International Journal of Scientific & Engineering Research, Volume 5, Issue 4, April-2014 1109

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Outdoor Propagation Path Loss Models: A Review

Archana1, J.P.Sharma2, Dinesh.Sharma3 , Purnima K Sharma4

Abstract— This paper characterize different propagation path loss models as they are vary from one destination to another destination. The propagation path loss models is an important issues in desiging of a telecommunication system in wireless communication. Telecommunication sector is growing per day by day. The evolution of mobile service are growing with faster rate from 2nd generation GSM service to 3rd generation UMTS service to 4thgeneration LTE network. This paper begins with a review of the information available on the various propagation path loss models for outdoor models. The main characteristies of radio channels is path loss, fading and time delay spread. Effeciency of path loss models vary as the environment is change. The propagation model are useful for predicting the signal attenuation or path loss between the transmitter and receiver. This path loss information may be used as a controlling factor for wireless communication system performance to achieve the

perfect network planning.

Index Terms— Propagation model,Path loss,Free space,Received signal strength, W ireless communication,Okumara,Hata,cost-231

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Propagation models predict the mean signal strength for an arbitrary transmitter separation distance[6].In wireless com- munication signal is transmitted by transmitting antenna and received by receiving antenna any distortion in signal strength at receiver is known as path loss[7].
Path loss arise when the electromagnetic wave
propagates through space from transmitter to receiver. In gen-
PL=Power transmitted/Power received (db)

Fig.1 Basic Path loss Model


Archana (M.Tech., Student) , SCET,mahendergarh,India .


J.P.Sharma , Aassistant Pprofessor(ECE dept.) SCET,mahendergarh ,India

Dinesh Sharma, Assistant Pprofessor (ECE dept.) DAVCET,kanin, India.

Purnima k Sharma, AssistantPprofessor (ECE dept.)DAVCET,kanina, India.

There are many factors which is responsible for path loss. Some causes of path loss is:-

Free space





The propagation path loss model is an empirical math- ematical formulation to characterize behaviour of the radio Waves as a function of the radio waves as a function of fre- quency, surrounding environment and distance[9].

2. Propagation Path Loss Model

The propagation path loss model basically of two types:-

Empirical(Statistical) models

Physical(Determinstic) models

The Empirical models are based on practically measured data.
This models are simple but not very accurate. The empirical
model include Hata model, okumara model and cost 231 model. On the other way deterministic models are very accu- rate.for example Ray tracing and Ikegami model
A propagation model describes the average signal propaga- tion and it provides the maximum cell range with respect to the maximum propagation loss. It depends on the following:-

Environments(such as urban, sea, rural, forest, dense




Atmospheric conditions.


2.1 Okumara Model

Okumara’s model is empirical models for signal prediction in urban areas. This model is applicable for frequencies in the range 150 MHZ to 1920 MHZ(extended upto 3000MHZ) and distances of 1Km to 100 Km.[6]Okumara is the model to find path loss in urban area. The basis of the method is that the free space path loss between the transmitter and receiver is added

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to the value of Amu (f,d), where Amu is the median attenua- tion, relative to free space in the urban area with a base station effective antenna height G(htr) 200 meter and mobile station height G(htt) is 3 meter as shown in fig2. To determine path loss between the points of interest is first determined, and then the value of Amu(f,d) is added to it along with correction fac- tors to account for the type of terrain as expressed in:-
PLOK (50)(db)=La +Ama (f,d) -G(htr )-G(htt) -Garea
G(htt )=10log10 (htt /200) htt <3m
G(htt )=20log10 (htt /200) 10m>htt <3m

G(htr )=20log10 (htr /3)
Fig.3 Correction factor Garea for different types of ter- rain{from[oku68]@IEEE}

2.2 Hata Model

The hata model is the empirical mathematical relationship to describe the graphical path loss data provided by okumara’s model. The formula for the median path loss is:-
PLHA(urban)(db)=69.55+26.16log10 fc-13.82log10 htr - a(htt )+(44.9-6.55log10 htr ).log10 D
PLHA(suburban)(db)=69.55+26.16log10 fc-13.82log10 htr - a(htt )+(44.9-6.55log10 tr).log10 D-5.4+2[log10 (fc/28)]2
PLHA(open)(db)=69.55+26.16log10 fc-13.82log10 htr -a(htt )+(44.9-
6.55log10 htr ).log10 D-40.99+4.78[log10 (fc)2]-18.33log10 (fc)
Fig.2 Median attenuation relative to free space(Amu(f,d)),over a quasi-smoth terrain{from[oku68]@IEEE}
PL OK (db) is the percentile value of propagation path loss, La is propagation loss of free space,Ama is the median attenuation relative to free space, G(htr ), G(htt ), Garea are BTS antenna height gain factor, mobile antenna height gain factor, mobile antenna height gain factor and gain due to the type of envi- ronment. Correction factors can be added using a graphical form to allow for transmission in suburban and open areas and irregular terrain. The parameter which is related to de- termine the various correction factors as shown in fig3.
carrier frequency(fc):150 MHZ<fc<1500 MHZ
The effective base station antenna height(htr) :30m<htr <200m
The effective mobile antenna height(htt ):1m<htt <10m
The transmitter-receiver distance(D): km
The correction factor for effective mobile antenna height a(htt )
This model gives the better result in urban and suburban area but in the rural areas its efficiency decreases.This model is not suitable for personal communication systems.

