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.122 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (12/2016) SERIES K: PROTECTION AGAINST INTERFERENCE Exposure levels in close proximity of radiocommunication antennas Recommendation ITU-T K.122 Rec. ITU-T K.122 (12/201
2、6) i Recommendation ITU-T K.122 Exposure levels in close proximity of radiocommunication antennas Summary The guidance concerning the exposure levels in close proximity to transmitting antennas is important for safety of the radiocommunication staff operating in such areas. Recommendation ITU-T K.12
3、2 gives information concerning the electric field strength levels that can be expected in close proximity to the broadcasting and radiocommunication antennas so that a comparison with the exposure limits is possible. This is important for maintenance personnel and in some cases also for the general
4、public. In the case of workers it is recommended that affected personnel should be trained by expert staff so that they are able to assess the exposure levels in close proximity of radiocommunication antennas. There are many possible configurations of transmitting antennas. In this Recommendation th
5、e most typical ones are presented, in order to give general information about exposure levels that can be expected during the operation of radiocommunication systems. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T K.122 2016-12-14 5 11.1002/1000/13138 Keywords Exposure leve
6、l, maintenance, occupational exposure, radiocommunication antenna. * To access the Recommendation, type the URL http:/handle.itu.int/ in the address field of your web browser, followed by the Recommendations unique ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T K.122 (12/
7、2016) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible fo
8、r studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T stud
9、y groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis
10、with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory pr
11、ovisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents are used to express requirements. The use o
12、f such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTSITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no pos
13、ition concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, prot
14、ected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2017 All rights reserved. No part
15、of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T K.122 (12/2016) iii Table of Contents Page 1 Scope . 1 2 References . 1 3 Definitions 2 3.1 Terms defined elsewhere 2 3.2 Terms defined in this Recommendation . 5 4 Abbreviations a
16、nd acronyms 6 5 Conventions 6 6 FM broadcasting antenna with horizontal polarization 6 6.1 Total exposure 13 7 FM broadcasting antenna with vertical polarization 15 7.1 Total exposure 21 8 UHF TV/DVB-T antenna . 23 8.1 Total exposure 31 8.2 UHF TV system with vertical polarization 31 9 Mobile commun
17、ication dual-band 900/1 800 MHz antenna panel 33 9.1 Frequency 947.5 MHz 36 9.2 Frequency 1 842.5 MHz . 40 9.3 Total exposure in both frequency bands . 44 10 Microcell ceiling-mounted antenna 45 10.1 Total exposure 50 11 Fixed point-to-point 22.4 GHz antenna 51 12 Fixed point-to-point 75 GHz antenna
18、 . 56 13 Total exposure 58 14 Exposure levels for different transmitter power . 58 15 Conclusions. 59 Bibliography. 61 iv Rec. ITU-T K.122 (12/2016) Introduction This Recommendation provides information on the electric field strength levels that could be expected in close proximity to broadcasting a
19、nd radiocommunication antennas so that a comparison with the exposure limits is possible. This is important for maintenance personnel and in some cases also for the general public. This Recommendation presents examples of the results of calculations done for typical conditions of operation of radio
20、equipment in areas accessible by maintenance personnel or in some cases for the general public. This Recommendation also gives guidance on how to recalculate these levels for user-specific configurations. The results presented in this Recommendation have been obtained using the following calculation
21、 methods: method of moments (MoM) or hybrid methods multilevel fast multipole method (MLFMM) and physical optics with MoM (PO/MoM). All these methods are full-wave methods so they allow for calculations even in the reactive part of the near-field region. Rec. ITU-T K.122 (12/2016) 1 Recommendation I
22、TU-T K.122 Exposure levels in close proximity of radiocommunication antennas 1 Scope In this Recommendation the level of electric field strength is simulated in the vicinity of transmitting antennas of the: FM high-power antenna system with horizontal polarization FM high-power antenna system with v
23、ertical polarization UHF TV high-power antenna system with horizontal polarization mobile communication dual-band 900 /1 800MHz antenna panel (+45/45 polarization) micro-cell ceiling-mounted antenna fixed point-to-point 22.4 GHz antenna fixed point-to-point 75 GHz antenna. There are many possible co
24、nfigurations of transmitting antennas. In this Recommendation most typical ones are presented in order to give information about exposure levels that may be expected during the operation of radiocommunication systems. It is also recommended, if the exposure level is close to the limit, to confirm re
25、sults by measurements using the procedures defined in ITU-T K.61 and IEC 62232. NOTE In addition to the field levels provided in this Recommendation, guidelines about how to manage workers exposure in the vicinity of base stations can be found in ETSI 101870, b-EN 50499 and IEC 62232. 2 References T
26、he following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of th
27、is Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation d
28、oes not give it, as a stand-alone document, the status of a Recommendation. ITU-T K.52 Recommendation ITU-T K.52 (2004), Guidance on complying with limits for human exposure to electromagnetic fields. ITU-T K.61 Recommendation ITU-T K.61 (2003), Guidance to measurement and numerical prediction of el
29、ectromagnetic fields for compliance with human exposure limits for telecommunication installations. ITU-T K.70 Recommendation ITU-T K.70 (2007), Mitigation techniques to limit human exposure to EMFs in the vicinity of radiocommunication stations. ITU-T K.91 Recommendation ITU-T K.91 (2012), Guidance
30、 for assessment, evaluation and monitoring of human exposure to radio frequency electromagnetic fields. ITU-R BS.1195 Recommendation ITU-R BS.1195 (1995), Transmitting antenna characteristics at VHF and UHF. 2 Rec. ITU-T K.122 (12/2016) ITU-R BS.1698 Recommendation ITU-R BS.1698 (2005), Evaluating f
31、ields from terrestrial broadcasting transmitting systems operating in any frequency band for assessing exposure to non-ionizing radiation. ICNIRP ICNIRP (1998), ICNIRP Guidelines for Limiting Exposure to Time-Varying Electric, Magnetic and Electromagnetic Fields (up to 300 GHz), Health Physics, Vol.
