1、 Recommendation ITU-R P.2109-0 (06/2017) Prediction of building entry loss P Series Radiowave propagation ii Rec. ITU-R P.2109-0 Foreword The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient and economical use of the radio-frequency spectrum by all radiocommunica
2、tion services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. The regulatory and policy functions of the Radiocommunication Sector are performed by World and Regional Radiocommunication Conferences and Radiocomm
3、unication Assemblies supported by Study Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is described in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC referenced in Annex 1 of Resolution ITU-R 1. Forms to be used for the submission of patent statements and licensing declara
4、tions by patent holders are available from http:/www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of the Common Patent Policy for ITU-T/ITU-R/ISO/IEC and the ITU-R patent information database can also be found. Series of ITU-R Recommendations (Also available online at http:/ww
5、w.itu.int/publ/R-REC/en) Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for television BS Broadcasting service (sound) BT Broadcasting service (television) F Fixed service M Mobile, radiodetermination, amateur and related satellite services P Radiowave pr
6、opagation RA Radio astronomy RS Remote sensing systems S Fixed-satellite service SA Space applications and meteorology SF Frequency sharing and coordination between fixed-satellite and fixed service systems SM Spectrum management SNG Satellite news gathering TF Time signals and frequency standards e
7、missions V Vocabulary and related subjects Note: This ITU-R Recommendation was approved in English under the procedure detailed in Resolution ITU-R 1. Electronic Publication Geneva, 2017 ITU 2017 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without wri
8、tten permission of ITU. Rec. ITU-R P.2109-0 1 RECOMMENDATION ITU-R P.2109-0 Prediction of building entry loss (2017) Scope This Recommendation provides a method for estimating building entry loss at frequencies between about 80 MHz and 100 GHz. The method is not site-specific, and is primarily inten
9、ded for use in sharing and compatibility studies. Keywords Building, indoor, propagation, interference, entry The ITU Radiocommunication Assembly, considering a) that, for system planning and interference assessment it may be necessary to account for the attenuation suffered by radio waves in passin
10、g into, or out of, buildings; b) that there is a need to give guidance to engineers to estimate coverage or predict interference from outdoor to indoor and indoor to outdoor systems, recognizing a) that Recommendation ITU-R P.2040 provides guidance on the effect of building materials and structures
11、on radio waves; b) that Report ITU-R P.2346 contains collated empirical data on building entry loss, recommends that the model in Annex 1 be used to estimate building entry loss. Annex 1 1 Introduction This Annex provides a model for building entry loss, as defined in Recommendation ITU-R P.2040. Th
12、e output of the model is in the form of a cumulative distribution function of the probability that a given loss will not be exceeded. The model makes no attempt to separate the loss suffered by a signal penetrating the exterior wall and the attenuation suffered in the path through the building. This
13、 approach has been adopted as it is felt unlikely that, in the context of ITU-R studies, sufficiently detailed building-specific information would be available. Building entry loss exhibits great variability, both within any given building and between different buildings. Although techniques such as
14、 ray-tracing can provide useful site-specific predictions when coupled with detailed architectural data, such models will usually be inappropriate for generic applications such as spectrum sharing studies. 2 Rec. ITU-R P.2109-0 A statistical model that attempted to describe the entry loss characteri
15、stics of the global set of buildings would give a statistical distribution so broad as to be unhelpful. On the other hand, a model that attempted to characterise many different types of building would require more data than currently exists and would be inappropriate for generic sharing studies. The
16、 model is based on the measurement data collated in Report ITU-R P.2346 in the range 80 MHz to 73 GHz. 2 Parameters The model takes the following input parameters: frequency (0.08-100 GHz); the probability with which the loss is not exceeded; building class (traditional or thermally-efficient); elev
17、ation angle of the path at the building faade (degrees above the horizontal). The azimuth of the path to the outdoor terminal with respect to the building surface is not accounted for explicitly. Although theory and measurement show that signals normally incident on a building surface will suffer lo
18、wer loss than those arriving at oblique angles, the statistical output of the model represents the generality of building orientations with respect to the outdoor terminal. The model assumes that the indoor antenna is omnidirectional; the building entry loss will therefore take account of all energy
19、 arriving at the terminal location. Following the definition given in Recommendation ITU-R P.2040, building entry loss is here defined in isolation from any surrounding clutter. Should the building be surrounded by local clutter, additional losses may need to be determined for the relevant terminal
20、height and position above ground using Recommendation ITU-R P.2103-0. The model makes the implicit assumption that terminals have an equal probability of location at any point within a building. 2.1 Classification of building type Experimental results, such as those collated in Report ITU-R P.2346,
21、shows that, when characterised in terms of entry loss, buildings fall into two distinct populations: where modern, thermally-efficient building methods are used (metallised glass, foil-backed panels) building entry loss is generally significantly higher than for traditional buildings without such ma
22、terials. The model therefore gives predictions for these two cases. This classification, of thermally-efficient and traditional, refers purely to the thermal efficiency of construction materials. No assumption should be made on the year of construction, type (single or multi-floors), heritage or bui
23、lding method. For building entry loss, it is important to consider the thermal efficiency of the complete building (or the overall thermal efficiency). A highly thermally-efficient main structure with poorly insulated windows (e.g. single glazed with thin glass) can make the building thermally-ineff
24、icient and vice versa. Thermal transmittance, commonly referred as U-value, provides a quantifiable description of thermal efficiency. Low U-values represent high thermal efficiency. Typically, the presence of metallised Rec. ITU-R P.2109-0 3 glass windows, insulated cavity walls, thick reinforced c
25、oncrete and metal foil back cladding is a good indication1 of a thermally-efficient building. 3 Model Building entry loss will vary depending on building type, location within the building and movement in the building. The building entry loss distribution is given by a combination of two lognormal d
26、istributions. The building entry loss not exceeded for the probability, P, is given by: () = 10log(100.1() + 100.1() + 100.1 ) dB (1) where: () = 1()1 + 1 (2) () = 1()2 +2 (3) = 3.0 (4) 1 = + (5) 2 = + log() (6) 1 = + log() (7) 2 = + log() (8) where: Lh is the median loss for horizontal paths, given
27、 by: = + log()+ (log()2 (9) Le is the correction for elevation angle of the path at the building faade: = 0.212 | (10) and: f = frequency (GHz) = elevation angle of the path at the building faade (degrees) P = probability that loss is not exceeded (0.0 P 1.0) F-1(P) = inverse cumulative normal distr
28、ibution as a function of probability. and the coefficients are as given in Table 1: 1 For example, U-values of 0.3 and 0.9 are representative of thermally efficient main structure and metallised glass, respectively. 4 Rec. ITU-R P.2109-0 TABLE 1 Model coefficients Building type r s t u v w x y z Rel
29、ated to: Median BEL (1) 1 2 2 Traditional 12.64 3.72 0.96 9.6 2.0 9.1 3.0 4.5 2.0 Thermally-efficient 28.19 3.00 8.48 13.5 3.8 27.8 2.9 9.4 2.1 For illustration, Fig. 1 plots the median BEL (i.e. 1) returned by the model for the two building classes. In any sharing studies, the entire distribution should always be considered. FIGURE 1 Median building entry loss predicted at horizontal incidence P . 2 1 0 9 01-01020304050600 . 1 1 10 100Freq u en cy ( z)GHT rad i t i o n alT h erma l l y -effi ci en tMedian(dB)BEL