2.3 ECC 33 Model

The ECC model is electronics communication system devel- oped for fixed wireless access system.The path loss model is defined as

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PLECC (db)=Asf +Amb -Gd -Gs
Asf , Amb , Gd and Gs are the free space attenuation, the basic medium path loss, the BS height gain factor and the terminal height gain factor.
Asf =92.4+20 log10 (d)+20 log10 (f)
Amb =20.41+9.83 log10 (d)+7.894 log10 (f)+9.56[log10 (f)]2
Gd =log10 (ha /200){3.958+5.8[log10 (d)]2
And for medium city environments
Gs =[42.57+13.7 log10 (f)[log10 (hc )-0.585] Where
f is the frequency in GHZ,d is the distance between transmitter
and receiver in km,ha is the BS antenna height in meters and hc is the CPE antenna height in meters. The ECC 33 model
compared the medium city data with the suburban and urban

2.4 COST- 231 Model

The COST-231 hata model extended hata’s model for use in the 1.5-2MHZ frequency range. This model is used in base station antenna is above the roof tops and is widely used in radio transmission in mobile telephony. The model is ex- pressed in terms of the following parameters
PL231 (db)=46.3+33.9log10 (fc )-13.28log10 (hbh )-a(hmh )+44.9-
6.55log10 (hbh )+Cc
PL 231 (db)=46.3+33.9log10 (fc )-13.28log10 (hbh )-a(hmh )+44.9-
6.55log10 (hbh )+Cc
Cc =0 (for medium city and suburban areas)
=3(for meteropolitan areas) Carrier frequency(fc )=1.5-2MHZ
BS antenna height(hbh )=30-200m MS antenna height(hmh )=1-10m Transmission distance(D)=1-20km

2.5 LEE Model

Lee path loss model is known more of a “North American
Model”.Lee model is based on flat terrain.
An error will take place when the model is applied to a non-
terrain.The propagation path loss will be calculated as:
PLLEE (db)=124+30.5log10 (d0 /d00 )+10k log10 (fc /f cc )-a0
d is in km, fc and fcc is in MHZ,k=2 for fcc <450MHZ and in suburban/open area and 3 for fcc >450 MHZ and in urban ar-
ea,doo =1.6 km.fc is transmitted frequency,do is the transmitter- recevier distance and a0 is the correction factor to account for BS and MS antenna heights.

2.6 Walfish And Bertoni Model

A model which using the diffraction to predict the avg. signal strength at a street level is known as walfish- bertoni model.
PL W-B (db)= I 0 R2 I1
I0 is the free space path loss for isotropic antennas, R2 gives the signal power reduction due to buildings which provides
images at receiver at street level, and I1 is based on signal loss from the rooftop to the street due to diffraction.
The model reduces the path loss in three factors:- (i)free space loss
(ii)loss along the building
(iii)loss down at the street along

2.7 Longley Rice Model

This Longley rice model is a radio propagation model.This model is also known as ITS irregular terrain model operates in two modes.First modes is path specific parameter and second is area mode prediction.
The Longley rice model is generally used for point to point
communication in frequency range of 40MHZ to 100MHZ in
different regions. This model is not use for mobile communi-
cations. The one shortcoming is that it does not count the ac- count of building and forest or foliage.

2.8 Standard University Intersim Model

The proposed standards for the frequency bands below
11GHZ contain the channel developed by standard university,
namely the SUI models[7]. The SUI models are considered into
three types of terrains, namely X,Y,Z. Type X is associated with maximum path loss and is appropriate for hilly terrain with moderate to heavy foliage densities. Type Z is associated with minimum path loss and applies to flat terrain with light tree densities. Type Y is characterized with either mostly flat terrains with moderate to heavy tree densities or hilly terrains with light tree densities. The path loss equation with correc- tion factor is
PL SUI (db)=α+10βlog10 d0 /d00 +Aa +Bb +C for d0 >d00
d0 is the distance between the AP and the CPE antennas in meters,d00 =100m and C is a log normally distributed factor that is used to account for the shadow fading owing to trees and other clutter and has a value between 8.2db and 10.6 db.
α =20 log10(4πd00 /λ)
β=x-ybh +z/hb
Where bh is the base station height above ground in meters and should be between 10 m and 80 m.For a given terrain type

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the path loss exponent is determined by hb .

