Recommendation ITU-R P (06/2017)

Transcription

1 Recommenation ITU-R P (06/017) Propagation ata an preiction methos for the planning of short-range outoor raiocommunication systems an raio local area networks in the frequency range 300 MHz to 100 GHz P Series Raiowave propagation

2 ii Rec. ITU-R P Forewor The role of the Raiocommunication Sector is to ensure the rational, equitable, efficient an economical use of the raiofrequency spectrum by all raiocommunication services, incluing satellite services, an carry out stuies without limit of frequency range on the basis of which Recommenations are aopte. The regulatory an policy functions of the Raiocommunication Sector are performe by Worl an Regional Raiocommunication Conferences an Raiocommunication Assemblies supporte by Stuy Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is escribe in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC reference in Annex 1 of Resolution ITU-R 1. Forms to be use for the submission of patent statements an licensing eclarations by patent holers are available from where the Guielines for Implementation of the Common Patent Policy for ITU-T/ITU-R/ISO/IEC an the ITU-R patent information atabase can also be foun. Series of ITU-R Recommenations (Also available online at Series BO BR BS BT F M P RA RS S SA SF SM SNG TF V Title Satellite elivery Recoring for prouction, archival an play-out; film for television Broacasting service (soun) Broacasting service (television) Fixe service Mobile, raioetermination, amateur an relate satellite services Raiowave propagation Raio astronomy Remote sensing systems Fixe-satellite service Space applications an meteorology Frequency sharing an coorination between fixe-satellite an fixe service systems Spectrum management Satellite news gathering Time signals an frequency stanars emissions Vocabulary an relate subjects Note: This ITU-R Recommenation was approve in English uner the proceure etaile in Resolution ITU-R 1. Electronic Publication Geneva, 017 ITU 017 All rights reserve. No part of this publication may be reprouce, by any means whatsoever, without written permission of ITU.

3 Rec. ITU-R P Scope RECOMMENDATION ITU-R P Propagation ata an preiction methos for the planning of short-range outoor raiocommunication systems an raio local area networks in the frequency range 300 MHz to 100 GHz (Question ITU-R 11/3) ( ) This Recommenation provies guiance on outoor short-range propagation over the frequency range 300 MHz to 100 GHz. Information is given on path loss moels for line-of-sight (os) an non-line-of-sight (NoS) environments, builing entry loss, multipath moels for both environments of street canyon an over roof-tops, number of signal components, polarization characteristics an faing characteristics. This Recommenation can also be use in compatibility stuies. The ITU Raiocommunication Assembly, consiering a) that many new short-range (operating range less than 1 km) mobile an personal communication applications are being evelope; b) that there is a high eman for raio local area networks (RANs) an wireless local loop systems; c) that short-range systems using very low power have many avantages for proviing services in the mobile an wireless local loop environment; ) that knowlege of the propagation characteristics an the interference arising from multiple users in the same area is critical to the efficient esign of systems; e) that there is a nee both for general (i.e. site-inepenent) moels an avice for initial system planning an interference assessment, an for eterministic (or site-specific) moels for some etaile evaluations, noting a) that Recommenation ITU-R P.138 provies guiance on inoor propagation over the frequency range 300 MHz to 100 GHz, an shoul be consulte for those situations where both inoor an outoor conitions exist; b) that Recommenation ITU-R P.1546 provies guiance on propagation for systems that operate over istances of 1 km an greater, an over the frequency range 30 MHz to 3 GHz; c) that Recommenation ITU-R P.040 provies guiance on the effects of builing material properties an structures on raiowave propagation; ) that Recommenation ITU-R P.109 provies statistical moels for builing entry loss, recommens that the information an methos in Annex 1 shoul be aopte for the assessment of the propagation characteristics of short-range outoor raio systems between 300 MHz an 100 GHz where applicable.

4 Rec. ITU-R P Annex 1 1 Introuction Propagation over paths of length less than 1 km is affecte primarily by builings an trees, rather than by variations in groun elevation. The effect of builings is preominant, since most short-path raio links are foun in urban an suburban areas. The mobile terminal is most likely to be hel by a peestrian or locate in a vehicle. This Recommenation efines categories for short propagation paths, an provies methos for estimating path loss, elay sprea, angular sprea, an cross correlation over these paths. The propagation moels of these methos are symmetric in the sense that they treat raio terminals at both ens of a path in the same manner. From the moel s perspective, it oes not matter which terminal is the transmitter an which is the receiver. Hence the terms Station 1 an Station are use to enote the terminals at the start an en of the propagation path, respectively. Physical operating environments an efinition of cell types Environments escribe in this Recommenation are categorize solely from the raio propagation perspective. Raiowave propagation is influence by the environment, i.e. builing structures an heights, the usage of the mobile terminal (peestrian/vehicular) an the positions of the antennas. Five ifferent environments are ientifie, consiere to be the most typical. Hilly areas, for example, are not consiere, as they are less typical in metropolitan areas. Table 1 lists the five environments. Recognizing that there is a wie variety of environments within each category, it is not intene to moel every possible case but to give propagation moels that are representative of environments frequently encountere. TABE 1 Physical operating environments Propagation impairments Environment Urban very highrise Urban high-rise Description an propagation impairments of concern Busiest urban eep canyon, characterize by streets line with high-ensity builings with several tens of floors which results in an urban eep canyon High ense builings an skyscrapers interleave with each other which yiels to the rich scattering propagation paths in NoS Rows of tall builings provie the possibility of very long path elays Heavy traffic vehicles an high flowrate visitors in the area act as reflectors aing Doppler shift to the reflecte waves Trees besie the streets provie ynamic shaowing Urban canyon, characterize by streets line with tall builings of several floors each Builing height makes significant contributions from propagation over roof-tops unlikely Rows of tall builings provie the possibility of long path elays arge numbers of moving vehicles in the area act as reflectors aing Doppler shift to the reflecte waves

