Wireless indoor network planning for advanced exposure and installation cost minimization

The possibility of having information access anytime and anywhere has caused a huge increase of the popularity of wireless networks. Requirements of users and owners have been ever-increasing. However, concerns about the potential health impact of exposure to radio frequency (RF) sources have arisen and are getting accounted for in wireless network planning. In addition to adequate coverage and reduced human exposure, the installation cost of the wireless network is also an important criterion in the planning process. In this paper, a hybrid algorithm is used to optimize indoor wireless network planning while satisfying three demands: maximum coverage, minimal full installation cost (cabling, cable gutters, drilling holes, labor, etc.), and minimal human exposure. For the first time, wireless indoor networks are being optimized based on these advanced and realistic conditions. The algorithm is investigated for three scenarios and for different configurations. The impact of different exposure requirements and cost scenarios is assessed

An efficient genetic algorithm for large-scale planning of robust industrial wireless networks

An industrial indoor environment is harsh for wireless communications compared to an office environment, because the prevalent metal easily causes shadowing effects and affects the availability of an industrial wireless local area network (IWLAN). On the one hand, it is costly, time-consuming, and ineffective to perform trial-and-error manual deployment of wireless nodes. On the other hand, the existing wireless planning tools only focus on office environments such that it is hard to plan IWLANs due to the larger problem size and the deployed IWLANs are vulnerable to prevalent shadowing effects in harsh industrial indoor environments. To fill this gap, this paper proposes an overdimensioning model and a genetic algorithm based over-dimensioning (GAOD) algorithm for deploying large-scale robust IWLANs. As a progress beyond the state-of-the-art wireless planning, two full coverage layers are created. The second coverage layer serves as redundancy in case of shadowing. Meanwhile, the deployment cost is reduced by minimizing the number of access points (APs); the hard constraint of minimal inter-AP spatial paration avoids multiple APs covering the same area to be simultaneously shadowed by the same obstacle. The computation time and occupied memory are dedicatedly considered in the design of GAOD for large-scale optimization. A greedy heuristic based over-dimensioning (GHOD) algorithm and a random OD algorithm are taken as benchmarks. In two vehicle manufacturers with a small and large indoor environment, GAOD outperformed GHOD with up to 20% less APs, while GHOD outputted up to 25% less APs than a random OD algorithm. Furthermore, the effectiveness of this model and GAOD was experimentally validated with a real deployment system

An efficient genetic algorithm for large-scale transmit power control of dense and robust wireless networks in harsh industrial environments

The industrial wireless local area network (IWLAN) is increasingly dense, due to not only the penetration of wireless applications to shop floors and warehouses, but also the rising need of redundancy for robust wireless coverage. Instead of simply powering on all access points (APs), there is an unavoidable need to dynamically control the transmit power of APs on a large scale, in order to minimize interference and adapt the coverage to the latest shadowing effects of dominant obstacles in an industrial indoor environment. To fulfill this need, this paper formulates a transmit power control (TPC) model that enables both powering on/off APs and transmit power calibration of each AP that is powered on. This TPC model uses an empirical one-slope path loss model considering three-dimensional obstacle shadowing effects, to enable accurate yet simple coverage prediction. An efficient genetic algorithm (GA), named GATPC, is designed to solve this TPC model even on a large scale. To this end, it leverages repair mechanism-based population initialization, crossover and mutation, parallelism as well as dedicated speedup measures. The GATPC was experimentally validated in a small-scale IWLAN that is deployed a real industrial indoor environment. It was further numerically demonstrated and benchmarked on both small- and large-scales, regarding the effectiveness and the scalability of TPC. Moreover, sensitivity analysis was performed to reveal the produced interference and the qualification rate of GATPC in function of varying target coverage percentage as well as number and placement direction of dominant obstacles. (C) 2018 Elsevier B.V. All rights reserved

