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Several recent sensor platforms combine long-range and more classical short-range radio technologies. In this poster we propose some modifications to the RPL routing protocol such that it automatically selects the most suitable radio link when more than one is available. The solution has been implemented in the ContikiOS and tested on the Zolertia Re-mote platform.

When a commercial Wireless Sensor Network designed for environmental control and security in buildings was tested before being launched, disappointing differences between the behaviour in simulations and in the real world were observed. Fortunately, these differences disappeared when the energy saving radio duty cycling protocols were deactivated. The company then decided to provide their customers with larger batteries. They also suggested the authors of this paper to start an in depth experimental analysis of radio duty cycling as implemented in the Contiki operating system for Zolertia Z1 motes. Many subtle issues that remained hidden in simulations appeared to have infrequent but disruptive consequences in the real world. These issues have been identified, understood and corrected. They were a source of inspiration for recommendations tending to improve the overall reliability of Contiki.

The RPL routing protocol and ContikiMAC are respectively two of the most popular routing and Radio Duty Cycling protocols for Wireless Sensor Networks. However, their interactions have not yet been completely understood. In this paper we explore the influence that an often neglected parameter of ContikiMAC (the CCA threshold) has on the performance of a RPL network. Different real-world experiments are presented in this study, proving that the correct parameter tuning is essential in order to have an efficient network. Based on our experience, we provide preliminary guidelines for deploying a functional WSN using these protocols in an interference-poor environment.

The vast majority of permanent sensor and actuator nodes within a building automation environment are connected to mains electricity and seldom require significant bandwidth. Therefore, it is a good choice to set up a Narrowband Power Line Communication (NB-PLC) network over the electrical cabling as an alternative to dedicated wiring or using wireless communication on the often saturated ISM radio bands. The NB-PLC technology has many similarities with Wireless Sensor and Actuator Networks (WSAN), allowing reuse of several protocols and implementations. In this paper we present an open-source NB-PLC system based on Contiki, a popular IoT operating system focused on WSANs. This solution is aimed primarily at building automation purposes such as smart lighting, but is applicable to a variety of lightweight smart systems connected to mains electricity.

We discuss whether sound can add value to people's tasting experiences. The results presented here may be a source of inspiration for experience designers in the food industry wanting to add value to food/beverage products and/or to enhance multisensory tasting events. The available new technologies allow people to use sound as an input for moments associated with our eating and drinking habits. Here, we review three studies that used chocolate as taste stimulus. In general, the results revealed that sound can, in some cases and in different ways, modulate the taste/flavor of food (i.e., sweetness, bitterness, creaminess). These results also suggest that popular songs and soundscapes can add significant hedonic value while tasting. We discuss our results in light of new technologies (e.g., virtual reality), which offer both companies and consumers potential means for bringing customized multisensory eating and drinking experiences. We also discuss how this knowledge could be further applied - and perhaps improved - in order to make these experiences more scalable and applicable for the general public.

To guarantee that a Wireless Sensor Network succeeds in delivering its expected QoS, it is essential to understand and optimize cross-layer interactions. This paper presents a study on the interactions between the RPL routing protocol and Radio Duty Cycling (RDC) protocols. This study constitutes a first step towards a full understanding of their impact on the QoS of the network. By means of simulation and real world measurements, differences in the performance of RPL with different RDC protocols were observed and explained, and several properties of the RDC protocols impairing the performance of RPL were discovered.

The Principal Component Aggregation has recently been proposed as a versatile distributed information extraction technique for sensor networks [3]. This demonstration illustrates its use for a network-level pattern recognition task. Four different patterns, or events, may be sensed by light measurements of a network of 27 nodes. The sens measurements are fused on the fly along a routing tree up to the base station, where the monitored pattern is recognized by a prediction algorithm.