5 Rec. ITU-R P TABE 1 (en) Environment Urban lowrise/suburban Resiential Rural Description an propagation impairments of concern Typifie by wie streets Builing heights are generally less than three stories making iffraction over roof-top likely Reflections an shaowing from moving vehicles can sometimes occur Primary effects are long elays an small Doppler shifts Single an ouble storey wellings Roas are generally two lanes wie with cars parke along sies Heavy to light foliage possible Motor traffic usually light Small houses surroune by large garens Influence of terrain height (topography) Heavy to light foliage possible Motor traffic sometimes high For each of the five ifferent environments two possible scenarios for the mobile are consiere. Therefore the users are subivie into peestrian an vehicular users. For these two applications the velocity of the mobile is quite ifferent yieling ifferent Doppler shifts. Table shows typical velocities for these scenarios. Environment Urban very high-rise/urban highrise TABE Physical operating environments Typical mobile velocity Velocity for peestrian users (m/s) Velocity for vehicular users 1.5 Typical owntown spees aroun 50 km/h (14 m/s) Urban low-rise/suburban 1.5 Aroun 50 km/h (14 m/s) Expressways up to 100 km/h (8 m/s) Resiential 1.5 Aroun 40 km/h (11 m/s) Rural km/h (-8 m/s) The type of propagation mechanism that ominates epens also on the height of the base station antenna relative to the surrouning builings. Table 3 lists the typical cell types relevant for outoor short-path propagation.

6 4 Rec. ITU-R P Cell type Cell raius TABE 3 Definition of cell types Typical position of base station antenna Micro-cell 0.05 to 1 km Outoor; mounte above average roof-top level, heights of some surrouning builings may be above base station antenna height Dense urban microcell 0.05 to 0.5 km Outoor; mounte below average roof-top level Pico-cell Up to 50 m Inoor or outoor (mounte below roof-top level) (Note that ense urban micro-cell is not explicitly efine in Raiocommunication Stuy Group 5 Recommenation.) 3 Path categories 3.1 Definition of propagation situations Three levels of the location of the station can be consiere in this Recommenation. They are 1) over the roof-top (esignate as 1 in Fig. 1); ) below roof-top but above hea level (); an 3) at or below hea level (3). Comprehensively, six ifferent kins of links can be consiere epening on the locations of the stations, each of which may be os or NoS. Typical propagation situations in urban or suburban areas are epicte in Fig. 1. When one station (A) is mounte above roof-top level an another station (B or C) is locate at hea level, the corresponing cell is a micro-cell. The path can be os (A to C) or NoS (A to B). The propagation between the stations A an B is mainly over the roof-tops. When one station (D) is mounte below roof-top level but above hea level an another station (E or F) is locate at hea level in an urban or suburban environment, the corresponing cell is a micro- or pico-cellular environment. In these cell types, propagation is mainly within street canyons. For mobile-to-mobile links, both ens of the link can be assume to be at hea level. The path can be os (B to E) or NoS (E to F) Propagation over rooftops, non-line-of-sight (NoS) The typical NoS case (link A-B in Fig. 1) is escribe in Fig.. In the following, this case is calle NoS1.

7 Rec. ITU-R P FIGURE 1 Typical propagation situation in urban areas B(3) A(1) D() E(3) C(3) F(3) P FIGURE Definition of parameters for the NoS1 case Distance between STN1 an STNantennas: STN1 j STN Plan STN1 h 1 D h 1 q Cross-section Builing h r Dh h l w STN Dominant wave Direct wave One-time reflecte wave Two-time reflecte wave Several-time reflecte wave Diffracte wave b Three regions Direct wave ominant region Reflecte wave ominant region Diffracte wave ominant region Primary ominant wave Seconary ominant wave Non-ominant wave P The relevant parameters for this situation are: h r : average height of builings

8 6 Rec. ITU-R P w : b : j : h1 : h : l : street with average builing separation street orientation with respect to the irect path (egrees) Station 1 antenna height Station antenna height length of the path covere by builings : istance from Station 1 to Station. The NoS1 case frequently occurs in resiential/rural environments for all cell-types an is preominant for micro-cells in urban low-rise/suburban environments. The parameters hr, b an l can be erive from builing ata along the line between the antennas. However, the etermination of w an j requires a two-imensional analysis of the area aroun the mobile. Note that l is not necessarily normal to the builing orientation Propagation along street canyons, NoS Figure 3 epicts the situation for a typical ense urban micro-cellular NoS-case (link D-E in Fig. 1). In the following, this case is calle NoS. FIGURE 3 Definition of parameters for the NoS case x w x 1 w 1 a STN STN1 P The relevant parameters for this situation are: w1: street with at the position of the Station 1 w: street with at the position of the Station x1 : x : istance Station 1 to street crossing istance Station to street crossing a: is the corner angle (ra). NoS is the preominant path type in urban high-rise environments for all cell-types an occurs frequently in ense urban micro- an pico-cells in urban low-rise environments. The etermination of all parameters for the NoS case requires a two-imensional analysis of the area aroun the mobile.

