1、 ETSI TR 102 581 V1.2.1 (2015-11) Speech Processing, Transmission and Quality Aspects (STQ); A Study on the Minimum Additional Required Attenuation on the Antenna Path of the Field Test Equipment TECHNICAL REPORT ETSI ETSI TR 102 581 V1.2.1 (2015-11) 2 Reference RTR/STQ-00200m Keywords 3G, antenna,
2、GSM, MIMO, network ETSI 650 Route des Lucioles F-06921 Sophia Antipolis Cedex - FRANCE Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16 Siret N 348 623 562 00017 - NAF 742 C Association but non lucratif enregistre la Sous-Prfecture de Grasse (06) N 7803/88 Important notice The present document can be
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7、en authorization of ETSI. The copyright and the foregoing restriction extend to reproduction in all media. European Telecommunications Standards Institute 2015. All rights reserved. DECTTM, PLUGTESTSTM, UMTSTMand the ETSI logo are Trade Marks of ETSI registered for the benefit of its Members. 3GPPTM
8、 and LTE are Trade Marks of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners. GSM and the GSM logo are Trade Marks registered and owned by the GSM Association. ETSI ETSI TR 102 581 V1.2.1 (2015-11) 3 Contents Intellectual Property Rights 4g3Foreword . 4g3Modal v
9、erbs terminology 4g31 Scope 5g32 References 5g32.1 Normative references . 5g32.2 Informative references 5g33 Abbreviations . 5g34 Typical measurement scenario . 6g35 Real life scenario versus measurement scenario 6g35.1 Introduction 6g35.2 Case 1 of the Measurement Scenario . 7g35.3 Case 2 of the Me
10、asurement Scenario . 7g36 Estimation of additional required attenuation based on the measurement model 8g37 Generally recommended additional attenuation values 10g38 Conclusions 11g3Annex A: In car simulation test 12g3A.1 Introduction 12g3A.2 Problem definition 12g3A.3 Test set up . 12g3A.4 Test des
11、cription 12g3A.5 Results 12g3Annex B: In car simulation test in MIMO environment 14g3B.1 Introduction 14g3B.2 Problem definition 14g3B.3 Test set up . 14g3B.4 Test description 14g3B.5 Results 14g3Annex A (informative): Bibliography . 17g3History 18g3ETSI ETSI TR 102 581 V1.2.1 (2015-11) 4 Intellectu
12、al Property Rights IPRs essential or potentially essential to the present document may have been declared to ETSI. The information pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found in ETSI SR 000 314: “Intellectual Property Rights (I
13、PRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of ETSI standards“, which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web server (http:/ipr.etsi.org). Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been
14、carried out by ETSI. No guarantee can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web server) which are, or may be, or may become, essential to the present document. Foreword This Technical Report (TR) has been produced by ETSI Technical C
15、ommittee Speech and multimedia Transmission Quality (STQ). Modal verbs terminology In the present document “shall“, “shall not“, “should“, “should not“, “may“, “need not“, “will“, “will not“, “can“ and “cannot“ are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms
16、 for the expression of provisions). “must“ and “must not“ are NOT allowed in ETSI deliverables except when used in direct citation. ETSI ETSI TR 102 581 V1.2.1 (2015-11) 5 1 Scope The present document presents a theoretical model to be used for the estimation of the minimum required additional atten
17、uation on the antenna path of the field test equipment in order for this to emulate the real life scenarios. The model takes into consideration propagation within different environments, such as dense or spread urban areas, as well as in car and pedestrian scenarios. In addition, in order to provide
18、 the estimator, the model uses previously determined and known values for a set of parameters such as measurement and phone antenna gain, cable loss, car penetration, body loss. The model is not applicable in the HSPA environments requiring MIMO technology and in the LTE environment. 2 References 2.
