BraunschweigWireless sensor networks for industrial process monitoring and control require highly reliable and timely data delivery. To match performance requirements specialised schedule based medium access control (MAC) protocols are employed. In order to construct an efficient system it is necessary to find a schedule that can support the given application requirements in terms of data delivery latency and reliability. Furthermore, additional requirements such as transmission power may have to be taken into account when constructing the schedule. In this paper we show how such schedule can be constructed. We describe methods and tools to collect the data necessary as input for schedule calculation. Moreover, due to the high complexity of schedule calculation, we also introduce a heuristic. We evaluate the proposed methods in a real-world process automation and control application deployed in an oil refinery and further present a long-term experiment in an office environment. Additionally, we discuss a framework for schedule life-cycle management.

Today's industrial facilities, such as oil refineries, chemical plants, and factories, rely on wired sensor systems to monitor and control the production processes. The deployment and maintenance of such cabled systems is expensive and inflexible. It is, therefore, desirable to replace or augment these systems using wireless technology, which requires us to overcome significant technical challenges. Process automation and control applications are mission-critical and require timely and reliable data delivery, which is difficult to provide in industrial environments with harsh radio environments. In this article, we present the GINSENG system which implements performance control to allow us to use wireless sensor networks for mission-critical applications in industrial environments. GINSENG is a complete system solution that comprises on-node system software, network protocols, and back-end systems with sophisticated data processing capability. GINSENG assumes that a deployment can be carefully planned. A TDMA-based MAC protocol, tailored to the deployment environment, is employed to provide reliable and timely data delivery. Performance debugging components are used to unintrusively monitor the system performance and identify problems as they occur. The article reports on a real-world deployment of GINSENG in an especially challenging environment of an operational oil refinery in Sines, Portugal. We provide experimental results from this deployment and share the experiences gained. These results demonstate the use of GINSENG for sensing and actuation and allow an assessment of its ability to operate within the required performance bounds. We also identify shortcomings that manifested during the evaluation phase, thus giving a useful perspective on the challenges that have to be overcome in these harsh application settings.

Measuring environmental data in city areas has become an important issue for municipalities due to several climate directives. As fixed measuring stations are inflexible, cost‐intensive, and limited to monitoring a specific spot, we developed a distributed environmental monitoring network called Environmental Monitoring in Metropolitan Areas (EMMA). This architecture is based on the delay tolerant networking approach and can be integrated into existing Public Transportation Networks (PTNs). Buses or other vehicles can be equipped with sensor nodes that gather data and forward messages. In order to evaluate the basic ideas of this project we performed a series of real‐world experiments. Besides analyzing the behavior of 802.11‐based Wireless Local Area Network (WLAN) between moving vehicles in a controlled environment, we also evaluated the communication performance in urban environments. Moreover, we examined the qualification of a Disruption Tolerant Networking (DTN) implementation for spreading measurement results throughout the network. The suitability of EMMA's architecture has been successfully demonstrated by these experiments. Copyright © 2007 John Wiley & Sons, Ltd.

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