Handbook of Propagation Effects for Vehicular and ... - Courses

12-12
Propagation Effects for Vehicular and Personal Mobile Satellite Systems
blockage effects due to roadside obstacles and the presence of underpasses. The last
column of this table represents the number of experiments examined in arriving at the
indicated fade ranges. The numbers in parentheses represent the EERS values. Where
angle and/or frequency ranges are given, the EERS value is calculated at the lower
elevation angle and larger frequency (highest fade case). The system designer interested
in selecting a design fade margin may use the worst case fade or the mid-value depending
upon the individual system constraints. Alternate suggested fade margin levels may be
obtained using the indicated EERS values that are representative of roadside tree
shadowing where the tree density exceeds 55%.
Table 12-3: Fade level ranges at the 1% and 10% probabilities derived from measured
distributions which were culled in terms of frequency and elevation angle.
f (GHz) El (°)
Fade
P = 1% P = 10%
0.87 5 >30 (18) 21.5 (10.5) 1
0.87 15-20 13-18 (18) 5.5-8 (10.5) 2
0.87 30 14-20 (15) 6-10 (7.5) 1
0.87-0.893 45 7-15 (10.5) 2-7.5 (4) 2
0.87 60 3-12 (5.5) 2-5 (2.5) 1
1.5 19-26 11-21 (26) 3.5-16 (15.5) 5
1.5-1.55 30 17.5-25 (22) 8-13 (11) 2
1.5-1.6 40-50 2.5-32 (18) 1-20 (8) 7
1.3-1.6 50-60 5-18.5 (13) 2-7.5 (5) 7
1.3-1.6 80 8-12 2-3 3
2.05-2.09 18-21 >30 (31) >15 (18.5) 2
2.09-2.66 40-45 12-17.7 (22.5) 7-11.5 (10) 3
2.5-2.6 60 12-22.5 (11) 5-9 (10) 3
2.5-2.6 80 10.5-16 4.5-6 2
10.4 60 27.5-28 (17.5) 13-18.5 (7) 2
10.4 80 24-26 10.5-13 2
20 8 >25 (63) >25 (37) 1
18.7-20 30-38 21-40 (52) 9-33 (27) 4
20 46 8 to >30 (35) 2-30 (14.5) 3
20 54.5 28 (26) 15 (10) 1
12.7.2 Suggestions for Further Work
Number
Measurements at elevation angles smaller than 60° appear to be unavailable in the
frequency interval between 3 to 20 GHz and at frequencies greater than 20 GHz. Future
measurement programs should fill this gap.