Jen Rossey

Facilitating Sensor Deployment, Discovery and Resource Access Using Embedded Web Services

Smart embedded objects such as sensors and actuators will become an important part of the Internet of Things. With recent technologies, it has now become possible to deploy a sensor network and interconnect it with IPv6 Internet. However, several manual configuration steps are still needed to integrate a sensor network within an existing networking environment. In this paper we describe a novel self-organization solution to facilitate the deployment of sensor networks and enable the discovery, end-to-end connectivity and service usage of these newly deployed sensor nodes. The proposed approach makes use of embedded web service technology, i.e. the IETF Constrained Application Protocol (CoAP). Automatic hierarchical discovery of CoAP servers is one of the key features, resulting in a brows able hierarchy of CoAP servers, up to the level of the sensor resources, which can be accessed both over CoAP and HTTP and through the use of either DNS names or IPv6 addresses. To demonstrate the feasibility of our approach we have implemented the solution and deployed it on a test setup, which is publicly accessible to everyone.

Flexible unicast-based group communication for CoAP-enabled devices.

Smart embedded objects will become an important part of what is called the Internet of Things. Applications often require concurrent interactions with several of these objects and their resources. Existing solutions have several limitations in terms of reliability, flexibility and manageability of such groups of objects. To overcome these limitations we propose an intermediately level of intelligence to easily manipulate a group of resources across multiple smart objects, building upon the Constrained Application Protocol (CoAP). We describe the design of our solution to create and manipulate a group of CoAP resources using a single client request. Furthermore we introduce the concept of profiles for the created groups. The use of profiles allows the client to specify in more detail how the group should behave. We have implemented our solution and demonstrate that it covers the complete group life-cycle, i.e., creation, validation, flexible usage and deletion. Finally, we quantitatively analyze the performance of our solution and compare it against multicast-based CoAP group communication. The results show that our solution improves reliability and flexibility with a trade-off in increased communication overhead.

A hybrid indoor localization solution using a generic architectural framework for sparse distributed wireless sensor networks

Indoor localization and navigation using wireless sensor networks is still a big challenge if expensive sensor nodes are not involved. Previous research has shown that in a sparse distributed sensor network the error distance is way too high. Even room accuracy can not be guaranteed. In this paper, an easy-to-use generic positioning framework is proposed, which allows users to plug in a single or multiple positioning algorithms. We illustrate the usability of the framework by discussing a new hybrid positioning solution. The combination of a weighted (range-based) and proximity (range-free) algorithm is made. Both solutions separately have an average error distance of 13.5m and 2.5m respectively. The latter result is quite accurate due to the fact that our testbeds are not sparse distributed. Our hybrid algorithm has an average error distance of 2.66m only using a selected set of nodes, simulating a sparse distributed sensor network. All our experiments have been executed in the iMinds testbed: namely at “de Zuiderpoort”. These algorithms are also deployed in two real-life environments: “De Vooruit” and “De Vijvers”.

Enabling the web of things: facilitating deployment, discovery and resource access to IoT objects using embedded web services

Today, the IETF Constrained Application Protocol CoAP is being standardised. CoAP takes the internet of things to the next level: it enables the implementation of RESTful web services on embedded devices, thus enabling the construction of an easily accessible web of things. However, before tiny objects can make themselves available through embedded web services, several manual configuration steps are still needed to integrate a sensor network within an existing networking environment. In this paper, we describe a novel self-organisation solution to facilitate the deployment of constrained networks and enable the discovery, end-to-end connectivity and service usage of these newly deployed sensor nodes. By using embedded web service technology, the need of other protocols on these resource constrained devices is avoided. It allows automatic hierarchical discovery of CoAP servers, resulting in a browsable hierarchy of CoAP servers, which can be accessed both over CoAP and hypertext transfer protocol.

The OCareCloudS project: Toward organizing care through trusted cloud services

The increasing elderly population and the shift from acute to chronic illness makes it difficult to care for people in hospitals and rest homes. Moreover, elderly people, if given a choice, want to stay at home as long as possible. In this article, the methodologies to develop a cloud-based semantic system, offering valuable information and knowledge-based services, are presented. The information and services are related to the different personal living hemispheres of the patient, namely the daily care-related needs, the social needs and the daily life assistance. Ontologies are used to facilitate the integration, analysis, aggregation and efficient use of all the available data in the cloud. By using an interdisciplinary research approach, where user researchers, (ontology) engineers, researchers and domain stakeholders are at the forefront, a platform can be developed of great added value for the patients that want to grow old in their own home and for their caregivers.