Exposure optimization in indoor wireless networks by heuristic network planning

Due to the increased use of indoor wireless networks and the concern about human exposure to radio-frequency sources, exposure awareness has increased during recent years. However, current-day network planners rarely take into account electric-field strengths when designing networks. Therefore, in this paper, a heuristic indoor network planner for exposure calculation and optimization of wireless networks is developed, jointly optimizing coverage and exposure, for homogeneous or heterogeneous networks. The implemented exposure models are validated by simulations and measurements. As a first novel optimization feature, networks are designed that do not exceed a user-defined electric-field strength value in the building. The influence of the maximally allowed field strength, based on norms in different countries, and the assumed minimal separation between the access point and the human are investigated for a typical office building. As a second feature, a novel heuristic exposure minimization algorithm is presented and applied to a wireless homogeneous WiFi and a heterogeneous WiFi-LTE femtocell network, using a new metric that is simple but accurate. Field strength reductions of a factor 3 to 6 compared to traditional network deployments are achieved and a more homogeneous distribution of the observed field values on the building floor is obtained. Also, the influence of the throughput requirement on the field strength distribution on the building floor is assessed. Moreover, it is shown that exposure minimization is more effective for high than for low throughput requirements and that high field values are more reduced than low field values

CHARACTERIZATION OF HOTSPOT COVERAGE PLAN IN 2.4/ 5GHZ FREQUENCY BAND (NNAMDI AZIKIWE UNIVERSITY, NIGERIA, AS A CASE STUDY)

Research and tertiary institutions today uses wireless connectivity owing to the benefits of mobility flow-awarecommunication and flexibility advantages generally. In this case, mobility computing involving the use of smartdevices, laptops, wifi-desktops, etc, largely depends on a deployed hotspot infrastructure. In particular, the physicalposition of the mobile system (and hence of the user) and the hotspot infrastructure design layout are fundamentalconsiderations for service efficiency. While previous works have focused on user position estimation, signal strengthquality and network QoS, this work leverages the contemporary challenges of network connectivity in tertiaryinstitutions in Nigeria with respect to optimal coverage and cost minimization. Using Nnamdi Azikiwe University-Unizik, Awka as testbed, we carried out a study on hotspot/WLAN IEEE 802.11 deployments while devising a costeffective coverage plan in 2,4/5GHz frequency band. A mathematical model on cost optimization for WLANHotpot project processes was developed using Linear programming, the installation procedure, coverage plan basedon specifications of the deployment hardware, and data security were covered in this work. Consequently, from themodel, we argue that with careful selection of optimization criteria in the deployment, an efficient design cost plan,and QoS, could eliminate possible trade-offs in the deployment contexts by over 95%.Keywords: Mobility, Flow-aware, Hotspot, Infrastructure, Optimization, Design, Minimizatio

A survey and tutorial of electromagnetic radiation and reduction in mobile communication systems

This paper provides a survey and tutorial of electromagnetic (EM) radiation exposure and reduction in mobile communication systems. EM radiation exposure has received a fair share of interest in the literature; however, this work is one of the first to compile the most interesting results and ideas related to EM exposure in mobile communication systems and present possible ways of reducing it. We provide a comprehensive survey of existing literature and also offer a tutorial on the dosimetry, metrics, international projects as well as guidelines and limits on the exposure from EM radiation in mobile communication systems. Based on this survey and given that EM radiation exposure is closely linked with specific absorption rate (SAR) and transmit power usage, we propose possible techniques for reducing EM radiation exposure in mobile communication systems by exploring known concepts related to SAR and transmit power reduction in mobile systems. Thus, this paper serves as an introductory guide to EM radiation exposure in mobile communication systems and provides insights toward the design of future low-EM exposure mobile communication networks

Planificación en redes de área local inalámbricas en escenarios internos: elementos, herramientas y cuestiones prácticas

