1、 I n t e r n a t i o n a l T e l e c o m m u n i c a t i o n U n i o n ITU-T K.70 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Amendment 4 (12/2014) SERIES K: PROTECTION AGAINST INTERFERENCE Mitigation techniques to limit human exposure to EMFs in the vicinity of radiocommunication stations Amend
2、ment 4: Appendix I New version v.5.0 of the software EMF-estimator Recommendation ITU-T K.70 (2007) Amendment 4 Rec. ITU-T K.70 (2007)/Amd.4 (12/2014) i Recommendation ITU-T K.70 Mitigation techniques to limit human exposure to EMFs in the vicinity of radiocommunication stations Amendment 4 Appendix
3、 I New version v.5.0 of the software EMF-estimator Summary Amendment 4 to ITU-T K.70 consists of a new version (v.5.0) of the software EMF-estimator, which constitutes Appendix I of Recommendation ITU-T K.70 (2007). The main improvements introduced in v.5.0 are the following: the code of the softwar
4、e has been developed and recompiled in the updated programming environment; the installation procedure is new and should be much easier to use; it is possible to open simultaneously many projects, and the results of respective calculations can be directly compared; the term “cumulative exposure“ has
5、 been changed to “total exposure“ following the discussion and decision taken during the development of Recommendation ITU-T K.91. The new version v.5.0 of the software does not run on the Windows XP operational system. The design (layout) of the software and the main options have not changed. Howev
6、er, the format of the projects has changed. The new software gives an opportunity to read the old projects (extension *.exp) and to save them in the new format (extension *.expx). To save all changes in the format of the project file it is necessary to use the “save“ or “save to“ option. This will a
7、llow to fill all the data banks attached to the project file. The software EMF-estimator is provided as an electronic attachment to this amendment. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T K.70 2007-06-29 5 11.1002/1000/9140 1.1 ITU-T K.70 (2007) Amd.1 2009-05-29 5 11
8、.1002/1000/10036 1.2 ITU-T K.70 (2007) Amd.2 2011-05-05 5 11.1002/1000/11351 1.3 ITU-T K.70 (2007) Amd.3 2013-02-07 5 11.1002/1000/11906 1.4 ITU-T K.70 (2007) Amd.4 2014-12-19 5 11.1002/1000/12441 _ * To access the Recommendation, type the URL http:/handle.itu.int/ in the address field of your web b
9、rowser, followed by the Recommendations unique ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T K.70 (2007)/Amd.4 (12/2014) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and
10、communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basi
11、s. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolu
12、tion 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration a
13、nd a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are
14、met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTSITU draws attention to the possi
15、bility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the R
16、ecommendation development process. As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information
17、 and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2015 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T K.70 (2007)/Amd.4 (12/2014) 1 Recommenda
18、tion ITU-T K.70 Mitigation techniques to limit human exposure to EMFs in the vicinity of radiocommunication stations Amendment 4 Appendix I New version v.5.0 of the software EMF-estimator (This appendix does not form an integral part of this Recommendation.) The EMF-estimator software has been devel
19、oped to support the application of the methods described in this Recommendation1. It may help to make an estimation of the cumulative exposure in the vicinity of transmitting stations in the case of many different transmitting systems operating at different frequencies. The EMF-estimator is one of t
20、he available programs which may be used for that purpose. This software is not intended to be used, and in fact cannot be used, for any certification procedure of the transmitting equipment. I.1 Applicability of the EMF-estimator The EMF-estimator software uses the point source model (described in c
21、lause 5.3) and exploits the radiation patterns contained in the attached library or introduced by the user. The radiation pattern may have a full, two-variable 3D form f(,) (a function of azimuth and elevation angles) or may be represented by the horizontal and vertical radiation patterns HRP() and
22、VRP(). The credibility of the calculation is strongly affected by the model used and depends on the region under investigation and available data concerning a transmitting antenna and operating channels (carriers). Generally, the results of calculations are adequate in the far-field region and give
23、acceptable results in most of the radiating near-field region. Depending on the direction, one may expect an overestimation or underestimation of the field in the radiating near-field region. The EMF-estimator should not be used for calculations in the reactive near-filed region because the models o
24、n which it is based are too simple to describe correctly the real conditions determining the EMFs distribution, so for this region the results are not presented by the software. The calculations are more credible if a full radiation pattern f(,) is used. Sufficiently good estimations are also achiev
25、ed if horizontal and vertical radiation patterns HRP() and VRP() are applied. The influence of the radiation pattern and, consequently, the importance of the exactness of its knowledge grows with increasing transmitting antenna gain. In the EMF-estimator package, the library is included, containing
26、examples of the radiation pattern for many typical radiocommunication and broadcast services. One should note, however, that if the radiation patterns are used for antennas which are only similar to those in operation, the results of the calculations should be regarded as an estimation only. In many
27、 practical cases in which radiation levels are far under the limits, such estimation can be sufficient. The input data for the EMF-estimator contains the operating frequency and the size of each transmitting antenna. Based on this data, the area around an object is split into regions of the field. F
28、or the area too close to the transmitting antennas, appropriate information appears on the screen. In practice, only the area in very close proximity to the transmitting antenna (usually with no access for people) cannot be analysed with the use of the EMF-estimator. _ 1 The EMF-estimator software i
