1、 International Telecommunication Union ITU-T K.49TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (12/2005) SERIES K: PROTECTION AGAINST INTERFERENCE Test requirements and performance criteria for voice terminal telephones subject to disturbance from digital mobile telecommunications systems ITU-T Re
2、commendation K.49 ITU-T Rec. K.49 (12/2005) i ITU-T Recommendation K.49 Test requirements and performance criteria for voice terminal telephones subject to disturbance from digital mobile telecommunications systems Summary This Recommendation specifies the test set-up, the test levels and the perfor
3、mance criteria to verify the immunity of voice terminal telephones to disturbance from digital mobile telecommunications systems. Source ITU-T Recommendation K.49 was approved on 16 December 2005 by ITU-T Study Group 5 (2005-2008) under the ITU-T Recommendation A.8 procedure. ii ITU-T Rec. K.49 (12/
4、2005) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff question
5、s 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 study groups which, in turn, produce Recommendations on
6、 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 with ISO and IEC. NOTE In this Recommendation, the
7、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 provisions (to ensure e.g. interoperability or applic
8、ability) 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 of such words does not suggest that compliance with th
9、e Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU 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 position concerning the evidence, validity or applicabi
10、lity 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, protected by patents, which may be required to implement
11、 this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. ITU 2006 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior wr
12、itten permission of ITU. ITU-T Rec. K.49 (12/2005) iii CONTENTS Page 1 Scope 1 2 References. 1 3 Definitions 1 4 Abbreviations 2 5 Introduction 2 5.1 General considerations . 2 5.2 Disturbance from mobile handsets . 2 5.3 Disturbance from base stations. 3 6 Calculation of disturbance 4 6.1 Level of
13、disturbance . 4 7 Test set-up. 5 7.1 General configuration. 5 8 Test levels . 7 9 Performance criteria 7 9.1 Base station disturbance performance criteria A 7 9.2 Mobile handset disturbance performance criteria B. 8 Appendix I Example of mobile systems characteristics . 9 I.1 General considerations
14、. 9 I.2 Mobile handset characteristics . 9 I.3 Base station characteristics. 10 I.4 Level of disturbance . 10 BIBLIOGRAPHY 11 ITU-T Rec. K.49 (12/2005) 1 ITU-T Recommendation K.49 Test requirements and performance criteria for voice terminal telephones subject to disturbance from digital mobile tele
15、communications systems 1 Scope The scope of this Recommendation is to define the test level and the test methods to establish the grade of immunity of voice terminal telephones to radio disturbance generated by equipment used in digital mobile telecommunications systems. This Recommendation consider
16、s as disturbance the radio-frequency signal generated by both the base station and the mobile handset of digital mobile telecommunications systems. This Recommendation establishes an adequate level of protection of voice terminal telephones to the disturbance produced by the digital mobile telecommu
17、nications systems; the level of protection defined in this Recommendation is adequate for a normal environment in which a radio field generated by a base station is present and also some mobile handsets are in function (switched on). This Recommendation is applicable to both residential and commerci
18、al environments. The interference derived from analogue mobile telecommunications systems is not considered in this Recommendation. Conformance to this Recommendation does not imply immunity of voice terminal telephones to high levels of disturbance derived from the mobile telecommunications network
19、; for example, the proximity of a base station at less than 10 metres. 2 References The 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
20、 valid. All Recommendations and other references are subject to revision; users of this 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 Recommendat
21、ions is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. 1 IEC 60050-161 (1990), International electrotechnical vocabulary. Chapter 161: Electromagnetic compatibility. 2 IEC 61000-4-3 (2006), Elec
22、tromagnetic compatibility (EMC) Part 4-3: Testing and measurement techniques Radiated, radio-frequency, electromagnetic field immunity test. 3 ITU-T Recommendation P.57 (2005), Artificial ears. 3 Definitions This Recommendation uses the definitions contained in the publication IEC 60050-161 1. Addit
23、ional definitions are: 3.1 mobile handset: Not fixed terminal equipment used for data or voice communication and connected to a fixed telecommunications network via radio interface. 3.2 base station: Fixed radio installation of a mobile network. 3.3 active mode: State of a mobile handset when switch
24、ed on and connected to the radio network to establish an exchange of user information (voice or data), also defined as traffic mode. 2 ITU-T Rec. K.49 (12/2005) 3.4 idle mode: State of a mobile handset when switched on but with no connection to the radio network in order to establish an exchange of
25、user information (voice or data). 3.5 voice terminal telephone: Voice terminal equipment of a telecommunications network; this definition covers the normal analogue telephones used in a PSTN network, the digital telephones used in an ISDN network and all types of terminal equipment attached to a wir
26、ed telecommunications network having a voice interface. 4 Abbreviations This Recommendation uses the following abbreviations: AM Amplitude Modulation CDMA Code Division Multiple Access ERP Effective Radiated Power EUT Equipment Under Test ISDN Integrated Services Digital Network PSTN Public Switched
27、 Telecommunications Network RF Radio Frequency SPL Sound Pressure Level TDMA Time Division Multiple Access 5 Introduction 5.1 General considerations The possible sources of radio disturbance considered here are the radio frequency signals emitted from the following systems: mobile handsets; base sta
28、tion equipment. Mobile handsets are an example of radio equipment working using a shared radio resource. The possible alternative solutions used to share the radio resources are based on division multiple access technology. In the mobile system the methods used are: FDMA, CDMA, TDMA or mixed technol
