LASA: Location-Aware Scheduling Algorithm In Industrial IoT Networks With Mobile Nodes

The Synchronized Single-hop Multiple Gateway (SHMG) is a framework recently proposed to support mobility into 6TiSCH, the standard network architecture defined for Industrial Internet of Things (IIoT) deployments. SHMG supports industrial applications with stringent requirements by adopting the Shared-Downstream Dedicated-Upstream (SD-DU) scheduling policy, which allocates to Mobile Nodes (MNs) a set of dedicated transmission opportunities for uplink data. Such allocation is performed on all the Border Routers (BRs) of the network without considering the location of MNs. Transmission opportunities are reserved also in BRs far from the current location of the MN, resulting in a waste of resources that limits the maximum number of nodes supported by the network. To overcome this problem, we propose a Location-Aware Scheduling Algorithm (LASA) that takes into account the position of MNs to build and maintain an efficient communication schedule. Specifically, LASA tries to prevent conflicts arising due to node mobility, in a preventive manner, so as to minimize packet dropping. We evaluate LASA via simulation experiments. Our results show that LASA allows to increase the number of MNs by more than four times, with respect to SD-DU, yet guaranteeing a Packet Delivery Ratio higher than 98%

Mobility Management in Industrial Iot Environments

The Internet Engineering Task Force (IETF) has defined the 6TiSCH architecture to enable the Industrial Inter-net of Things (IIoT). Unfortunately, 6TiSCH does not provide mechanisms to manage node mobility, while many industrial applications involve mobile devices (e.g., mobile robots or wearable devices carried by workers). In this paper, we consider the Synchronized Single-hop Multiple Gateway framework to manage mobility in 6TiSCH networks. For this framework, we address the problem of positioning Border Routers in a deployment area, which is similar to the Art Gallery problem, proposing an efficient deployment policy for Border Routers based on geometrical rules. Moreover, we define a flexible Scheduling Function that can be easily adapted to meet the requirements of various IIoT applications. We analyze the considered Scheduling Function in different scenarios with varying traffic patterns and define an algorithm for sizing the system in such a way to guarantee the application requirements. Finally, we investigate the impact of mobility on the performance of the system. Our results show that the proposed solutions allow to manage node mobility very effectively, and without significant impact on the performance

Biomass Carbonization: Process Options and Economics for Small Scale Forestry Farms☆

Abstract Bioenergy represents a unique opportunity for forestry companies to diversify the sources of income and create new stable business opportunities: a large number of initiatives has started in the last decades especially regarding decentralized power generation; nevertheless the conversion of the farmers to energy producers is not a trivial issue. The present work has focused on a possible alternative to biopower generation for forestry farms: the biomass carbonization (i.e. biomass slow pyrolysis). Charcoal making presents good prerequisite conditions for successful biomass based systems in the forestry sector: the system results incentive-independent, the power generation represents the co-product of a different primary production (resulting a real additional income), the plant capital cost is affordable for small scale farmers, operations requires technical skills normally available in the forestry sector and the reliability of the system is proven and credible, reducing the risks contained in business plans based on "number of hours of operation over several years". Moreover charcoal is a well known product, familiar to forestry companies for a very long time, the market is well defined, the technology is known but still offers opportunities for further improvements (in terms of efficiency, costs and environmental impacts), the technology does not present major risk, the investment is well suited to small farmers and the process and technology gives a great opportunity for small scale and local supply chain development. Based on these considerations, the present work investigated the technological opportunities for small scale charcoal making systems. Various process configurations have been examined, focusing on advantages and disadvantages representative of each solution in view of small scale application suitable for the Italian case and a designed pilot plant has been proposed

Autothermal biochar production and characterization at pilot scale

The present work reports on the results from the validation campaign of an autothermal pilot carbonization unit (CarbON) and on the characterization of the produced biochar and pyrolysis vapors. The proposed pilot plant leverages the simplicity and effectiveness of autothermal operations together with open top, downdraft design, to bring to the small scale the performance of larger installations. In autothermal operation, heat for the process is internally provided by combusting part of the feedstock and evolved volatiles inside the reactor, the so called “oxidative pyrolysis”. Please click on the file below for full content of the abstract

integration of srf and carbonization plant for small forestry farms

Abstract A continuous oxidative carbonization pilot unit, with a capacity of 50 kg/h,has been developed and builtby RE-CORD; reported performance data shows that the unit can produce high quality charcoal, suitable for BBQ, metallurgy of activated-carbon manufacturing, as well as biochar. Charcoal yield in excess of 24 wt% (dry) has been achieved, with a fixed carbon content higher than 85 wt% (dry). In this work,the up-scaled 250 kg/h demo plant has been designed, and the construction, operation and maintenancecosts estimated. It was assumed to feed the plant with a dedicated SRF of either poplar or robinia, which represents a very innovative and yet unexplored value chain. Performance data are reported along with economic evaluation of the whole chain. Results shows how aland management scheme based on SRF coupled to innovative small-scale biomass carbonization technology represents an appealing opportunity for business diversification in small and medium forestry enterprises

Mobility in the Industrial Internet of Things: a performance analysis

The Industrial Internet of Things (IIoT) is an evolution of the traditional Internet of Things (IoT) to include industrial applications with stringent requirements, in terms of reliability and timeliness. To promote the IIoT, the Internet Engineering Task Force (IETF) has defined the 6TiSCH architecture that allows to integrate IoT devices into existing IPv6 networks ensuring the stringent reliability and timeliness requirements of industrial applications. So far, 6TiSCH has been used with static nodes and many solutions for 6TiSCH networks have been developed under this (implicit) assumption. However, node mobility may be an opportunity in industrial settings, as many industrial things may be mobile (e.g., mobile robots). In this thesis, we consider and evaluate an architecture for supporting mobility in 6TiSCH networks. Specifically, we develop MobileTiSCH, a module for the OMNeT++ simulation tool implementing the considered architecture, and use it to evaluate the performance of the above-mentioned architecture depending on various parameters, such as number of border routers, number of mobile nodes, resource allocation, mobility pattern, etc

Mass and energy balances of an autothermal pilot carbonization unit

The CarbOn pilot plant is a continuous biomass carbonization system, rated for a capacity of up to 50 kg h−1 and based on open top, downdraft technology, operating in oxidative pyrolysis in the temperature range of 500–650 °C and equivalence ratio (ER) between 0.1 and 0.2. In the reported validation tests, carried out on small size chestnut woodchips, charcoal mass yield in excess of 22.4 ± 0.7 wt% (dry base) has been achieved, with a fixed carbon content higher than 85 wt% (dry base). The fixed carbon yield (FCy) was 18.2 ± 2.2 wt% (dry base), the char carbon yield (CCy) 38.3 ± 1.6 wt% (dry base) and the net energy conversion efficiency to char (ε) equal to 41.2 ± 2.2% (wet base). Volume concentration of permanent gases in the pyrolysis vapors and condensable species were also measured before incineration and critically compared against literature data. The organic condensate from oxidative pyrolysis was obtained as 4.9 wt% of the dry biomass, and around 58 wt% of its constituents have been identified; in order of decreasing abundance, the organic fraction of condensate was composed of organic acids, aromatics, furans, anhydrous sugars, phenols, methanol, PAHs, acetaldehyde, ketones. Measured and calculated performance data shows that the pilot unit can produce high quality charcoal, meeting and exceeding the product specifications set by standard EN 1860-2 for BBQ lump charcoal as well as those set forth by international voluntary standards on biochar quality for soil application