29、s included as an electronic attachment to this amendment. 2 Rec. ITU-T K.70 (2007)/Amd.4 (12/2014) The EMF-estimator evaluates: electric field strength; magnetic field strength; the equivalent plane-wave power flux-density; near- and far-field region distances; compliance distances (for general publ
30、ic and occupational exposure); cumulative exposure coefficients Wt and We; reference levels along a line defined by the user and with presented contribution of each component (each source); the cumulative exposure at a height above the ground level defined by the user in a form of the planar chart;
31、there is a possibility to place this chart against the Google map; reference levels related to the ICNIRP or user defined limits. The program uses a library of the radiation patterns for typical antenna systems but there is an opportunity to introduce user-prepared data concerning the transmitting a
32、ntenna radiation pattern. The accuracy of the results of calculations is strongly affected by the accuracy of the input data concerning the transmitting equipment (mainly transmitting antennas). The problem is that, in many cases, the data, especially concerning the radiation patterns, are not avail
33、able or known with limited accuracy. I.2 Typical situation Figure I.1 explains some terms used in the EMF-estimator. Figure I.1 Explanation of some terms used in the EMF-estimator I.3 Software description Figure I.2 shows the main screen of the EMF-estimator with opened project “Figure_8_1“. It cons
34、ists of three tabs. In tab “Radiation sources“ there are names and input data concerning each operating frequency. On this page, one can choose the antenna system radiation pattern. If the blank field is chosen, then the HRP and VRP for each observation point have to be introduced manually. If there
35、 is Rec. ITU-T K.70 (2007)/Amd.4 (12/2014) 3 no information available concerning the transmitting radiation pattern, the “isotropic“ radiation pattern may be used, but this will lead to an overestimation of the field, growing with the antenna gain. It is also possible to choose the 3D radiation patt
36、ern. Figure I.2 Main screen of the EMF-estimator with “Radiating sources“ tab opened Tab “Source XXX“ (Figure I.4) shows the results of calculations for the XXX source of radiation (operating frequency). There is also a button on this screen, allowing for the visualization of the distribution of the
37、 equivalent plane-wave power density, produced at a chosen operating frequency, as a function of the distance along an observation line defined by the user. The “Antenna orientation and calculations“ Tab (Figure I.3) is designed to input the location of each transmitting antenna and the parameters o
38、f the user-defined observation points line. The data has to be written down in the respective blank spaces. In the main toolbar, there are inputs to options such as: open/save project, import new radiation pattern, add/remove sources, print, chart with the ICNIRP reference limits and cumulative expo
39、sure, which makes possible the calculation of the cumulative exposure for all the sources introduced in the project (see in main toolbar). 4 Rec. ITU-T K.70 (2007)/Amd.4 (12/2014) Figure I.3 Screen of the EMF-estimator with “Antenna orientation and calculations“ tab opened Figure I.4 Screen of the E
40、MF-estimator with “Source XXX“ tab opened Rec. ITU-T K.70 (2007)/Amd.4 (12/2014) 5 Figure I.5 Screen of the EMF-estimator the results of the cumulative exposure calculations It should be noted that the results of calculations are strongly affected by the exactness of the input data and all the limit
41、ations of the model. Since the radiation patterns are given on the one degree lattice then, for very high gain antennas, the curves may not be smooth because, for quickly varying functions, one degree step can be too big. I.4 Compliance distances Tab “Source XXX“ also presents the results of the cal
42、culation of the compliance distances. If the distance is greater than 0.6*D2/ then the results are shown. If it is smaller, then the overestimating value is shown, i.e., the lower value of the two: at the distances 0.6*D2/ and at distance at which the radiation limit is achieved under the assumption
43、 of isotropic radiation pattern (f(,) = 1). It should be noted that, in some cases, such an overestimation may be quite big. I.5 Coefficient concerning transmitter power An additional explanation is needed for the parameter “Type of service coefficient nominal/mean transmitter power“. This parameter
44、 is required because in many cases the nominal (rated) transmitter power (known for the user) is different from the mean transmitter power (required in the formula for the rms electric field strength calculation). After choosing the type of service, the nominal transmitter power will be automaticall
45、y multiplied by a suitable coefficient. Table B.1 contains the coefficients for the most commonly used types of radiocommunication services. I.6 Library radiation patterns of the antenna systems In the folder “Library“, the files containing radiation patterns for some typical antenna systems used in
46、 radiocommunication and broadcasting are collected. There are patterns for FM, TV VHF, TV UHF, GSM 900, GSM 1800, AM and radio relay link antennas. Of course, this library contains only the 6 Rec. ITU-T K.70 (2007)/Amd.4 (12/2014) samples of possible configurations of antennas and antenna systems th
47、at are in use worldwide. It should be noted that each broadcasting antenna is individually designed and there are no two identical systems. However, the antennas included in the library represent typical solutions realized in many telecommunication systems. There is also a subfolder “User input temp
48、lates“ containing “User_2D_Import_Radiation _Pattern.csv“ and “User_3D_Import _Radiation _Pattern.csv“ files, in a format which enables importing user data for any additional antenna, by using the import option of the EMF-estimator. Such files may then be added to the library and used in the calcula
49、tions. I.7 Examples of calculations The folder “Examples“ contain the projects with results of calculations presented in this Recommendation. It is possible to open any project and to follow the respective calculations. It is also possible to introduce changes, in order to observe their influence on the results. I.8 Additional comments a) The minimum input data required for the electric field strength calculations are the values of EIRP (or ERP), operating frequency, size of the a