9 Rec. ITU-R P ine-of-sight (os) paths The paths A-C, D-F, an B-E in Fig. 1 are examples of os situations. The same moels can be applie for these types of os path. 3. Data requirements For site-specific calculations in urban areas, ifferent types of ata can be use. The most accurate information can be erive from high-resolution ata where information consists of: builing structures; relative an absolute builing heights; vegetation information. Data formats can be both raster an vector. The location accuracy of the vector ata shoul be of the orer of 1 to m. The recommene resolution for the raster ata is 1 to 10 m. The height accuracy for both ata formats shoul be of the orer of 1 to m. If no high-resolution ata are available, low-resolution lan-use ata (50 m resolution) are recommene. Depening on the efinition of lan-use classes (ense urban, urban, suburban, etc.) the require parameters can be assigne to these lan-use classes. These ata can be use in conjunction with street vector information in orer to extract street orientation angles. 4 Path loss moels For typical scenarios in urban areas, some close-form algorithms can be applie. These propagation moels can be use both for site-specific an site-general calculations. The corresponing propagation situations are efine in 3.1. The type of the moel to be applie may epen also on the frequency range e.g. UHF, SHF an EHF (millimetre-wave). For site-specific calculations, ifferent moels have to be applie for UHF propagation an for millimetre-wave propagation. In the UHF frequency range, os an NoS situations are consiere. In mm-wave propagation, os is consiere only. Aitional attenuation by oxygen an hyrometeors shoul be consiere in the millimetre-wave frequency range. 4.1 Moels for propagation within street canyons Site-general moel This site-general moel is applicable to situations where both the transmitting an receiving stations are locate below-rooftop, regarless of their antenna heights. The site-general moel is provie by the following equation: where: : f : α : β : γ : N(0, σ): P(, f) = 10α log 10 () + β + 10γ log 10 (f) + N(0, σ) B (1) 3D irect istance between the transmitting an receiving stations operating frequency (GHz) coefficient associate with the increase of the path loss with istance coefficient associate with the offset value of the path loss coefficient associate with the increase of the path loss with frequency a zero mean Gaussian ranom variable with a stanar eviation σ (B).

10 8 Rec. ITU-R P The recommene values for os (e.g. D-F in Fig. 1) an NoS (e.g. D-E in Fig. 1) situations to be use for below-rooftop propagation in urban an suburban environments are provie in Table 4. TABE 4 Path loss coefficients for below-rooftop propagation Frequency range (GHz) Distance range Type of environment Urban highrise, Urban low-rise / Suburban os / NoS α β γ σ os Urban high-rise NoS Urban low-rise / Suburban NoS Site-specific moel for os situation This situation is epicte as the paths between A an C, D an F, or B an E in Fig. 1. UHF propagation In the UHF frequency range, basic transmission loss, as efine by Recommenation ITU-R P.341, can be characterize by two slopes an a single breakpoint. An approximate lower boun os,l is given by: os,l bp 0 log 40 log R bp R bp for for R R bp bp () where Rbp is the breakpoint istance in m an is given by: 4h 1h R bp (3) where is the wavelength. The lower boun is base on the two-ray plane earth reflection moel.

11 Rec. ITU-R P An approximate upper boun os,u is given by: os,u bp 5 log 0 40 log R bp R bp for for R R bp bp (4) bp is a value for the basic transmission loss at the break point, efine as: bp 0log 10 (5) 8 h1h The upper boun has the faing margin of 0 B. In equation (4), the attenuation coefficient before the breakpoint is set to.5 because a short istance leas to a weak shaowing effect. Accoring to the free-space loss curve, a meian value os,m is given by: os,m bp 0 log 6 40 log R bp R bp for for R R bp bp (6) SHF propagation up to 15 GHz At SHF, for path lengths up to about 1 km, roa traffic will influence the effective roa height an will thus affect the breakpoint istance. This istance, Rbp, is estimate by: ( h )( ) 4 1 hs h h R s bp (7) where hs is the effective roa height ue to such objects as vehicles on the roa an peestrians near the roaway. Hence hs epens on the traffic on the roa. The hs values given in Tables 5 an 6 are erive from aytime an night-time measurements, corresponing to heavy an light traffic conitions, respectively. Heavy traffic correspons to 10-0% of the roaway covere with vehicles, an 0.-1% of the footpath occupie by peestrians. ight traffic is % of the roaway an less than 0.001% of the footpath occupie. The roaway is 7 m wie, incluing 6 m wie footpaths on either sie.

12 10 Rec. ITU-R P Frequency (GHz) TABE 5 The effective height of the roa, hs (heavy traffic) h 1 (1) The breakpoint is beyon 1 km. () No breakpoint exists. h s h =.7 h = () () () () () 8 (1) () Frequency (GHz) TABE 6 The effective height of the roa, hs (light traffic) h 1 (1) No measurements taken. () The breakpoint is beyon 1 km. h s h =.7 h = (1) (1) 4 () () (1) 4 () () (1) When h1, h > hs, the approximate values of the upper an lower bouns of basic transmission loss for the SHF frequency ban can be calculate using equations () an (4), with bp given by: bp 0log10 8( h1 hs )( h hs ) (8) On the other han, when h1 hs or h hs no breakpoint exists. When two terminals are close ( < Rs), the basic propagation loss is similar to that of the UHF range. When two terminals are far, the propagation characteristic is such that the attenuation coefficient is cube. Therefore, the approximate lower boun for Rs is given by:

13 Rec. ITU-R P , l s 30 log (9) Rs os 10 The approximate upper boun for Rs is given by: The basic propagation loss s is efine as:, u s 0 30log (10) Rs os 10 s 0log10 (11) Rs Rs in equations (9) to (11) has been experimentally etermine to be 0 m. Base on measurements, a meian value is given by: Millimetre-wave propagation, m s 6 30log (1) Rs os 10 At frequencies above about 10 GHz, the breakpoint istance Rbp in equation (3) is far beyon the expecte maximum cell raius (500 m). This means that no fourth-power law is expecte in this frequency ban. Hence the power istance ecay-rate will nearly follow the free-space law with a path-loss exponent of about With irectional antennas, the path loss when the boresights of the antennas are aligne is given by os 10 n gas rain B (13) 0 log 10 where n is the path loss exponent, is the istance between Station 1 an Station an 0 is the path loss at the reference istance 0. For a reference istance 0 at 1 m, an assuming free-space propagation 0=0 log 10 f 8 where f is in MHz. gas an rain, are attenuation by atmospheric gases an by rain which can be calculate from Recommenation ITU-R P.676 an Recommenation ITU-R P.530, respectively. Values of path loss exponent n are liste in Table 7. Frequency (GHz) 8 0 TABE 7 Directional path loss coefficients for millimetre-wave propagation Type of environment Half power beam with (egree) Path loss exponent Tx Ant Rx Ant n Urban very high-rise Urban low-rise Urban low rise

