Search results for "Network"

From Global to Local Disaster Resilience

2015

Implementation of a PLC Field Analyzer on a G3 Modem Platform

2021

Nowadays, power line communications (PLC) are a widely used technology in distribution grids, both for automatic meter reading and automation applications. PLC performances (in terms of capacity, coverage, robustness, and data transmission rate) can be significantly affected by electrical network topologies, connected loads and disturbances. Thus, utilities and modem manufacturers are increasing their interest in electrical network characterization. In this framework, a software tool is proposed in this paper to measure received signal and noise levels. As case study, it is implemented on a G3 PLC transceiver, widely used for smart metering purposes. In this way, a PLC channel characterizat…

ZigBee networks performance under WLAN 802.11b/g interference

2009

ZigBee is a standard protocol suite for low rate wireless personal area networks (LR-WPANs) and has been widely utilized in various fields. Since both ZigBee and WLAN (802.11b/g) operate in the 2.4GHz unlicensed industrial scientific medical (ISM) frequency band, mutual interference is likely to exist and cause signal degradation. In this paper, an interference analysis model is suggested to obtain an estimate of Packet Error Rate (PER) of a ZigBee network. A ZigBee evaluation kit, AVR RZ200, was implemented for measurement of Packet Loss Ratio (PLR). The measured PLR matches the estimated PER, with varied distances and different center frequency offsets of different channels.

Network Dynamics of an Energy Supply Chain: Applicability of the Network Approach to Analysing the Industrial Ecology Practices of Companies

2006

Currently firms face environmental challenges, which require more emphasis on inter-organisational environmental improvement efforts. A field of study of industrial ecology offers some novel approaches for inter-organisational environmental management. It emphasises symbiotic linkages between firms or other organisations in which waste of one actor is used as raw material by others. The industrial network approach has been suggested as a possible framework for developing managerial implications for industrial ecology. This study analyses an example of an industrial ecosystem with notions of the network theory, and concludes that the industrial network approach is useful in analysing and des…

Inference of Spatiotemporal Processes over Graphs via Kernel Kriged Kalman Filtering

2018

Inference of space-time signals evolving over graphs emerges naturally in a number of network science related applications. A frequently encountered challenge pertains to reconstructing such dynamic processes given their values over a subset of vertices and time instants. The present paper develops a graph-aware kernel-based kriged Kalman filtering approach that leverages the spatio-temporal dynamics to allow for efficient online reconstruction, while also coping with dynamically evolving network topologies. Laplacian kernels are employed to perform kriging over the graph when spatial second-order statistics are unknown, as is often the case. Numerical tests with synthetic and real data ill…

Blockchain based Inter-domain Latency Aware Routing Proposal in Software Defined Network

2018

Border gateway protocol (BGP) version 4 is routing current Internet for more than 20 years. BGP is the only protocol that has proven its routing capability of such size network with continually growing nature. Although BGP is scalable and network layer reachability information it lacks quality of service metrics like latency. BGP routing decision algorithm uses as-path length between autonomous systems (AS) as main factor for most of its best-path calculations. Because of more affordable peering architectures as-path length is generally decreasing in worldwide internet network resulting in less efficient routes for real-time internet protocol traffic. This study proposes future internet arc…

Wireless communication based on Raspberry pi and Codesys for mobile robots using IoT technology

2021

The industrial environment is going through exponential changes, due to the diversity of technological solutions that appear more and more frequently and the increase of productivity at increasing capacities. Due to this fact in the industrial area the number of devices, processing systems, collaborative robots, mobile robots and industrial equipment is increasing more and more. Consequently, there is a need for communication and connectivity of entities, common physical or virtual functioning and decision making, all of which are fundamental to the transition to the new concept of Industry 4.0. This study presents how wireless communication can be achieved in a mobile robotic platform that…

The Valencia Port Authority (VPA): environmental information in the annual report

2012

In recent years, most companies are participating in the disclosing of information on the impact of their potential activities on the environment. In 2002, Spain developed its legislation on environmental information in annual reports. The port industry has a potential environmental and economic impact. In this context, it is important to know how it disclosure environmental information in the annual reports. The case of study shows the disclosure information characteristics of Valencia Port Authority (VPA) and the relationships with the environment. The results concluded that VPA has adapted its information not only the standards but as a mean of legitimation.

The dynamics over the next few years of the Spanish mobile telecommunications market share: a mathematical modelling approach

2013

Taking into account available data from 2002 to 2009 about the market share percentages of the Spanish mobile telecommunications service providers, a dynamic diffusion model to study the evolution of the clients’ change between the different companies during the period 2010–2016 is proposed. The constructed model provides a tool for forecasting short-term trends about the customers’ preferences with respect to mobile network operators taking into account both, autonomous decisions due to direct marketing and advertising strategies, and also decisions adopted through interaction via social influence. The model can provide insights to companies for designing strategies in order to gain market…

A Bayesian Learning Automata-Based Distributed Channel Selection Scheme for Cognitive Radio Networks

2014

We consider a scenario where multiple Secondary Users SUs operate within a Cognitive Radio Network CRN which involves a set of channels, where each channel is associated with a Primary User PU. We investigate two channel access strategies for SU transmissions. In the first strategy, the SUs will send a packet directly without operating Carrier Sensing Medium Access/Collision Avoidance CSMA/CA whenever a PU is absent in the selected channel. In the second strategy, the SUs implement CSMA/CA to further reduce the probability of collisions among co-channel SUs. For each strategy, the channel selection problem is formulated and demonstrated to be a so-called "Potential" game, and a Bayesian Lea…