User's Manual

MDR2400-SR, MDR5800-SR and Orion 5825-SR
Issue 10 Page 26
3 Planning
This chapter is aimed at management and planning staff to enable them to assess the
requirements for installing an MDR / Orion digital radio link.
3.1 System Type Selection
The system uses an Outdoor Unit with a type-N RF output for connection to a range of
antennas.
The MDR / Orion is aimed at FCC regulated markets.
Antenna polarization can used to co-locate multiple systems.
Antenna polarization can be used to overcome interference.
3.1.1 Antenna selection
The antenna type must be selected before the system is to be installed. The chosen
antenna must enable the system to operate with sufficient link fade margin without
excessive cost and allow the user’s ‘link availability requirements’ to be met.
The main consideration when selecting an antenna is antenna gain measured in dBi.
A path loss analysis is highly recommended to determine the antenna gain needed for
adequate fade margin. The table below shows antenna selection guidelines for some
configurations. The distances are calculated for a 20 dB link fade margin.
To reduce potential radio interference to other users, the antenna type and its gain
should be so chosen that the equivalent isotropically radiated power (EIRP) is not
more than that required for successful communication.
Table 8 MDR5800 Antenna Selection
Antenna Type Gain (dBi) MDR OU
Typical
Distance (Km)
Power level (dBm)
0.15 m Flat panel 18 9 24
0.3 m Flat panel 24 30 24
0.6 m Flat panel 28 80 24
Table 9 Orion 5850 Antenna Selection
Antenna Type Gain (dBi) MDR OU
Typical
Distance (Km)
Power level (dBm)
0.6 m Flat panel
(MT-20004)
28 80 24
Table 10 MDR2400 Antenna Selection
Antenna Type Gain (dBi) Distance (Km) Power level (dBm)
1.2 m Parabolic
Antenna
27 80 18