14 1 Rec. ITU-R P Site-specific moel for NoS situations This situation is epicte as the paths between D an E in Fig Frequency range from 800 to 000 MHz For NoS situations where both antennas are below roof-top level, iffracte an reflecte waves at the corners of the street crossings have to be consiere (see Fig. 3). where: r : /10 /10 10log10 10 r 10 NoS B (14) reflection path loss efine by: where: f ( a) 4 r 0 log10 ( x1 x) x1x 0 log10 B (15) w w 1 where 0.6 < a [ra] <. : iffraction path loss efine by: 3.86 f ( a) B (16) 3.5 a log10x1x ( x1 x) Da a 0 log10 B (17) 40 x arctan x D arctan 1 a B (18) w w Frequency range from to 38 GHz The propagation moel for the NoS situations as escribe in 3.1. with the corner angle a = / ra is erive base on measurements at a frequency range from to 38 GHz, where h1, h < hr an w is up to 10 m (or siewalk). The path loss characteristics can be ivie into two parts: the corner loss region an the NoS region. The corner loss region extens for corner from the point which is 1 m own the ege of the os street into the NoS street. The corner loss (corner) is expresse as the aitional attenuation over the istance corner. The NoS region lies beyon the corner loss region, where a coefficient parameter () applies. This is illustrate by the typical curve shown in Fig. 4. Using x1, x, an w1, as shown in Fig. 3, the overall path loss (NoS) beyon the corner region (x > w1/ + 1) is foun using: NoS os c att (19) c corner log10x w1 w1 1 x w1 1 corner log 1 corner (0) 10 corner x w1 1 corner

15 Rec. ITU-R P att 10 log 0 10 x 1 x1 x w / 1 corner x x w w 1 1 / 1 / 1 corner corner (1) where os is the path loss in the os street for x1 (> 0 m), as calculate in In equation (0), corner is given as 0 B in an urban environment an 30 B in a resiential environment. An corner is 30 m in both environments. In equation (1), β = 6 in urban an resiential environments for wege-shape builings at four corners of the intersection as illustrate in case (1) of Fig. 5. If a particular builing is chamfere at the intersection in urban environments as illustrate in case () of Fig. 5, β is calculate by equation (). Because the specular reflection paths from chamfere-shape builings significantly affect path loss in NoS region, the path loss for case () is ifferent from that for case (1). where f is frequency in MHz. 1.4log f log x () FIGURE 4 Typical tren of propagation along street canyons with low station height for frequency range from to 38 GHz Relative signal level os region Corner region NoS region os Relative signal level NoS corner att w corner STN1 x 1 x Distance of travel from station 1 STN P

16 14 Rec. ITU-R P FIGURE 5 Case (1) Wege shape builings layout Case () Chamfere shape builings layout x x w STN w STN x 1 w 1 x 1 w 1 STN1 STN1 P In a resiential environment, the path loss oes not increase monotonically with istance, an thus the coefficient parameter may be lower than the value in an urban environment, owing to the presence of alleys an gaps between the houses. With a high base station antenna in the small macro-cell, the effects of iffraction over roof-tops are more significant. Consequently, the propagation characteristics o not epen on the corner loss. 4. Moels for propagation over roof-tops 4..1 Site-general moel This site-general moel is applicable to situations where one of the stations is locate above-rooftop an the other station is locate below-rooftop, regarless of their antenna heights. The site-general moel is the same as equation (1) escribe for the site-general moel for propagation below-rooftop (within street canyons). The recommene values for os (e.g. A-C in Fig. 1) an NoS (e.g. A-B in Fig. 1) situations to be use for above-rooftop propagation in urban an suburban environments are provie in Table 8. Frequency range (GHz) TABE 8 Path loss coefficients for above-rooftop propagation Distance range Type of environment Urban highrise, Urban low-rise / Suburban os / NoS α β γ σ os Urban high-rise NoS Site-specific moel NoS signals can arrive at the station by iffraction mechanisms or by multipath which may be a combination of iffraction an reflection mechanisms. This section evelops moels that relate to iffraction mechanisms.

17 Rec. ITU-R P Propagation for urban area Moels are efine for the paths A (h1) to B (h) an D (h1) to B (h) as epicte in Fig. 1. The moels are vali for: h1: 4 to 50 m h: 1 to 3 m f: 800 to MHz to 16 GHz for h1 < hr an w < 10 m (or siewalk) : 0 to m. (Note that although the moel is vali up to 5 km, this Recommenation is intene for istances only up to 1 km.) Propagation for suburban area Moel is efine for the path A (h1) to B (h) as epicte in Fig. 1. The moel is vali for: hr: Dh1: Dh: any height m 1 to 100 m 4 to 10 (less than hr) m h1: hr + Dh1 m h: hr Dh m f: 0.8 to 38 GHz w: 10 to 5 m : 10 to m (Note that although the moel is vali up to 5 km, this Recommenation is intene for istances only up to 1 km.) Millimetre-wave propagation Millimetre-wave signal coverage is consiere only for os an NoS reflection situations because of the large iffraction losses experience when obstacles cause the propagation path to become NoS. For NoS situations, multipath reflections an scattering will be the most likely signal propagation metho. The frequency range (f) for the suburban area propagation moel ( 4...) is applicable up to 38 GHz Urban area The multi-screen iffraction moel given below is vali if the roof-tops are all about the same height. Assuming the roof-top heights iffer only by an amount less than the first Fresnel-zone raius over a path of length l (see Fig. ), the roof-top height to use in the moel is the average roof-top height. If the roof-top heights vary by much more than the first Fresnel-zone raius, a preferre metho is to use the highest builings along the path in a knife-ege iffraction calculation, as escribe in Recommenation ITU-R P.56, to replace the multi-screen moel. In the moel for transmission loss in the NoS1-case (see Fig. ) for roof-tops of similar height, the loss between isotropic antennas is expresse as the sum of free-space loss, bf, the iffraction loss from roof-top to street rts an the reuction ue to multiple screen iffraction past rows of builings, ms. In this moel bf an rts are inepenent of the station antenna height, while ms is epenent on whether the station antenna is at, below or above builing heights.

