Efficient vertical handover in heterogeneous low-power wide-area networks

As the Internet of Things (IoT) continues to expand, the need to combine communication technologies to cope with the limitations of one another and to support more diverse requirements will proceed to increase. Consequently, we started to see IoT devices being equipped with multiple radio technologies to connect to different networks over time. However, the detection of the available radio technologies in an energy-efficient way for devices with limited battery capacity and processing power has not yet been investigated. As this is not a straightforward task, a novel approach in such heterogeneous networks is required. This article analyzes different low-power wide-area network technologies and how they can be integrated in such a heterogeneous system. Our contributions are threefold. First, an optimal protocol stack for a constrained device with access to multiple communication technologies is put forward to hide the underlying complexity for the application layer. Next, the architecture to hide the complexity of a heterogeneous network is presented. Finally, it is demonstrated how devices with limited processing power and battery capacity can have access to higher bandwidth networks combined with longer range networks and on top are able to save energy compared to their homogeneous counterparts, by measuring the impact of the novel vertical handover algorithm

Rejections in an non-purpose bred assistance dog population : reasons, consequences and methods for screening

Assistance dogs aid people with various impairments on a daily basis. To become an assistance dog, a strict selection procedure and intensive training period must be successfully completed. Consequently, not every dog acquired for this purpose, becomes an assistance dog. The purpose of this study was to investigate reasons for failure and the financial consequences thereof for assistance dog associations that do not have a dedicated breeding program for their dogs. Data were collected for a total of 537 dogs enlisted between 2001 and 2015 and purchased out of the general dog population by five Belgian assistance dog associations. Only 60 percent of the dogs actually became an assistance dog and the main reasons for failure were related to undesirable behavioural characteristics and orthopaedic disorders. The estimated average financial loss per rejected dog was found to be 10524 euro. A detailed comparison of the two most popular breeds (Golden Retriever and Labrador Retriever) within the guide dogs and mobility assistance dogs revealed no significant difference in probability of successfully completing the training. However, a comparison of orthopaedic screening methods revealed a higher rejection with computed tomography for elbow dysplasia and laxity-based radiographical techniques for hip dysplasia compared to radiography and the standard ventrodorsal hip extend radiograph alone, respectively. Based on these results, we provide several suggestions to increase the probability of success

Device discovery and context registration in static context header compression networks

Due to the limited bandwidth of Low-Power Wide-Area Networks (LPWAN), the application layer is currently often tied straight above the link layer, limiting the evolution of sensor networks distributed over a large area. Consequently, the highly efficient Static Context Header Compression (SCHC) standard was introduced, where devices can compress the IPv6 and upper layer protocols down to a single byte. This approach, however, assumes that every compression context is distributed before deployment, again limiting the evolution of such networks. Therefore, this paper presents two context registration mechanisms leveraging on the SCHC adaptation layer. This is done by analyzing current registration solutions in order to find limitations and optimizations with regard to very constrained networks. Both solutions and the current State-of-The-Art (SoTA) are evaluated in a Lightweight Machine to Machine (LwM2M) environment. In such situation, both developed solutions decrease the energy consumption already after 25 transmissions, compared with the current SoTA. Furthermore, simulations show that Long Range (LoRa) devices still have a 80% chance to successfully complete the registration flow in a network with a 50% Packet Error Ratio. Briefly, the work presented in this paper delivers bootstrapping tools to constrained, SCHC-enabled networks while still being able to reduce energy consumption

Decentralized linked open data in constrained wireless sensor networks

Data generated by sensors in Internet of Things ecosystems contains lots of valuable information, which is often not used to its full potential. This is mainly due to the fact that data is stored in proprietary storages and formats. Manufacturers of sensor devices often offer closed platforms to view and manage the data, which limits their reusability. Moreover, questions start to raise about true data ownership over data generated from monitoring our everyday lives. In order to overcome these issues several initiatives have emerged in the past to hand over data to the rightful owner. One of these initiatives is Solid, currently focusing on socially linked data. However, never before did one apply the Solid principles to Internet of Things data. Therefore, in this paper, a novel approach is presented where sensor data is handled from sensor to storage using open data formats and standards to ensure interoperability and reusability. It is shown that combining existing concepts can be helpful in designing decentralized Internet of Things data storages, on top of which data can be incorporated into the Linked Open Data cloud. This has been done by comparing the overhead of a regular approach, using Linked Open Data concepts on top of a sensor device, to an approach that was optimized for device management in constrained Internet of Things networks

An integrated decision support tool for the prediction and evaluation of efficiency, environmental impact and total social cost of forestry projects in the framework of the Kyoto Protocol