32、 74, No. 4; pp. 494-522. IEC 62232 IEC 62232 (2011), Determination of RF field strength and SAR in the vicinity of radiocommunication base stations for the purpose of evaluating human exposure. IEEE C95.1 IEEE C95.1-2005, Standard for Safety Levels with Respect to Human Exposure to Radio Frequency E
33、lectromagnetic Fields, 3 kHz to 300 GHz. IEEE C95.7 IEEE C95.7-2005, Recommended Practice for Radio Frequency Safety Programs, 3 kHz to 300 GHz. ISO/IEC 98-3 ISO/IEC Guide 98-3:2008, Uncertainty of measurement Part 3: Guide to the expression of uncertainty in measurement (GUM:1995). ETSI 101870 ETSI
34、 TR 101 870 V1.1.1 (2001-11), Fixed radio transmitter sites; Exposure to non-ionising electromagnetic fields; Guidelines for working conditions. ETSI 102457 ETSI TR 102 457 V1.1.1 (2006-08), Transmission and Multiplexing (TM); Study on the electromagnetic radiated field in fixed radio systems for en
35、vironmental issues. 3 Definitions 3.1 Terms defined elsewhere This Recommendation uses the following terms defined elsewhere: 3.1.1 antenna ITU-T K.70: Device that serves as a transducer between a guided wave (e.g., coaxial cable) and a free space wave, or vice versa. It can be used to emit or recei
36、ve a radio signal. In this Recommendation the term antenna is used only for emitting antenna(s). 3.1.2 antenna gain ITU-T K.70: The antenna gain G (, ) is the ratio of power radiated per unit solid angle multiplied by 4 to the total input power. The gain is frequently expressed in decibels with resp
37、ect to an isotropic antenna (dBi). The formula defining the gain is: ddPPG rini 4),(Rec. ITU-T K.122 (12/2016) 3 where: , are the angles in polar coordinates system is the antenna efficiency due to dissipative losses Pr is the radiated power in the (, ) direction Pin is the total input power d an el
38、ementary solid angle in the direction of observation. NOTE In manufacturers catalogues the antenna gain is understood as a maximum value of the antenna gain. Gain does not include losses arising from impedance and polarization mismatches. If an antenna is without dissipative loss then its gain is eq
39、ual to its directivity D (, ). 3.1.3 average (temporal) power (Pavg) ITU-T K.52: The time-averaged rate of energy transfer defined by: where: P(t) is the instantaneous power, t1 and t2 are the start and stop time of the exposure. 3.1.4 basic restrictions ITU-T K.70: Restrictions on exposure to time-
40、varying electric, magnetic and electromagnetic fields that are based directly on established health effects. Depending upon the frequency of the field, the physical quantities used to specify these restrictions are: current density (J), specific absorption rate (SAR) and power density (S). 3.1.5 com
41、pliance distance ITU-T K.70: Minimum distance from the antenna to the point of investigation where the field level is deemed to be compliant with the limits. 3.1.6 controlled/occupational exposure ITU-T K.70: Controlled/occupational exposure applies to situations where the persons are exposed as a c
42、onsequence of their employment and in which those persons who are exposed have been made fully aware of the potential for exposure and can exercise control over their exposure. Controlled/occupational exposure also applies to the cases where the exposure is of transient nature as a result of inciden
43、tal passage through a location where the exposure limits may be above the general population/uncontrolled environment limits, as long as the exposed person has been made fully aware of the potential for exposure and can exercise control over his or her exposure by leaving the area or by some other a
44、ppropriate means. 3.1.7 directivity ITU-T K.70: Is the ratio of the power radiated per unit solid angle over the average power radiated per unit solid angle. 3.1.8 equivalent isotropically radiated power (eirp) ITU-T K.70: The EIRP is the product of the power supplied to the antenna and the maximum
45、antenna gain relative to an isotropic antenna. 3.1.9 equivalent radiated power (ERP) ITU-T K.70: The ERP is the product of the power supplied to the antenna and the maximum antenna gain relative to a half-wave dipole antenna. 3.1.10 exposure ITU-T K.52: Exposure occurs wherever a person is subjected
46、 to electric, magnetic or electromagnetic fields or to contact currents other than those originating from physiological processes in the body or other natural phenomena. 3.1.11 exposure level ITU-T K.52: Exposure level is the value of the quantity used when a person is exposed to electromagnetic fie
47、lds or contact currents. 21 )(1 12 tta vg dttPttP4 Rec. ITU-T K.122 (12/2016) 3.1.12 exposure limits ITU-T K.70: Values of the basic restrictions or reference levels acknowledged, according to obligatory regulations, as the limits for the permissible maximum level of the human exposure to the electr
48、omagnetic fields. 3.1.13 far-field region ITU-T K.52: That region of the field of an antenna where the angular field distribution is essentially independent of the distance from the antenna. In the far-field region, the field has predominantly plane-wave character, i.e., locally uniform distribution
49、 of electric field strength and magnetic field strength in planes transverse to the direction of propagation. 3.1.14 general population/uncontrolled exposure ITU-T K.52: General population/uncontrolled exposure applies to situations in which the general public may be exposed or in which persons who are exposed as a consequence of their employment may not be made fully aware of the potential for exposure or cannot exercise control over their exposure. 3.1.15
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