18 16 Rec. ITU-R P The free-space loss is given by: where: : f : bf rts ms for rts ms 0 NoS1 (3) bf for rts ms 0 bf path length ; frequency (MHz). /1000 0log ( ) 3.4 0log10 10 f (4) The term rts escribes the coupling of the wave propagating along the multiple-screen path into the street where the mobile station is locate. It takes into account the with of the street an its orientation. where: rts 8. 10log ( w) 10log 10( f ) 0log 10( Dh ) ori 10 (5) j for 0 j 35 ori ( j 35) for 35 j 55 (6) ( j 55) for 55 j 90 D h (7) hr h ori is the street orientation correction factor, which takes into account the effect of roof-top-to-street iffraction into streets that are not perpenicular to the irection of propagation (see Fig. ). The multiple screen iffraction loss from Station 1 ue to propagation past rows of builings epens on the antenna height relative to the builing heights an on the incience angle. A criterion for grazing incience is the settle fiel istance, s: where (see Fig. ): s (8) Dh 1 Dh1 h1 h r (9) For the calculation of ms, s is compare to the istance l over which the builings exten. The calculation for ms uses the following proceure to remove any iscontinuity between the ifferent moels use when the length of builings is greater or less than the settle fiel istance. The overall multiple screen iffraction moel loss is given by:

19 Rec. ITU-R P ms where: log log tanh log tanh ms log 1 ms tanh log ms tanh log bp bp log log 1 ms ms bp bp mi upp mi mi mi mi low mi upp mi mi low for l for l for s s for l s for l an h an h s an h bp bp h an h bp bp bp (30) h bp upp low (31) ) ( upp low (3) an mi ( upp low) (33) 1 upp ms bp (34) low ms bp (35) 1 bp Dh 1 (36) = [0.0417] = [0.1] where the iniviual moel losses, 1ms () an ms (), are efine as follows: Calculation of 1ms for l > s (Note this calculation becomes more accurate when l >> s.) k k log ( / 1 000) k log ( f ) 9 log ( ) 1ms bsh a 10 f b (37)

20 18 Rec. ITU-R P where: bsh 18 log 10(1 Dh1 ) for h1 hr 0 for h1 hr (38) is a loss term that epens on the antenna height: k a 71.4 for h1 hr an f 000 MHz Dh1 for h1 hr, f 000 MHz an 500 m Dh1 /1 000 for h1 hr, f 000 MHz an 500 m 54 for h1 hr an f 000 MHz Dh1 for h1 hr, f 000 MHz an 500 m Dh 1 /1 000 for h1 hr, f 000 MHz an 500m (39) k 18 Dh hr 8 for f 000 MHz 4 0.7( f / 95 1) for meium size city an suburban k f (41) centres with meium tree ensity an f 000 MHz 4 1.5( f / 95 1) for metropolitan centres an f 000 MHz Calculation of ms for l < s In this case a further istinction has to be mae accoring to the relative heights of the antenna an the roof-tops: where: 1 for for h h 1 1 h r h Q r (40) ms 10 log 10 M (4) Q M 0.9 Dh b.35 1 b b 1 1 q q for for for h1 hr h1 hr h h 1 r h u h u h l an h 1 h r h l (43) an

21 Rec. ITU-R P Dh q arctan 1 (44) b 1 b Dh (45) an b log b log10 log h 10 (46) u 4... Suburban area b 0.187b h l b (47).938 log 10 f A propagation moel for the NoS1-Case base on geometrical optics (GO) is shown in Fig.. This Figure inicates that the composition of the arriving waves at Station changes accoring to the Station 1-Station istance. A irect wave can arrive at Station only when the Station 1-Station istance is very short. The several-time (one-, two-, or three-time) reflecte waves, which have a relatively strong level, can arrive at Station when the Station 1-Station separation is relatively short. When the Station 1-Station separation is long, the several-time reflecte waves cannot arrive an only many-time reflecte waves, which have weak level besie that of iffracte waves from builing roofs, arrive at Station. Base on these propagation mechanisms, the loss ue to the istance between isotropic antennas can be ivie into three regions in terms of the ominant arrival waves at Station. These are the irect wave, reflecte wave, an iffracte wave ominant regions. The loss in each region is expresse as follows base on GO. NoS1 4 0log10 0n 3.1log10 RD RD for for for 0 0 RD RD (Direct wave ominant region) (Reflecte wave ominant region) (Diffracte wave ominant region) (48) where: 0n k k k 1 k 1 RD RD k k k k k k when k 0,1,... when k k k 1 RD RD k 1 (49) k = ( B k sin φ ) + (h 1 h ) (50)

22 0 Rec. ITU-R P kp k 0log10 k (51) RD (f) = ( ) log 10 (f) (5) (0.8 GHz f 38 GHz) RD k k 1 k 1 k k RD k k RD k 1 (53) kp Ak ( h1 h ) sin (54) jk B k k 1 1 h h w h h k A 1 1 h h r r w h h k k w (55) (56) j k tan 1 A B k k tan j (57) 4.3 Moels for propagation between terminals locate from below roof-top height to near street level The moels escribe below are intene for calculating the basic transmission loss between two terminals of low height in urban or resiential environments. This situation is epicte as the paths between D an F, D an E, B an E, or E an F in Fig. 1. The site-general moel in urban environments is escribe in The site-specific moel within street canyon is escribe in 4.3. an the moel in resiential environments is in These moels are recommene for propagation between low-height terminals where both terminal antenna heights are near street level well below roof-top height, but are otherwise unspecifie. It is reciprocal with respect to transmitter an receiver Site-general moel The moel inclues both os an NoS regions, an moels the rapi ecrease in signal level note at the corner between the os an NoS regions. The moel inclues the statistics of location variability in the os an NoS regions, an provies a statistical moel for the corner istance between the os an NoS regions. Figure 6 illustrates the os, NoS an corner regions, an the statistical variability preicte by the moel. The moel is vali for frequencies in the MHz range. The moel is base on measurements mae with antenna heights between 1.9 an 3.0 m above groun, an transmitter-receiver istances up to m.

