Huawei OptiX RTN 980L V100 Quick Installation Manual page 15

Installation Scenarios
7
Height Difference Between the Main Antenna and SD Antenna Being Greater Than 20 m (66 ft)
 The waveguide length difference between the BU-to-main antenna and BU-to-SD
antenna must less than 25 m (82 ft).
 If SD is configured and the height difference between the main antenna and SD
antenna is greater than 20 m (66 ft), the BU must be installed at the middle position
between the two antennas, and elliptical waveguides are used to connect the BU and
antennas. Usually, a flexible waveguide is used to connect the BU and the upstream
elliptical waveguide.
Main antenna
BU/RFU
SD antenna
When the elliptical and flexible waveguides are connected to the SD antenna, they can
be replaced by SD cables. This replacement does not apply to the main antenna. You
are advised to use the elliptical and flexible waveguides for both the SD and main
antennas.
Example (Single-Polarized Antennas)
Δh > 20 m (66 ft )
Flexible
waveguide
Wave guide
Length ≤ 25 m
(82 ft )
Elliptical
waveguide
Flexible
waveguide
Wave guide
Length ≤ 25 m
(82 ft )
Elliptical
waveguide
Flexible
waveguide
14
Example (Dual-Polarized Antennas)
Flexible
waveguide
Elliptical
waveguide
Flexible
waveguide
Elliptical
waveguide
Flexible
waveguide
Wave guide
Length ≤ 25 m
(82 ft )
Wave guide
Length ≤ 25 m
(82 ft )