2.9 Egly Propagation Model

Egly propagation model is frequency range approximately 50 feet in hill areas. Egli is based on measured propagation paths and then reduced to mathematical model[7]. In case of Egli, the model consist of propagation path equation
PLEG =117+40log10 d+20log10 f-20log10 (ht -hr ) Where
PLEG is attenuation in db(between dipole),d is the path dis- tance in miles,f is the frequency in mega hertz, ht is the trans- mitter antenna height above ground level(in feet) ,hr is the receiver antenna height above ground level(in feet)
The free space loss between half wave dipole antenna(in db) is
PLFS =32.27+20logd+20logf
To isolate the propagation of the loss
=84.73+20log10 d20log(ht *hr )
Egli propagation model is applicable only on short over water and very flat barren land paths and it is not applicable on foli-
age area.

2.10 Cost-231 Walfish-Ikagami Model(W-I)

This model is combination of two model first is J. Walfish and f.Ikegami model. This is most suitable for flat suburban and urban areas.This model is most suitable for flat suburban and urban ares. Among other models like hata model this model is more precise path loss model. This is a result of additional parameters introduced which characterized in a different en- vironments. So for LOS condition the path loss equation is
PLCOST-231 LOS=42.6+26 log10 D+20 log10 F For NLOS condition
PLCOST-231 NLOS= {PL FSL +PL RTS +PL MSD (for urban and suburban)
{PL FS (if PL RTS +PL MSD >0)
PL FSL =free space loss
PL RTS =roof top to street diffraction
PL MSD =multiscreen diffraction loss.


This model is used the multiple knife edges to compute the diffraction loss. It defines the new apperature at the point where the line of sight from two antenna crosses.[7]


This model is similar to bullington model but the major differ- ence is that in Epstein model it takes to draw line of sight be- tween relevant obstacles and add it to the diffraction loss at each obstacles.

3 Conculsion

In this paper we surveyed the different types of propagation
model with their path loss equation . Some propagation path loss model used in urban, suburban while some is used in ru- ral areas.For example Hata, okumara model are better in sub- urban area and the Longley rice model in rural areas.The ac- curacy of evey model in any given condition will depend on the suitability among parameter required by the model.The Hata okumara model has widespread application in open en- vironment but is severely limited in built up areas.The path loss of okumara,Hata and cost 231 model decrease as the transmitter antenna height and received antenna height but increase as the transmission distance.The okumara model is short path loss whereas the cost 231 model is largest path loss.


[1] Purnima k. sharma, R.k.singh “cell coverage area and link budget calculation in GSM system” international journals of modern en-

ginerring research(IJMER) vol2,issue2 Mar-April 2012.

[2] Dinesh Sharma, Purnima k.sharma, Vishal Gupta ,R.k.singh “A survey

on path loss model used in wireless communication model used in wireless communication system design” in IJRTE vol3 no2 in 2010.

[3]Vishal Gupta,S.c.sharma,M.C.bansal“Fringe area path loss correction factor for wireless\communication ” in IJRTE vol1,no2,may 2009.

[4]Purnima k.sharma,R.k.singh “comparative study of path loss models depends on various parameter.”in IJEST vol3,no6 in june 2011.

[5]Tushar Saxena, J.S.Jadson “Review on 2G,3G,4G radio planning” in

international journals of engineering,business and enterprise applica- tions in september –november 2013 pp 84-89.

[6]Theodre S.Rapport “wireless communications” pearson edition second edition.

[7]Pooja prajesh and R.K.singh “A survey on various propagation model

for wireless communication.”[5TH IEEE[ICACCT-2011] ISBN 81-87885-


[8]H.R.Aderson “Fixed broadband wireless system design” john wiley &

co. 2003.

[9]S.Ranvier(2004,November 23) path loss models(online) available. pdf.

[10]Hemant kumar Sharma, sanjeev Sharma, Pandey “Survey of propaga-

tion models in wireless network.”

[11]Yuvraj singh“Comparison of okumara,hata and cost 231 models on the

basis of path loss and signal strength” international journals of com- puter applications(0975-8887) volume 59-No.11,December 2012.

