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

The Hazards of Building in the Vicinity of Electromagnetic Fields: Lessons for Building Code Enforcement in Nigeria

This paper dealt with the topic of electromagnetic field (EMF) and its effects on building occupants when such buildings are located within the vicinity of the field. Two main sources of EMF, namely, high voltage power transmission lines and cellular towers, were reviewed. Empirical evidence revealed that they have a tendency to emit electromagnetic fields and they have been determined to be hazardous to building occupants. Studies have also established that when buildings are erected within an unsafe distance to the fields, occupants of such buildings become exposed to health risks. Indeed, evidence exists to show that exposure to these fields can lead to cancer in children and that men exposed to the fields are also susceptible to health risks. Studies by the International Agency for  Research on Cancer (IARC) among others, assessed the carcinogenicity of radiofrequency electromagnetic fields (RF-EMF) positing that human responses to RF-EMF can occur from use of personal devices such as mobile telephones, cordless phones, Bluetooth, and amateur radios; from occupational sources such as high frequency dielectric and induction heaters, and high-powered  pulsed radars. Exposures can also occur from environmental sources such as mobile phone base stations, broadcast antennas, and medical applications. This paper also examined standards for safe distances and buffers for building location with respect to EMFs and made recommendations for policy makers and building code enforcement services. Keywords: Building Codes, Epidemiology, Carcinogenicity, Radio Frequency, Extreme Low Frequency, Non-Ionizing Radiation DOI: 10.7176/JETP/9-3-01 Publication date:March 31st 201

The Combined Effect of In-Situ Tumor and Irradiation on Peritumoral Brain Vasculature

In the USA, 200,000 brain tumors are diagnosed each year with glioma representing 8.4% of the 200,000. The standard treatment for glioma consists of surgical resection, when possible, followed by radiation therapy (RT) and/or chemotherapy. Radiation therapy is one of the most effective treatments of brain tumors; however, the therapeutic ratio of RT is limited by damage to the normal tissue. We hypothesize that tumor growth has an adverse effect on the peritumoral tissue through the angiogenic/inflammatory environment it creates rendering it susceptible to further damage by RT which may be prevented by using anti-angiogenic/anti-inflammatory agents. We have developed a rat C6 glioma brain tumor model to study the combination of tumor presence and radiation treatment on the peritumoral region both at early and late time points. We have also used this model to test the effect of thalidomide on limiting radiation toxicity to the normal tissue while not interfering with radiation efficacy. Intravital microscopy was used in combination with a cranial window brain tumor model to assess the effect of glioma presence on neighboring tissue with and without RT (40Gy total, 8Gy/day starting on day 5 post-implant/surgery) and when RT was administered in combination with thalidomide (100mg/kg/day). Permeability of the blood-brain barrier (BBB) was determined by measuring the rate of extravasation of 3kDa Texas-Red dextran from the vasculature into the tissue. Leukocytes were stained using an intravenous injection of Rhodamine 6G and leukocyte interactions, an indicator of inflammation, were counted in venules ranging in size from 45 to 90μm. Staining for vascular endothelial growth factor (VEGF) and glial fibrillary acidic protein (GFAP), a marker of astrocytes, was also performed. Our studies show that the presence of the tumor alone caused quantifiable changes in BBB permeability, and caused an increased in vascular endothelial growth factor (VEGF) protein expression in the peritumoral region. Astrogliosis, an increase in reactive astrocytes associated with inflammation, was detected in the peritumoral region and contralateral to the tumor. RT of the implanted tumors caused a significant increase in BBB permeability and in adhered leukocytes in the peritumoral region, compared to the sham implant group. In addition following RT, VEGF increased both in the peritumoral region and in the middle of the tumor. Astrogliosis was also significantly higher in the tumor implant + RT animals compared to sham and tumor implanted animals. At 66 days post tumor-implantation the RT the BBB permeability and astrogliosis were still significantly higher compared to sham implanted animals. We have also evaluated thalidomide as a potential anti-angiogenic/anti-inflammatory agent with the prospective to protect normal tissue and have shown that it had limited effects in a rat C6 brain tumor model and it interfered with RT tumor treatment efficacy. In addition, at 66 post tumor implant there was a significantly higher incidence of astrogliosis, BBB permeability, and adhered leukocyte counts in the animals treated with thalidomide compared to sham implanted animals. In this work, we have developed and characterized a new rat radiation brain tumor model to study the effect of a brain tumor and RT on the normal brain tissue at acute and late time points. We have quantified the effect of tumor presence on the peritumoral microvasculature and observed a significant increase in vascular permeability but no significant effect on leukocyte interactions. The lack of leukocyte interactions might indicate that the increase in permeability is associated with the angiogenic signaling induced by tumor presence. In support of this conclusion, we observed an increased VEGF expression in the peritumoral region. The combination of RT and tumor presence had a greater damaging effect on peritumoral BBB integrity measured by an increase in leukocyte interactions and permeability which could not be inhibited by using thalidomide. Furthermore, the regression of tumor after RT and the achievement of 100% survival at 65 days post implant have allowed us to investigate late radiation damage

