User Manual

MDR2400 and MDR5800 User Manual

862-01881 Issue 8 Page 21

3 PLANNING

This chapter is aimed at management and planning staff to enable them to assess the

requirements for installing an MDR digital radio link.

3.1 System Type Selection

The MDR system uses an Outdoor Unit with a type-N RF output for connection to a

range of antennas.

The MDR is aimed at FCC regulated markets.

Antenna polarisation can used to co-locate multiple MDR systems.

Antenna polarisation can be used to overcome interference.

3.1.1 Antenna selection (MDR5800)

The antenna type must be selected before the MDR5800 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 5 MDR5800 Antenna Selection

Antenna Type Gain (dBi) 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

3.1.2 Antenna selection (MDR2400)

The antenna type must be selected before the MDR2400 system is to be installed.