29、ogies. All these types of technologies present solutions with burst transmission. The voice terminal telephone is influenced by the burst transmission of the mobile telephone. This burst transmission may be comparable to a 100% amplitude modulated RF envelope. The voice terminal telephone having som
30、e non-linear component is able to demodulate this envelope and convert it into the audiofrequency band. For this reason the voice terminal telephone will be subject to interference in the audio passband since the frame and burst rates of mobile telephone are in the range 50 to 200 Hz. The following
31、subclauses consider the interference derived from mobile handsets and base stations. 5.2 Disturbance from mobile handsets In an office or commercial environment, there is a possibility to have one or more types of mobile handsets. ITU-T Rec. K.49 (12/2005) 3 During the study of disturbance levels, i
32、t is necessary to consider the various elements that could influence the level of the interfering signal. The level of emission of a mobile handset depends on the location in which the communication is activated due to the following technical considerations. Some types of mobile handset include a sy
33、stem to regulate the level of power transmission. The level of power depends on the level of the received signal; this is influenced by the distance between the mobile handset and the base station and also by the path attenuation of the radio signal. From this point, considering the same distance be
34、tween a mobile handset and a base station, the higher emission level is present in the indoor environment; this is due to the attenuation of the radio signal caused by the building structure. Another factor that influences the level of power emitted is the condition of the mobile handset: idle mode
35、(waiting for a call) or active mode (conversation). Normally, a mobile handset emits very low radio-frequency power when there is no active communication (idle mode); when there is a telephone communication the level of emission is relatively high (active mode). It is likely that, in normal situatio
36、ns, the proportion of time that the mobile handset is in transmission is lower than the proportion of time that the mobile handset is in the idle mode. Following the explanation above, the worst case for this particular type of disturbance is when a mobile handset is in the active mode in an office
37、or in a similar indoor environment. This Recommendation considers the case in which some mobile handsets are in a building in the same room near a voice terminal telephone, but not used for a telephone conversation at the same time as the voice terminal telephone. The probability of having more than
38、 one conversation active at the same time in a room is considered to be lower. 5.3 Disturbance from base stations The base stations of a mobile network are normally located outside a building or on the top of the building itself. This type of transmitter is characterized by: continuous transmission;
39、 longer distance from the transmitter to voice terminal telephone (i.e., greater than 10 metres). In this case, it must be considered that the building structure produces radio-frequency attenuation to the signal coming from the base station and this type of attenuation is normally considered to be
40、about 10 dB. It is necessary to consider that the vertical radiation pattern from a typical base station antenna introduces an attenuation (at 60 degrees or greater from the main lobe) of between 20 dB and 50 dB. Base station antennas situated on the top of the building are tower-mounted. In this ca
41、se, the angle between the antenna main lobe and the offices in the building below (separation angle in Figure 1) is greater than 60 degrees, so this 20 dB of attenuation can be considered in the calculation of power disturbance. 4 ITU-T Rec. K.49 (12/2005) Figure 1/K.49 Base station separation angle
42、 6 Calculation of disturbance The power level of the source and the distance from a specific point to the source determine the level of possible radio signal disturbance at that point. The frequency of the signal does not influence the level of the disturbance at short distance from the source. The
43、transmitted power of radio transmitters is often specified in terms of ERP. The field strength generated from a transmitter in the far field can be directly obtained by the following formula: dPkE = where: E is the field strength, in V/m k is a constant; for free space is equal to 7 P is the ERP, in
44、 Watts d is the distance from the source to the point in which the field is calculated in metres 6.1 Level of disturbance 6.1.1 Base station disturbance This Recommendation considers a room situated at the top floor of a building with a base station located on the top of the same building, as report
45、ed in Figure 1. This is the worst situation for disturbance generated by base station equipment. The distance between the voice terminal telephone and the base station is considered equal to 10 metres. In this situation, in the room the level of signal disturbance is lower than 3 V/m (value derived
46、considering a transmitted power of 200 W and only an attenuation of the building of 10 dB); the reduction due to the radiation pattern of the antenna is not considered. This level of disturbance is a disturbance signal present in the room without any interruption (continuous disturbance). 6.1.2 Mobi
47、le telephone disturbance The majority of mobile handsets actually used in mobile networks have a maximum power of 2 W; mobile handsets with a greater power are used only by service personnel for maintenance purposes. ITU-T Rec. K.49 (12/2005) 5 In the case where a mobile handset is located in a room
48、, the transmitted power of the mobile handset is 2 W and the distance from the mobile telephone to the voice terminal telephone is 1 metre, and when the mobile handset is in active mode, the level of signal disturbance is about 10 V/m. This level of disturbance is not a constant disturbance signal,
49、always present in the room, but it is present only for a short period when the handset is in the active mode. 7 Test set-up 7.1 General configuration The definition of test sites, the calibration of the field and the test procedure shall be in accordance with the basic standard IEC 61000-4-3 2 with the following modifications. The analogue voice terminal telephone under test, EUT, is located in the test facility in accordance with IEC 61000-4-3 on a non-conductive table higher than 0.8 metres. The installation of the EUT in the test facilities should be a good repr