23 Rec. ITU-R P FIGURE 6 Curves of basic transmission loss not exceee for 1, 10, 50, 90 an 99% of locations (frequency = 400 MHz, suburban) 0 0 Basic transmission loss (B) % 10% 50% 90% 99% Distance P The parameters require are the frequency f (MHz) an the istance between the terminals. Step 1: Calculate the meian value of the line-of-sight loss: meian os ( ) log f 0 log ( /1 000) (58) Step : For the require location percentage, p (%), calculate the os location correction: D os ( p) ln(1 p /100) with = 7 B (59) Alternatively, values of the os correction for p = 1, 10, 50, 90 an 99% are given in Table 9. Step 3: A the os location correction to the meian value of os loss: os (, p) ( ) D ( p) Step 4: Calculate the meian value of the NoS loss: meian os os (60) meian NoS ( ) log10 f 40 log10( /1 000) urban (61) urban epens on the urban category an is 0 B for suburban, 6.8 B for urban an.3 B for ense urban/high-rise. Step 5: For the require location percentage, p (%), a the NoS location correction: 1 p D ( p) N ( /100) with = 7 B (6) NoS

24 Rec. ITU-R P N 1 (.) is the inverse normal cumulative istribution function. An approximation to this function, goo for p between 1 an 99% is given by the location variability function Qi(x) of Recommenation ITU-R P Alternatively, values of the NoS location correction for p = 1, 10, 50, 90 an 99% are given in Table 9. TABE 9 Table of os an NoS location variability corrections p (%) D os D NoS os (B) (B) Step 6: A the NoS location correction to the meian value of NoS loss: NoS meian NoS (, p) ( ) D ( p) (63) Step 7: For the require location percentage, p (%), calculate the istance os for which the os fraction FoS equals p: os NoS ( p) 1 log10( p /100) 64 log10( p /100) ( p) ( p /100) os if p 45 otherwise Values of os for p = 1, 10, 50, 90 an 99% are given in Table 9. This moel has not been teste for p < 0.1%. The statistics were obtaine from two cities in the Unite Kingom an may be ifferent in other countries. Alternatively, if the corner istance is known in a particular case, set os(p) to this istance. Step 8: The path loss at the istance is then given as: a) If < os, then (, p) = os(, p) b) If > os + w, then (, p) = NoS(, p) c) Otherwise linearly interpolate between the values os(os, p) an NoS(oS + w, p): os NoS os (, p) ( NoS os os (, p) os ( w, p) NoS os )( os ) / w The with w is introuce to provie a transition region between the os an NoS regions. This transition region is seen in the ata an typically has a with of w = 0 m Site-specific moel in urban environments This site-specific moel consists of os, 1-Turn NoS, an -Turn NoS situations in rectilinear street gri environments. This moel is base on measurement ata at frequencies: 430, 750, 905, 1 834, 400, an MHz with antenna heights between 1.5 an 4.0 m above groun. The maximum istance between terminals is up to m. (64)

25 Rec. ITU-R P os situation This situation is epicte as the path between B an E, or D an F in Fig. 1. The propagation loss is the same to that in NoS situations NoS conitions correspon to the E-F an D-E paths with an 3 antenna heights in urban environments. 1-Turn NoS propagation A 1-Turn NoS situation between Station 1 an Station is epicte in Fig. 7 ue to a corner along the route between Station 1 an Station. The istance between the corner an Station 1 is enote by x1 an the istance between the corner an Station is enote by x. FIGURE 7 1-Turn NoS ink between Station 1 an Station x STN x 1 STN1 P The path loss in this situation can be calculate by: 10log x x 0log (B), max( S 1 1Turn os corner x1 x where os is the path loss with istance = x1 + x, as calculate in 4.1.1, an S1 is a scattering/iffraction parameter calculate by: S 4 1 ( ) with an operating frequency f in Hz. This relationship between S1 an f is obtaine by a regression fitting with measurement ata at frequency ranging from 430 MHz to MHz. corner is an environmental variable etermine by street layouts (incluing street withs an os interval length x1) to account for a lower boun of vali istance range for equation (65). As an example 4.1.., 30 m can be use for urban areas. The path loss for the corner transition interval, i.e. 0 x max(s1,corner), can be etermine by interpolation between the path loss at the os ening position (i.e. x = 0) an that at x = max(s1,corner). S f 0.46 x, ) (65) (66)

26 4 Rec. ITU-R P Turn NoS propagation FIGURE 8 Two travel paths (soli line & ashe line) for a -turn NoS link STN1 STN P Unlike os an 1-Turn NoS links, it is possible to establish multiple travel route paths for a -Turn NoS link, e.g. shown in Fig. 8. Thus, the receive signal power gain (from Station 1 to Station ) is calculate consiering all -Turn route paths. Since receive power gain an path loss are logarithmically an inversely relate, the receive power gain can be written by: 10 1 /10 Turn Turn, n / 10 n 10 1 (67) where -Turn is the overall pass loss from Station 1 an Station, an -Turn,n enotes the path loss along with the nth -Turn route path. Therefore, Turn 10 log 10 n 10 1 Turn, n /10 B (68) To calculate the path loss along the nth route path, i.e. -Turn,n in equation (68), we consier a -Turn NoS situation is epicte in Fig. 9. This link path situation is characterize by three istance components: x1, x, an x3, where: x1 enotes the istance between Station 1 an the first corner, x enotes the istance between the first corner an the secon corner, x3 enotes the istance between the secon corner an Station.

