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A17.7.3
A17.7.3
For calculation of the path loss according to Recommendation ITU-R P.1546-1 Annex 8 the following procedure is followed:

1 Check rangeof application of the propagation model regarding time percentage, frequency, distance, and antenna height: 

     
    • Time percentage :
    •                           
    •                           1% £< pt £< 50 %
    • Frequency :                                     30 MHz £< f £< 3 000 MHz
    • Distance :
    •                                      
    •                                        0.001 km  £< d £< 1000 km
    • Transmitter antenna height :
    •            0 m < ht
    •            0 m £< ht £< 3000 m
    • Receiver antenna height :
    •     
    •                1 m £<
    • hr
    • hr £< 3000 m

 

2 Determination of lower and higher nominal percentages ptinf and ptsup:

...

4 If ht ³ 10 m: calculate field strength strength E(f= f, d, ht, hr, pt) 4) :

4.1) Calculation of the four following field strengths:

...

4.1.1) Calculate the dimensionless parameter k, function of the required transmitter height, ht:

             Image RemovedImage Added                                 (Eq. 218)

4.1.2) Determine from the following table the set of parameters a0 to a3, b0 to b7, c0 to c6 and d0 to d1 to be used according to nominal values of frequencies and time percentages:

 

Anchor
T085
T085
Table 85: Parameters a0 to a3, b0 to b7, c0 to c6 and d0 to d1

 

Frequency

100 MHz

600 MHz

2 000 MHz

pt %

50

10

1

50

10

1

50

10

1

a0

0.0814

0.0814

0.0776

0.0946

0.0913

0.0870

0.0946

0.0941

0.0918

a1

0.761

0.761

0.726

0.8849

0.8539

0.8141

0.8849

0.8805

0.8584

a2

-30.444

-30.444

-29.028

-35.399

-34.160

-32.567

-35.399

-35.222

-34.337

a3

90.226

90.226

90.226

92.778

92.778

92.778

94.493

94.493

94.493

b0

33.6238

40.4554

45.577

51.6386

35.3453

36.8836

30.0051

25.0641

31.3878

b1

10.8917

12.8206

14.6752

10.9877

15.7595

13.8843

15.4202

22.1011

15.6683

b2

2.3311

2.2048

2.2333

2.2113

2.2252

2.3469

2.2978

2.3183

2.3941

b3

0.4427

0.4761

0.5439

0.5384

0.5285

0.5246

0.4971

0.5636

0.5633

b4

1.256E-7

7.788E-7

1.050E-6

4.

323E

323E-6

1.

704E

704E-7

5.

169E

169E-7

1.677E-7

3.126E-8

1.439E-7

b5

1.775

1.68

1.65

1.52

1.76

1.69

1.762

1.86

1.77

b6

49.39

41.78

38.02

49.52

49.06

46.5

55.21

54.39

49.18

b7

103.01

94.3

91.77

97.28

98.93

101.59

101.89

101.39

100.39

c0

5.4419

5.4877

4.7697

6.4701

5.8636

4.7453

6.9657

6.5809

6.0398

c1

3.7364

2.4673

2.7487

2.9820

3.0122

2.9581

3.6532

3.547

2.5951

c2

1.9457

1.7566

1.6797

1.7604

1.7335

1.9286

1.7658

1.7750

1.9153

c3

1.845

1.9104

1.8793

1.7508

1.7452

1.7378

1.6268

1.7321

1.6542

c4

415.91

510.08

343.24

198.33

216.91

247.68

114.39

219.54

186.67

c5

0.1128

0.1622

0.2642

0.1432

0.1690

0.1842

0.1309

0.1704

0.1019

c6

2.3538

2.1963

1.9549

2.2690

2.1985

2.0873

2.3286

2.1977

2.3954

d0

10

5.5

3

5

5

8

8

8

8

d1

-1

1

2

1.2

1.2

0

0

0

0

 

 

4.1.3) Calculate the unblended to maximum value field strength, Eu, at the distance, d, and transmitting height, ht, as follows:

                                                                           Image RemovedImage Added             (Eq. 219)

where: Image RemovedImage Added

and: Image RemovedImage Added

and: Image RemovedImage Added

where: Image RemovedImage Added

 

where: Image RemovedImage Added

 

and: Image RemovedImage Added

 

4.1.4) Calculate the blended to the free space value of field strength, Eb, at the distance, d, and transmitting height, ht, as follows:

                                                                               Image RemovedImage Added     (Eq. 220)

...

Qinf       =Qi (ptinf/100)

Qsup  = Qi (ptsup /100)

Einf    = E(f, d, ht, hr, ptinf)

...

The field-strength values given by the land curves and associated tabulations in this recommendation are for a reference receiving antenna at a height, R (m), representative of the height of the ground cover surrounding the receiving/mobile antenna, subject to a minimum height value of 10 m.

The SEAMCAT always assumes the height of local clutter R , depending on the propagation environment set in the model selection window:

Anchor
T086
T086
Table 86: Default clutter height in the

...

ITU-R P1546-1 model (when clutter height option not activated)

 

Selected environment

Assumed height of local clutter, m

Rural

10

Sub-urban

10

Urban

20

 

 

If the receiving antenna height, hr (m), is different from the assumed R value, as shown in Table 86 , a correction shall be added to the field strength taken from the curve.

...

where J(n) is given by :

              Image RemovedImage Added                             (Eq. 227)

...

                                                 Image RemovedImage Added

Image RemovedImage Added

            

                                                                       C0 = 2.515517

...

                                                                                                                             Image RemovedImage Added

where:

                      Df:        frequency-dependent term

                     =           Image RemovedImage Added               km                                                                              

...

                     =        Image RemovedImage Added                       km                                                                              

...