19、1 Normative references References are either specific (identified by date of publication and/or edition number or version number) or non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the reference document (including any amendme
20、nts) applies. Referenced documents which are not found to be publicly available in the expected location might be found at http:/docbox.etsi.org/Reference. NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee their long term validity. The fo
21、llowing referenced documents are necessary for the application of the present document. Not applicable. 2.2 Informative references References are either specific (identified by date of publication and/or edition number or version number) or non-specific. For specific references, only the cited versi
22、on applies. For non-specific references, the latest version of the reference document (including any amendments) applies. NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee their long term validity. The following referenced documents are n
23、ot necessary for the application of the present document but they assist the user with regard to a particular subject area. 3 Abbreviations For the purposes of the present document, the following abbreviations apply: CDMA Code Division Multiple Access HSPA High Speed Packet Access LTE Long Term Evol
24、ution ME Measurement Equipment MIMO Multiple Input Multiple Output PCS Personal Communication System RF Radio Frequency RSSI Received Signal Strength Indicator ETSI ETSI TR 102 581 V1.2.1 (2015-11) 6 4 Typical measurement scenario To ensure accurate network monitoring and testing, the field equipmen
25、t needs to be set up to emulate real-life mobile phone utilization scenarios as closely as possible. The complexity of this emulation increases with the number of elements present in the mobile phone antennas which use e.g. dual-polarized MIMO and automatic band switching techniques or other smart f
26、unctions. Generally, non-MIMO equipment uses a single external antenna mounted on the roof of the drive test vehicle. This external antenna is connected to the RF input of the equipment box, which then connects to the RF input of the phone that is found inside the equipment box (see figure 4.1). Fig
27、ure 4.1: Measurement equipment This set-up is beneficial to the signal strength (the RF power) that the phone receives and generates more optimistic results than a normal subscriber would experience. Therefore, an additional attenuator, characterized by the appropriate attenuation value, is required
28、 to ensure that the measurement configuration reproduces as closely as possible the real-life scenario. It should be noted, however, that there are a set of RF and electrical components involved in the measurements that compensate for the measurements imperfections to a certain extent. This is why a
29、 proper measurement set up requires the evaluation of the impact of these components (such as measurement antenna gain, cable loss, phone antenna gain, car penetration, and body loss) in order to estimate the minimum required additional attenuation to be inserted on the measurement path. 5 Real life
30、 scenario versus measurement scenario 5.1 Introduction While the values of the RF and electrical characteristics are generally specified by the manufacturers of the measurement equipments parts, the required additional attenuation value needs to be determined based on a measurement model designed to
31、 best emulate the real-life scenario. The model is based on the required equivalency between the real-life conditions and the measurement scenarios. ETSI ETSI TR 102 581 V1.2.1 (2015-11) 7 In a real-life scenario, which considers a subscriber using the phone inside the car, the power received by the
32、 phones antenna is given by equation (1) below: Pin,phone = Prf 1 + Atten(car) + Atten(human head) + Gain(antenna phone) dB (1) where Prf1 is the RF power at the phones location. The power is dependent on the path loss of the RF signal. The path loss depends on a set of environmental factors (such a
33、s the nature of the landscape, the type and the morphology of the measurement location, the geography of the location) described by the function F and the receiving antennas height h (see equation (2) below): PathLoss(h) = F(landscape, morphology, geography) + A(h) dB (2) The A(h) factor is also cal
34、led the correction factor and an approximate value of this factor can be calculated using Hattas equation for dense cities covered by micro cells with a small radius (about 1km) (see equation (3) below): A (h) = (1,1 lg (f) -0,7) h -1,56 lg (f) + 0,8 dB (3) where f(MHz) represents the carrier freque