Leveraging upon standards to build the Internet of Things

Smart embedded objects will become an important part of what is called the Internet of Things. However, the integration of embedded devices into the Internet introduces several challenges, since many of the existing Internet technologies and protocols were not designed for this class of devices. In the past few years, there were many efforts to enable the extension of Internet technologies to constrained devices. Initially, this resulted in proprietary protocols and architectures. Later, the integration of constrained devices into the Internet was embraced by IETF, moving towards standardized IP-based protocols. Long time, most efforts were focusing on the networking layer. More recently, the IETF CoRE working group started working on an embedded counterpart of HTTP, allowing the integration of constrained devices into existing service networks. In this paper, we will briefly review the history of integrating constrained devices into the Internet, with a prime focus on the IETF standardization work in the ROLL and CoRE working groups. This is further complemented with some research results that illustrate how these novel technologies can be extended or used to tackle other problems.

Building embedded applications via REST services for the internet of things

As embedded networks are evolving to open systems, its becoming possible to create new applications on top of these existing embedded systems. However, developing new applications can be difficult due to the large diversity of protocols that exist today. In this paper, the authors demonstrate how employing the CoAP protocol can enable rapid application development by re-using well-known principles from the Web development world. Furthermore, we also demonstrate how a number of extensions to CoAP help to lower the barrier for developing applications even further.

Wi-Fi helping out Bluetooth smart for an improved home automation user experience

Home automation devices are becoming increasingly popular in the field of consumer electronics. Various appliances like thermostats, smoke detectors, intelligent lighting systems, etc., have appeared on the market to create a smart home. Vendors have the availability over multiple wireless technologies to connect their products to the smart home and communicate with the user. The most adopted technologies are the ones that can interface directly with a mobile device such as a smartphone or tablet, without the need for an additional gateway. Within this context, Wi-Fi and Bluetooth are the dominant technologies. In this paper we look at home automation devices that have chosen to solely support Bluetooth 4.0 as communication interface. We highlight the downsides of this technology in a home setting and try to mitigate this problem by exploiting the Wi-Fi capabilities of other devices, in particular smartphones. The proposed solution realizes a Wi-Fi bridge on the smartphone that is connected to the Bluetooth device. This enables other smartphone users to connect to the Bluetooth device over the Wi-Fi network, alleviating some of the downsides of the Bluetooth technology.

The Bluetooth Mesh Standard: An Overview and Experimental Evaluation

Mesh networks enable a many-to-many relation between nodes, which means that each node in the network can communicate with every other node using multi-hop communication and path diversity. As it enables the fast roll-out of sensor and actuator networks, it is an important aspect within the Internet of Things (IoT). Utilizing Bluetooth Low Energy (BLE) as an underlying technology to implement such mesh networks has gained a lot of interest in recent years. The result was a variety of BLE meshing solutions that were not interoperable because of the lack of a common standard. This has changed recently with the advent of the Bluetooth Mesh standard. However, a detailed overview of how this standard operates, performs and how it tackles other issues concerning BLE mesh networking is missing. Therefore, this paper investigates this new technology thoroughly and evaluates its performance by means of three approaches, namely an experimental evaluation, a statistical approach and a graph-based simulation model, which can be used as the basis for future research. Apart from showing that consistent results are achieved by means of all three approaches, we also identify possible drawbacks and open issues that need to be dealt with.

Appdaptivity: An Internet of Things Device-Decoupled System for Portable Applications in Changing Contexts

Currently, applications in the Internet of Things (IoT) are tightly coupled to the underlying physical devices. As a consequence, upon adding a device, device replacement or user’s relocation to a different physical space, application developers have to re-perform installation and configuration processes to reconfigure applications, which bears costs in time and knowledge of low-level details. In the emerging IoT field, this issue is even more challenging due to its current unpredictable growth in term of applications and connected devices. In addition, IoT applications can be personalised to each end user and can be present in different environments. As a result, IoT scenarios are very changeable, presenting a challenge for IoT applications. In this paper we present Appdaptivity, a system that enables the development of portable device-decoupled applications that can be adapted to changing contexts. Through Appdaptivity, application developers can intuitively create portable and personalised applications, disengaging from the underlying physical infrastructure. Results confirms a good scalability of the system in terms of connected users and components involved.