Page 102 - Integrated Wireless Propagation Models

80 C h a p t e r T w o

2.12. 1.2.3 Open Areas
1
L (dB) = L (urban) -4.78 (log.fJ + 18.33 logfc -40.94 (2.12. . 8)
where L(urban) is from Eq. (2.12.1.4), K = 2[log10(JMHj28)F+ 5 .4, and a(h2) = (l.l log10
jMHz - 0.7) h2 - 1 . 56 log10JMHz - 0.8.

2.12. 1.2.4 Hata's Formulas for fMHz = 800 M H z In this case, Eq. (2.12.1.3) atfMHz = 800 MHz
reduces to the following formula:
(2.12.1.9)

where
Type of Area K
Open 2 .52h - 3 . 7 7 28.26
2
Suburban 9.79
Me i u m-size to small city 0
d
Large city 0
Many methods were derived to improve the Hata model, including those of Allsebrook/8
21
0
2
Delisle et al./ Aurand and Post, and Akeyama et aP The Okumura-Hata model is
perhaps the most widely deployed model for macrocells as it is accurate and easy to
implement.
2 . 12.2 Cost 231 Hata Model
The European Co-operative for Scientific and Technical Research (EURO-COST) formed
the COST-231 working committee to develop an extended version of the Hata model
from 1500 MHz to 2 GHz.
The COST 231 model, sometimes called the Hata model PCS extension, is valid
between 1500 and 2000 MHz. The COST 231 median path loss is given by
L(dB) = 46.3+ 3 3.9log(JMHz)-13.82 l og(h1)-a(h2)
+ [ 44.9 - 6 .55log(h1) l og(d)+C (2.12.2.1)
where J M Hz is the frequency in MHz (1500 to 2 Ghz), h1 is the base station height in
meters, h2 is the mobile station height in meters, a(h2) is the mobile antenna height cor­
rection factor (see Eq. . 12.1.5 for suburban and Eq. 2.12. . 6 for urban), d is the link
1
1
distance in kilometer (1 to 20 km), C = 0 dB for medium-size cities or suburban centers
with medium tree density, and C = 3 dB for metropolitan centers.
The application of this model is restricted to macrocells where the base station
antenna is above the rooftops of adjacent buildings. It is not applicable to microcells
where the antenna height is low.

2 . 1 2.2.1 Extension of the Hata Model to Longer Distances
An empirical formula for modifying the Hata model from Eq. (2.12.1.4) to extend dis­
tances 20 to 100 km was developed by ITU-R and is given by
L1Tu (dB) = 69.55+ 26. 1 6 l og10 /MHZ -13.82 l og10 h1 -a(h2)
b
+ ( 44.9-6.55log10 �)(log10 dkm ) - K (2.12.2.2)