User manual

DTS Broadcast PDH Microwave Digital Radio User Manual
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7 Protection systems
7.1 General
Protection Systems are used to improve link reliability and availability. The L54 Protection
System may operate in one of the following modes, depending on customer requirements:
Hot Standby: Both terminals are powered on, and set to the same frequency, but one terminal’s
transmitter is muted to prevent interference.
Frequency Diversity: Both terminals’ transmitters are powered on, but use different frequencies to
avoid interference.
Space Diversity: The main and stand-by radios are set up in Hot Stand-by mode, but are
connected to their own antennas. The spatial separation of the antennas, combined with hitless receive
switching, provides the Space Diversity function on the receiving end of the link.
The ODU arrangements may use one antenna with a waveguide coupler, when the antenna is
larger, i.e. 1.8m. See figure 8-1.
Figure 7-1 Connectnig of Single Anttena/Dual ODUs
The IDU arrangement is similar for all four protection modes. The protection switch provides
connection between two IDUs, each of which connects to an ODU.