Wireless networks and EMF-paving the way for low-EMF networks of the future: the LEXNET project

While, according to the World Health Organization, no adverse health effects of radio-frequency (RF) electromagnetic fields (EMFs) have been established to date, EMF exposure from wireless communication networks is nonetheless often cited as a major cause of public concern and is frequently given considerable media coverage. This article presents the results of a new survey on RF-EMF exposure risk perception together with a comprehensive overview of the EMF footprint of existing and emerging networks. On the basis of these findings, we then put forward the rationale for EMF-aware networking. Subsequently, we highlight the gaps in existing systems, which impede EMF-aware networking, and outline the key concepts of the recently launched European Union (EU) Seventh Framework Programme (FP7) Integrated Project Low-EMF Exposure Future Networks (LEXNET): a new, all-encompassing, population-based metric of exposure and ways it can be used for low-EMF, quality of service (QoS)-aware network optimization.This paper reports work undertaken in the context of the project LEXNET. LEXNET is a project supported by the European Commission in the 7th Framework Programme (GA n°318273). For further information, please visit www.lexnet-project.e

ATTO: Wireless Networking at Fiber Speed

ATTO targets wireless networking at fiber speed: 100 Gb/s/m(2) with latencies smaller than 10 mu s. To provide this tremendous wireless capacity, ultrasmall floor-integrated cells are proposed. In this way, short-reach communication can be established, reducing the effect of interference and providing full frequency reuse in the wireless domain. Radio frequency (RF)-overfiber coherent communication and a dedicated 2-D passive optical network structure support the interconnection and selection of the cells and minimize the required transceiver electronics. To evaluate the feasibility of the proposed architecture, key principles are validated at lower frequency bands. Two main building blocks are addressed in this paper: a fully passive opto-antenna to prove that a passive remote antenna head can be realized owing to the short transmission distances. Furthermore, a low-cost RF-overfiber system is demonstrated: sigma-delta modulation drives nonlinear optical modulators, such as electroabsorption modulators and vertical-cavity surface-emitting lasers, using a digital transmitter while remaining compatible with the passive opto-antenna. Finally, two important properties of the ATTO floor are evaluated. The exposure of a human body model to RF fields by the antenna floor. Measurements ensure a 200-fold margin with respect to the International Commission on Non-Ionizing Radiation Protection basic restriction. To guarantee that multiple devices can communicate with the ATTO floor simultaneously, the interference between cells spaced 300 mm apart was evaluated

Compliance of corporate businesses to health and environment standards. The case of cell phone towers in Egypt

This study explores the compliance of corporate businesses to the health and environment standards especially, the construction of cell phone towers, in Egypt. Also, it examines to what extent the mobile companies in Egypt adhere to the health and environment standards, namely in the residential areas (informal and poor areas). It demonstrates how the standards set in Egypt are not applied restrictively enough to ban the violations. Besides, there are negative impacts that might be found as a result of not complying with the health standards. In this study, the qualitative research methods were used in the form of in-depth interviews with the three mobile companies (Vodophone, Mobinil, Etisalat) and the Egypt governmental body (NTRA). The research findings showed that mobile companies in Egypt do not comply with the health and environment standards in many cases. In terms of health and environment standards, the study, based on the interviews in addition to the literature review, showed that setting up cell phone tower stations on the buildings\u27 roofs has negative impact in case of not complying with standards. Therefore, it could be considered as a source of danger, especially, to those who live close to towers. Also, the NTRA’s standards are not strong enough to ban the violations compared to other countries (Turkey, Tunisia, and South Africa). Moreover, the study reveals some reasons behind the violations such as: delivering good coverage, people’s attitude, building violations, and the most important reason is the weak role of the governmental body represented by the NTR