35、ncy. For spread cities covered by macro cells with radius larger than 1 km, the A(h) does not depend on the frequency anymore (see equation (4) below): A (h) = 3,2 (lg (11,75 h)2 - 4,97 dB (4) In the measurements scenario, the received power by the phone comes through the external antenna mounted on
36、 the drive test vehicles roof and is given by (equation (5) below): Pin,phone = Prf 2 + Gain(external antenna) + Atten(ext antenna cable) + Atten(ME) + Atten(add atten) dB (5) where Prf2 represents the RF power at the external antenna location, and the measurement equipment is denoted ME. The term A
37、tten(ME) denotes the attenuation inserted by the path between the RF input of the ME box to the RF input of the phone, and includes connectors and cable loss. The measurement scenario emulates the real-life condition if the Pin,phone given in the both scenarios is the same. The term Atten(add atten)
38、 represents the attenuation that is required in the measurement chain in order to ensure that the measurement scenario emulates the real live scenario. 5.2 Case 1 of the Measurement Scenario If the measurements are performed using a car, then the antenna height is considered to be 1,5 meters and the
39、 equality 6 (6) takes place: Prf1 = Prf2 (6) The value of the required additional attenuation can be therefore calculated using equations (1) and (5) and the equality (6) (see equation (7) below): Atten(add atten) = - Gain(external antenna) - Atten(ext antenna cable) - Atten(ME) + Atten(car) + Atten
40、human head) + Gain(antenna phone) (7) 5.3 Case 2 of the Measurement Scenario If the measurements are performed using a van, mini truck, or bus, then the antenna is higher than 1,5 meters. Assuming that the environmental factors remain unchanged and using equation (2), the following equality (8), ta
41、kes place. Prf2 = Prf1 + PathLoss(h) - PathLoss(1,5 m) = Prf1 + (A(h) - A(1,5 m) (8) The equation (8) is equivalent to a correction of the external antenna gain as it is described by equation (9), below: Gain(external antenna)_corrected = Gain(external antenna) + (A(h) - A(1,5 m) (9) Using the equat
42、ion of the external antenna gain (9), the value of the required additional attenuation (7) becomes equation (10), below: Atten(add atten) = -Gain(external antenna) - (A(h) - A(1,5 m) - Atten(ext antenna cable) - Atten(ME) + Atten(car) + Atten(human head) + Gain(antenna phone) (10) ETSI ETSI TR 102 5
43、81 V1.2.1 (2015-11) 8 The equation (10) gives the estimated additional attenuation value that needs to be inserted in the measurement configuration chain in order to ensure the equivalency between the subscribers and the measurement scenario. This allows the networks performance to be evaluated and
44、monitored from the subscribers point of view. 6 Estimation of additional required attenuation based on the measurement model Specific values for the electrical and RF characteristics of the field test equipments components are generally available from the component manufactures, as it is the case of
45、 external antenna gain, phone antenna gain and cable loss. In the case of characteristics such as body loss and attenuation generated by the equipment itself (connectors and cable), the values are estimated by special designed tests and measurements. The electrical and RF characteristics exhibit spe
46、cific dependencies on the frequency. Thus, only average values or a range of values can be provided. Table 6.1 presents the average values of the RF and electrical characteristics of the measurement equipments components. Table 6.1: RF and electrical characteristics of the measurement equipment Atte
47、n(car) or car penetration Atten(human head) or body loss Gain (phone antenna) Gain (external antenna) + Atten(ext antenna cable) Atten(ME including cables, connectors) 5 dB See note 1. 3 dB See note 2. 1 dBi See note 3. 3 dBi See note 4. 1 dB See note 5. NOTE 1: Usual average value across different
48、types of cars. NOTE 2: Average value known from published results of different tests (RADCOM, VERIZON tests, Test Forum of CDMA Development Group 2004). NOTE 3: Average value, but it depends on the phones type. Differences between phones might reach up to 3 dB. NOTE 4: Average value (see antenna spe
49、cs such as the MaxRad combo). NOTE 5: Average value obtained from a set of measurements on the ME. Based on the values presented in table 6.1 and the model presented in the clause 5.3, equation (10), the minimum required attenuation value can be determined for different antenna heights, frequencies and environments. Table 6.2 presents these attenuation values (including the attenuation of the antenna cable). ETSI ETSI TR 102 581 V1.2.1 (2015-11) 9 Table 6.2: Models results for the minimum required attenuation in different scenarios Envir