[12]V.erceg L.J.Greenstein,et al“An empirically path loss model for wire- less channels in suburban environment ”IEEE journals on selected ar- eas of communications,vol 17 pp1205-1211.

[13]Abhishek keny,Jigar shah,vivek mayuranathan,yash bhautt “Com- parision between propagation models for wireless applications.”

[14]T.Schwengler(2011,august) wireless and cellular communica- tion(online) available:-


[15]Vishal Gupta, Sandip Vijay and S.C.Sharma “Efficient path loss pre-

diction in mobile wireless communication nework. ”

[16]A.A Moinudin and S.Singh “Accurate path loss prediction in wireless

environment”the institution of engineers(india) volume 88,July

2007,Pp:- 09-13.

[17]Y.h.Guang Yang-Han lee,Hsien-wei tseng ming hsuen chuang, Jheng

yao Lin,chin wei su“ comparision propagation path loss mod- els”IEEE1802.16 m-07/121,call for comments,2007.

[18]V.S.Abhaywardhana/I.J.wasswell,D.crosby,M.P.Sellars,M.G.Brown“C omparision of empirical propagation path loss model for fixed wire- less access systems”IEEE conference 2005.

[19] Purnima.k.Sharma et. Al“Comparative Analysis of propagation path loss models with field measured data ” international journals of engi- neering science and technology vol2(6) 2010 2008-2013.

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ISSN 2229-5518

[20] H.K.Sharma,S.Sahu,S.Sharma, “Enchanced cost 231 W.I. Propagation model in wireless network”international journal of computer applica- tions(0075-8887)volume19-no.6,april 2011.

[21]Sagar Patel ved vyas Dwivedi and Y.P.kosta “A parameter characteri-

zation and comparactive study of okumara and hata propagation loss prediction models for wireless environment” Number4(2010).

[22]R.Mardani and K.F.Kwan “optimization of hata propagation predic- tion model in suburban area in Malaysia” progress in electromagnetic research c,vol.13,91106,2010.

[23]Nagendra and Amit kumar “ CSP algorithm in predicting and opti- mizing the path loss of wireless empirical propagation models” inter- national journal of computer and electrical engineer- ing,vol.1,no4,October,2009.

[24]T.K.Sarkar,Z.Ji,K.Kim,A.Madour & M.S.Palma “A Survey of various

propagation models for mobile communication” IEEE antennas and propagation magazine,vol.45,no.3,june 2003.

[25]Z.Nadir & M.Idrees ahmad “Path loss determination using okumara- hata model and cubic regression for missing data for oman”,proceeding of IMECS,vol.2,2010.

[26]C.Akkash “ Methods for path loss prediction”,Report 09067,ISSN


[27]Dinesh Sharma,R.K.Singh “ The effect of path loss on Qos at NPL” International Journal of Engineering Science and technology vol.2(7),2010,3018-3023.

[28]Vishal Gupta,SANDIP Vijay and S.C.Sharma “ Efficient path loss pre-

diction in mobile wireless ommunication network”,ISN2008,Feb. 22-


[29]Thomas kurner “ propagation prediction models” chapter 4pp115-


[30]P.Schneider, F.Lambrecht & A.Baier “Enchancement of the okumara-

hata propagation using detailed morphological and building da- ta”,IEEE,1996.

Authors Biography

M.s Archana was born on 15th feb 1990 in narnaul.,Haryana
( India). She is pursuing .degree in electronics & com-
munication Engineering from surag collage of engineering from MDU University(Rohtak), India. She has published sev- eral research papers in national and international jour- nals/conferences.
Mr.J.P.Sharmawas born on 3rd July 1985 in Gangapur city of Rajasthan (India).He received his Degree in Digital communication from Rajasthan Technical University, Raja- sthan, India. He is associate member of the Indian Society For Technical Education. He has published several Research pa- pers in national and international journals/conferences.His present research interest is in communication and signal pro- cessing.
Dr.Dinesh Sharma was born on 5th Dec 1982 in narnaul dis- trict mohindergarh of Haryana( India). He received his Ph.D. Degree from UTU, Dehradun(INDIA) and degree in communication engineering in SHOBHIT university, Meerut, India.He ia a associate member of the IETE.He has published several Research papers in national and international jour- nals/conferences. His present research interest is in signal processing and wireless communication.
Mrs.Purnima K Sharma was born on 2nd June1983 in Eluru,
Andhra Pradesh (India).She received her degree in communication and Signal Processing engineering from NAGARJUNA University(A.P) India.She ia a associate mem- ber of the IETE.She has published several Research papers in national and international journals/conferences. Presently she is research scholar at UTU dehradun (INDIA).Her present research interest is in image processing and wireless commu- nication

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