27 Rec. ITU-R P FIGURE 9 -Turn NoS link between Station 1 an Station STN x 3 x x 1 STN1 P Then, the propagation path loss between Station 1 an Station is calculate by: x1, nx, nx3, n Turn, n os 10log 10 0log 10 S1 0log 10 S x3, n max( S, corner) (69) x x x 1, n, n 3, n where os is the path loss with istance =x1,n+x,n+x3,n, as calculate in S1 is a scattering/iffraction parameter for the first corner turn obtaine by (66), an S is a parameter for the secon corner turn effect calculate by: S 0. f (70) 54 ike S1, the relationship between S an f (in Hz) is obtaine by a regression fitting with measurement ata at frequency ranging from 430 MHz to MHz. corner can be similarly etermine as in 1-Turn NoS situations. The path loss in the corner transition interval, i.e. 0 x3,n max(s,corner), can be also etermine by interpolation between the path loss at the 1-Turn NoS ening position (i.e. x3,n=0) an that x3,n=max(s,corner) Site-specific moel in resiential environments Figure 10 escribes a propagation moel that preicts whole path loss between two terminals of low height in resiential environments as represente by equation (71) by using path loss along a roa r, path loss between houses b, an over-roof propagation path loss v. r, b, an v are respectively calculate by equations (7)-(74), (75), an (76)-(81). Applicable areas are both os an NoS regions that inclue areas having two or more corners. The path loss along a roa r is ominant at a relatively nearby transmitter where there are only a few corners an the path loss between houses b becomes ominant as the istance between terminals increases because r increases as the number of corners increases. The over-roof propagation path loss v becomes ominant relatively far from the transmitter where b increases by multiple shieling of the builings an houses. This moel is recommene for frequencies in the -6 GHz range. The maximum istance between terminals is up to m. The applicable roa angle range is 0-90 egrees. The applicable range of the terminal antenna height is set at from 1. m to hbmin, where hbmin is the height of the lowest builing in the area (normally 6 m for a etache house in a resiential area).

28 6 Rec. ITU-R P FIGURE 10 Propagation moel for paths between terminals locate below roof-top height y Rx b Tx r P ( r /10) ( b /10) ( v /10) 10log(1/10 1/10 1/10 ) (71) rbc ( before corner ) r (7) rac ( after corner ) rbc 0log(4 / ) (73) 5 rac rbc ( 7.18log( qi ) 0.97log( f ) 6.1) 1 exp qix1i xi (74) i b 0log(4 / ) 30.6 log( / R) 6.88log( f ) 5.76 (75) v log(4 / ) 1 c 0 (76).9 0 log ( v 0.1) 1 v 0.1 (77) log ( v 0.1) 1 v 0.1 (78) 6 v1 hbtx htx 1 1 a b (79) v hbrx hrx 1 1 b c (80) ( a b)( b c) c 10 log b( a b c) (81)

29 Rec. ITU-R P The relevant parameters for this moel are: : istance between two terminals : wavelength f: frequency (GHz) qi: roa angle of i-th corner (egrees) x1i: roa istance from transmitter to i-th corner xi: roa istance from i-th corner to receiver R: mean visible istance hbtx: height of nearest builing from transmitter in receiver irection hbrx: height of nearest builing from receiver in transmitter irection htx: transmitter antenna height hrx: receiver antenna height a: istance between transmitter an nearest builing from transmitter b: istance between nearest builings from transmitter an receiver c: istance between receiver an nearest builing from receiver. Figures 11 an 1 below respectively escribe the geometries an the parameters. The mean visible istance R is calculate by equations (8)-(85). In the equations, n is the builing ensity (builings/km ), m is the average builing height of the builings with less than 3 stories, l is the lowest builing s height, which is normally 6, an l3 is the height of a 3 story builing, which is normally 1. R nw 1000 p (1 e hrx l exp ) m l (8) w 4 a(1 e ) w0 1 exp (83) (1 e ) p h Rx l3 h Rx, 1 ( m l ) m l (84) w 15 [ m], a 0.55, 0.18[ m ] (85) 0 1

30 8 Rec. ITU-R P FIGURE 11 Roa geometry an parameters (example for two corners) x 11 q 1 Tx Before corner x 1 Tx x 1 1st corner n corner Rx n corner x Rx q P FIGURE 1 Sie view of builing geometry an parameters h btx h brx h Tx h Rx Tx a b Tx b b Rx c Rx P Default parameters for site-general calculations If the ata on the structure of builings an roas are unknown (site-general situations), the following efault values are recommene: hr = roof-height = 3 (number of floors) + roof-height 3 m for pitche roofs = 0 m for flat roofs w = b/ b = j = to 50 m 4.5 Aitional losses Influence of vegetation The effects of propagation through vegetation (primarily trees) are important for outoor short-path preictions. Two major propagation mechanisms can be ientifie: propagation through (not aroun or over) trees; propagation over trees. The first mechanism preominates for geometries in which both antennas are below the tree tops an the istance through the trees is small, while the latter preominates for geometries in which one antenna is elevate above the tree tops. The attenuation is strongly affecte by multipath scattering initiate by iffraction of the signal energy both over an through the tree structures. For propagation through trees, the specific attenuation in vegetation can be foun in Recommenation ITU-R P.833.