For the implementation of the Kyoto Protocol, governments of annex I countries need to develop strategies and policies for greenhouse gas reduction. Land use, land use change and forestry (LULUCF) offer CO2 emission reduction opportunities both home and abroad. Selection of effective forestry opportunities is a complex decision process based on multiple information concerning the greenhouse gas emission reduction potential, the environmental impacts and the cost efficiency of potential scenarios. In this paper, a decision support framework to evaluate forestry scenarios for greenhouse gas emission reduction was presented and tested on five different scenarios (existing and new multifunctional forest in Flanders, Belgium, energy crop with short rotation poplar, energy crop with annually harvested Miscanthus, forest plantation in the subtropics, and conservation of tropical rainforest). The framework is organized as a serial connection of a carbon accounting module, an environmental module and an economic module. Modules include a combination of models and quantitative assessments procedures. In order to make scenarios comparable, the environmental and economic modules calculate their outputs on a functional unit basis of 1 ton CO2 emission reduction. The framework is universally applicable, straightforward, transparent and quantitative. Data requirements are medium, but applicability is fairly complex due to the interdisciplinary character of the tool. Further developments would require automated data flows between models and a user interface. As to the results of the scenario analysis, the only attractive possibility for sinks in Flanders is the establishment of new multifunctional forests. This even yields a net benefit because it replaces the generally loss-making agriculture and, in addition, yields other environmental and recreational benefits. The establishment of bioenergy plantations is a very efficient way of reducing CO2 as far as land occupation and environmental impacts are concerned. However, it also turns out to be a very expensive option. Plantation forestry in the tropics is advantageous when evaluated over longer periods of time. Conservation of tropical forest does not come into consideration as a CDM project, but is nevertheless economically attractive for Flanders since the cost per ton CO2 emission reduction is in the neighborhood of the world market price.CO2 emission reduction, carbon balance, Life Cycle Assessment, Land use impact, Cost benefit analysis

Using SCHC for an optimized protocol stack in multimodal LPWAN solutions

Low Power Wide Area Networks (LPWANs) are formed out of cheap, small, interconnected devices which operate in the sub-GHz domain. The last couple of years, many communication technologies arose in this domain, each with its own characteristics. In order to satisfy more diverse requirements, devices are now equipped with multiple LPWAN radio technologies, which requires the use of a unified protocol stack independent of the underlying LPWAN technology. With its 2128 addresses available and its ability to operate over different link layer technologies, the IPv6 protocol stack would be the ideal candidate. However, many LPWAN configurations do not allow standardized IP/UDP communication, sometimes acquiring more header overhead than there is room for the actual payload. Recently, a new initiative to directly connect constrained devices over IP was initiated by the LPWAN working group of the Internet Engineering Task Force (IETF). This work resulted in the Static Context Header Compression or SCHC mechanism. This header compression mechanism is able to compress the overhead of these internet protocols up to 95%. In order to comply with the IPv6 Maximum Transfer Unit (MTU) of 1280 bytes, a fragmentation mechanism is also included. In this work, we validate the benefits of using SCHC for multimodal LPWAN solutions and show its implementation feasibility on such constrained devices

Killing individual poultry on-farm-a survey among veterinarians and farmers

To date, information about reasons to select and kill poultry on-farm and which method veterinarians and poultry producers preferably use is scarce. Little is also known about their knowledge of the legislation regarding on-farm killing methods and of methods alternative to the one(s) they use, as well as their perception of those alternatives. In this study, Flemish poultry veterinarians (n = 13), broiler chicken producers (n = 27), and turkey producers (n = 4) were surveyed on killing methods they currently use in practice and alternative methods, on their opinion about what constitutes an appropriate method for on-farm killing of poultry, and on their reasons for killing. All poultry veterinarians and chicken producers who filled out the survey kill poultry by manual cervical dislocation (CD), whereas some turkey farmers also indicated killing by percussive blow to the head (n = 1) or exsanguination (n = 1). Turkey producers seem to be more inclined not to kill animals with injuries or symptoms of disease as compared to veterinarians or chicken producers, such that moribund turkeys are more likely to remain in the flock. Veterinarians considered the following properties of a killing method important: animal friendliness, applicability inside the stable, a high success rate, and time efficiency. Producers ranked the properties similarly, but for them, ease of performance and cost efficiency were more important than applicability inside the stable. Producers scored those killing properties rather positively for manual as well as mechanical CD. Veterinarians and chicken producers considered the captive bolt method to be easy to perform, to have a high success rate, to be feasible to perform in the stable, and to be animal friendly. Turkey producers, however, had doubts about the latter 2 properties. Gas, injection, and electrocution were inferior methods to kill poultry according to producers. In conclusion, manual CD is the most common method for killing broiler chickens and turkeys, and knowledge of, and experience with, alternative methods is very limited, both among veterinarians and producers. Informing them about legislation and training for the use of alternative killing techniques are recommended

Design and evaluation of a scalable Internet of Things backend for smart ports

Internet of Things (IoT) technologies, when adequately integrated, cater for logistics optimisation and operations' environmental impact monitoring, both key aspects for today's EU ports management. This article presents Obelisk, a scalable and multi-tenant cloud-based IoT integration platform used in the EU H2020 PortForward project. The landscape of IoT protocols being particularly fragmented, the first role of Obelisk is to provide uniform access to data originating from a myriad of devices and protocols. Interoperability is achieved through adapters that provide flexibility and evolvability in protocol and format mapping. Additionally, due to ports operating in a hub model with various interacting actors, a second role of Obelisk is to secure access to data. This is achieved through encryption and isolation for data transport and processing, respectively, while user access control is ensured through authentication and authorisation standards. Finally, as ports IoTisation will further evolve, a third need for Obelisk is to scale with the data volumes it must ingest and process. Platform scalability is achieved by means of a reactive micro-services based design. Those three essential characteristics are detailed in this article with a specific focus on how to achieve IoT data platform scalability. By means of an air quality monitoring use-case deployed in the city of Antwerp, the scalability of the platform is evaluated. The evaluation shows that the proposed reactive micro-service based design allows for horizontal scaling of the platform as well as for logarithmic time complexity of its service time