En la actualidad unas de las dificultades que presentan las redes inalámbricas de área local (WLAN) en espacios internos, por ejemplo, edificios, oficinas, distribución de cubículos entre pisos, es la adecuada cobertura a la cual tiene acceso diversos tipos de artefactos como son los celulares, laptops, computadoras, a través de la conexión inalámbrica que provee los diversos puntos de acceso (AP) distribuidos en diversos espacios por dónde transitan o trabajan las personas. En este artículo presentamos un análisis de los escenarios internos, al considerar una serie de elementos básicos, características, herramientas y cuestiones prácticas en el momento de la planificación de una red inalámbrica. Existen una serie de herramientas como inSSIDer, NetSurveyor, NetSpot y Vistumbler orientados a la planificación y diseño de redes LAN inalámbricas 802.11 a/b/g/n/ac en la obtención de rendimiento, seguridad y cumplimiento óptimo de la red. Los resultados obtenidos mediante experimentación permiten obtener información relevante para el planificador de la red encargado de diseñar e implementar la red LAN inalámbrica. De igual modo, se hace uso de una serie de escenarios para la simulación, los cuales están configurados con ciertas características, lo que permite la verificación de la velocidad de conexión, frecuencia de la señal y capacidad de transmisión afrontando las etapas de congestión de la red

iSEA: IoT-based smartphone energy assistant for prompting energy-aware behaviors in commercial buildings

Providing personalized energy-use information to individual occupants enables the adoption of energy-aware behaviors in commercial buildings. However, the implementation of individualized feedback still remains challenging due to the difficulties in collecting personalized data, tracking personal behaviors, and delivering personalized tailored information to individual occupants. Nowadays, the Internet of Things (IoT) technologies are used in a variety of applications including real-time monitoring, control, and decision-making due to the flexibility of these technologies for fusing different data streams. In this paper, we propose a novel IoT-based smartphone energy assistant (iSEA) framework which prompts energy-aware behaviors in commercial buildings. iSEA tracks individual occupants through tracking their smartphones, uses a deep learning approach to identify their energy usage, and delivers personalized tailored feedback to impact their usage. iSEA particularly uses an energy-use efficiency index (EEI) to understand behaviors and categorize them into efficient and inefficient behaviors. The iSEA architecture includes four layers: physical, cloud, service, and communication. The results of implementing iSEA in a commercial building with ten occupants over a twelve-week duration demonstrate the validity of this approach in enhancing individualized energy-use behaviors. An average of 34% energy savings was measured by tracking occupants’ EEI by the end of the experimental period. In addition, the results demonstrate that commercial building occupants often ignore controlling over lighting systems at their departure events that leads to wasting energy during non-working hours. By utilizing the existing IoT devices in commercial buildings, iSEA significantly contributes to support research efforts into sensing and enhancing energy-aware behaviors at minimal costs

Holdsworth Retrofit and Renovation

The University of Massachusetts has a rapidly evolving commitment to reducing greenhouse gas emissions and improving the environmental sustainability of its operations. According to the most recent IPCC report, the buildings sector has more potential to contribute to climate change mitigation than any other sector.1 The energy efficient designs of the current spate of building projects are indicative of the University’s commitment to green building—reducing the energy intensity of the university relative to building area and activities. However, these efforts cannot reduce the total energy use or greenhouse gas emissions from current levels. Among the University’s assets with the greatest potential to achieve these goals are its existing buildings. Most of these are good buildings that have not reached the end of their useful life. Forty-two buildings, encompassing more than half of the general administration and educational space fall into the categories of “catch up and keep up” or “keep and renew” according to the university’s Building Disposition Report.2 Many of the existing buildings have great historical, aesthetic, and emotional value and have stood the test of time as the site of the academic, scientific, and cultural work that is their primary purpose. Can these buildings be updated to dramatically reduce their energy consumption and allow them to continue to function as valuable assets for the long term? What levels of energy savings are possible and reasonable? This report is designed to answer these questions for one representative building: Holdsworth Hall. The recommendations in this report are the product of a detailed and careful examination and exploration of the building and its operations. The investigations and proposed solutions are motivated by two principles: First, the architectural intention should be respected. The building as designed works well on many levels, and no recommendation should undermine currently effective systems and designs or compromise the aesthetic intention of its designers. Second, the building is a complex system, and no change can be considered in isolation. Single measures may achieve savings, but cannot maximize savings or performance without complementary changes in related systems. A final package of recommended measures will define a new building system with emergent properties that make for a qualitatively different and better building beyond simple energy consumption metrics. 1