31 Rec. ITU-R P In situations where the propagation is over trees, iffraction is the major propagation moe over the eges of the trees closest to the low antenna. This propagation moe can be moelle most simply by using an ieal knife-ege iffraction moel (see Recommenation ITU-R P.56), although the knifeege moel may unerestimate the fiel strength, because it neglects multiple scattering by tree-tops, a mechanism that may be moelle by raiative transfer theory Builing entry loss Builing entry loss shoul be consiere when evaluating the raio coverage from an outoor system to an inoor terminal. It is also important for consiering interference problems between outoor systems an inoor systems. Definitions, theoretical moels an empirical results relating to builing entry loss can be foun in Recommenations ITU-R P.109 an ITU-R P Multipath moels A escription of multipath propagation an efinition of terms are provie in Recommenation ITU-R P Delay profile Delay sprea for over roof-tops propagation environments Characteristics of multipath elay sprea for both os an NoS case in an urban high-rise environment for micro-cells (as efine in Table 3) have been evelope base on measure ata at MHz, MHz an MHz using omniirectional antennas. The meian r.m.s. elay sprea S in this environment is given by: S u exp A B ns (86) where both A an B are coefficients of r.m.s. elay sprea an is path loss (B). Table 10 lists the typical values of the coefficients for istances of 100 m 1 km base on measurements mae in urban areas. TABE 10 Typical coefficients for r.m.s. elay sprea Measurement conitions Coefficients of r.m.s. elay sprea Area Urban Frequency (GHz) Range MHz MHz, MHz A B The istributions of the multipath elay characteristics for the 3.7 GHz ban in an urban environment with Station 1 antenna height of 40 m an 60 m, an Station antenna height of m were erive from measurements. The istributions of the multipath elay characteristics for the 3.7 GHz an 5. GHz ban in a suburban environment with Station 1 antenna height of 0 m, an Station antenna height of.0 m an.8 m were erive from measurements. Table 11 lists the measure r.m.s. elay

32 30 Rec. ITU-R P sprea for frequencies from 1.9 to 73 GHz for cases where the cumulative probability is 50% an 95%. For r.m.s. elay sprea calculation, threshol level of 0 B was use, unless otherwise note. TABE 11 Typical r.m.s. elay sprea values Measurement conitions r.m.s. elay sprea (ns) Area Scenar io f (GHz) h 1 h Range TX beamwith (egree) RX beamwith (egree) Time elay resolution (ns) Polariza tion 50% 95% os UA (4) UCA (5) 10 VV 08 (1) 461 (1) NoS UA (4) UCA (5) 10 Dual (6) 407 (1) 513 (1) omni omni 10 VV 3 (1) 408 (1) omni omni 10 VV 11 (1) 357 (1) Urban very highrise omni 0.5 VV. () 6.9 () HV 9.8 () 8.1 () VV/HH 1.6 () 40. () Urban highrise os VH/HV.7 () 37.9 () VV/HH 7.5 (3) 9.1 (3) VH/HV 4.8 (3) 81.9 (3) VV/HH 1.7 () 31.3 () VH/HV () 19. () VV/HH 6 (3) 78.7 (3) omni 0.5 VV omni omni 16.6 VV 490 (1) 1490 (1) NoS omni 0.5 VV Suburb an os omni 100 VV omni 100 VV omni omni 10 VV 15 (1) 54 (1) omni omni 18.3 VV 189 (1) 577 (1) omni 100 VV (1) Threshol value of 30 B was use for r.m.s. elay sprea calculation. () Receiver antenna rotate aroun 360 egrees. The values represent when the bore-sight of receiver antenna is aligne to the irection of transmitter. (3) Receiver antenna rotate in a step of 5 o aroun 360 egrees. The value represents a irectional elay sprea when the bore-sight of receiver antenna is not aligne to the irection of transmitter. (4) Uniform inear-array Antenna. (5) Uniform Circular-array Antenna. (6) Mean value of VV, VH, HV, an HH.

33 Rec. ITU-R P Delay sprea for below roof-tops propagation environments Omniirectional antenna case Characteristics of multipath elay sprea for the os omniirectional antenna case in an urban highrise environment for ense urban micro-cells an pico-cells (as efine in Table 3) have been evelope base on measure ata at frequencies from.5 to GHz at istances from 50 to 400 m. The r.m.s. elay sprea S at istance of m follows a normal istribution with the mean value given by: an the stanar eviation given by: a s C a ns (87) a C s ns (88) where Ca, a, C an epen on the antenna height an propagation environment. Table 1 lists some typical values of the coefficients for istances of m base on measurements mae in urban an resiential areas. TABE 1 Typical coefficients for the istance characteristics of r.m.s. elay sprea for omniirectional antenna case Area Measurement conitions as s f (GHz) h 1 h Ca a C Urban (1) Urban () Resiential () (1) Threshol value of 0 B is use for r.m.s. elay sprea calculation. () Threshol value of 30 B is use for r.m.s. elay sprea calculation. From the measure ata at.5 GHz, the average shape of the elay profile was foun to be: ( t/ 0 P t) P 50 e 1 B (89)

34 3 Rec. ITU-R P where: an t is in ns. P0 : peak power (B) : ecay factor From the measure ata, for an r.m.s. elay sprea S, can be estimate as: A linear relationship between an S is only vali for the os case. 4 S 66 ns (90) From the same measurement set, the instantaneous properties of the elay profile have also been characterize. The energy arriving in the first 40 ns has a Rician istribution with a K-factor of about 6 to 9 B, while the energy arriving later has a Rayleigh or Rician istribution with a K-factor of up to about 3 B. (See Recommenation ITU-R P.1057 for efinitions of probability istributions.) Directional antenna case In fixe wireless access systems an communications between the access points of wireless mesh network systems, irectional antennas are employe as transmitter an receiver antennas. A typical effect of the use of irectional antennas is given hereafter. Arriving elaye waves are suppresse by the antenna pattern using irectional antennas as the transmitter an receiver antennas. Therefore, the elay sprea becomes small. In aition, the receive power increases with the antenna gain, when irectional antennas are employe as the transmitter an receiver antennas. Base on these facts, the irectional antenna is use in wireless systems. Therefore, it is important to unerstan the effect of antenna irectivity in multipath moels. Millimetre-wave raio systems are expecte to use irectional antennas with single polarisation or ual polarisation. Table 13 gives r.m.s. elay sprea values obtaine from 5 to 73 GHz with either ual polarise antennas or single polarise antennas at Station 1 an Station. For r.m.s. elay sprea calculation, threshol level of 0 B was use.