User's Manual

Liberator-V1000 User Manual Rev 04v05
Page 16 of 85 FBN Doc #: FBN-0125_04v05
3. SITE PLANNING
All installers must perform a full site inspection and plan carefully prior to the physical installation of a
Liberator-V1000 link.
This preparation must include:
•
Evaluating the most appropriate location for the installation of the terminal.
•
Identifying an appropriate mounting structure (wall or mast) for each terminal.
•
Planning the cable routing from the network component to the terminal.
3.1 Terminal Location
When selecting the best terminal location the following factors should be considered:
•
Accessibility (e.g. How to gain access to a roof)
•
Type of mounting (e.g. wall or pole)
•
Grounding connection point
•
Cable runs (max. 100 m / 328 ft)
•
Human safety: Exposure to Non-Ionising Radiation - The Liberator-V1000 terminal should be mounted so
that it is always separated from the location of any human being by a distance of at least 1 metre.
3.2 Line of Sight
To ensure a clear line of sight (LOS), there must be no obstructions between the two terminal locations: the
first Fresnel Zone should be completely clear of obstacles, see diagram below, with n=1. The required
clearance can be established visually, or by using the table below which gives the worst-case clearance at the
centre-point of the link. This table is valid for distances greater than about 4 metres from the radio terminal.
Note that this is the minimum clearance distance with perfect antenna alignment. It is recommended to use
the widest clearance distance around the LOS path as is practically possible.
Table 1 - Fresnel zone clearance for different ranges at 60GHz
Link Distance
Boundary Diameter (2F
1
)
100 m
328 ft
0.7 m
2.3 ft
200 m
656 ft
1.0 m
3.3 ft
400 m
1312 ft
1.4 m
4.6 ft
600 m
1968 ft
1.7 m
5.6 ft
800 m
2625 ft
2.0 m
6.6 ft
1000 m
3280 ft
2.2 m
7.3 ft
The figure below shows required clearance at close proximity to the antenna.
Figure 13 – Fresnel Zone Clearance at 60 GHz