SMC Networks 2.4GHz/5GHz manual 31 ft 9.5 m 29 ft 8.8 m 60 ft 18.3 m

Bridge Link Planning

.

Total Link	Max Clearance	Approximate	Total
Distance	for 60% of First	Clearance for	Clearance
	Fresnel Zone at	Earth	Required at
	5.8 GHz	Curvature	Mid-point of
			Link
0.25 mile (402 m)	4.5 ft (1.4 m)	0	4.5 ft (1.4 m)
0.5 mile (805 m)	6.4 ft (1.95 m)	0	6.4 ft (1.95 m)
1 mile (1.6 km)	9 ft (2.7 m)	0	9 ft (2.7 m)
2 miles (3.2 km)	12.7 ft (3.9 m)	0	12.7 ft (3.9 m)
3 miles (4.8 km)	15.6 ft (4.8 m)	1.8 ft (0.5 m)	17.4 ft (5.3 m)
4 miles (6.4 km)	18 ft (5.5 m)	3.2 ft (1.0 m)	21.2 ft (6.5 m)
5 miles (8 km)	20 ft (6.1 m)	5 ft (1.5 m)	25 ft (7.6 m)
7 miles (11.3 km)	24 ft (7.3 m)	9.8 ft (3.0 m)	33.8 ft (10.3 m)
9 miles (14.5 km)	27 ft (8.2 m)	16 ft (4.9 m)	43 ft (13.1 m)
12 miles (19.3 km)	31 ft (9.5 m)	29 ft (8.8 m)	60 ft (18.3 m)
15 miles (24.1 km)	35 ft (10.7 m)	45 ft (13.7 m)	80 ft (24.4 m)
17 miles (27.4 km)	37 ft (11.3 m)	58 ft (17.7 m)	95 ft (29 m)

Note that to avoid any obstruction along the path, the height of the object must be added to the minimum clearance required for a clear radio line-of-sight. Consider the following simple example, illustrated in the figure below.

2.4m

20 m

Visual Line of Sight		Radio Line of Sight
	3 miles (4.8 km)
A	5.4 m	B	1.4 m
			9 m
17 m
			12 m

3-4