN is provided in [1] and the implementation is available from http://globalsn.sourceforge.net/. 2. A Simple Application Example To illustrate the potential applications and exibility of GSN we provide a simple application scenario in a (university) building as shown in Figure 1. We assume the following, fairly typical hardware setup: wireless cameras with built-in HTTP access; wireless sensors (motes) equipped with light, sound, temperature, pressure, etc. sensors (we assume that all motes of the same type form a sensor network); RFID tags which are attached to the key rings of people, and to books, mobile phones and laptops in the buildings; and several RFID readers whose coverage ranges are shown in yellow (gray) in Figure 1.