User's Manual

Table Of Contents
BIRD DMR USER MANUAL
15
Revision 2
5.2.4 Advanced RF Config
Advanced mode in RF config menu gives user a possibility to control and fine tune the frequency
band edges, set up link symmetry, and self-oscillation protection.
Band edges control gives user a possibility to fine tune the set band width with 0-100 kHz up or
down of the actual set frequency band.
Link symmetry is a function that is mainly developed for usage in moving application setups, like in-
train, boats for example. What is does basically is that UL gain is controlled by the DL gain. When this
feature is activated, the repeater will reduce the gain in UL as in DL with the same symmetrical
pattern. The UL gain is determined by the actual automatically controlled gain used in DL. The
originally set gain difference between Uplink and Downlink is kept as originally set.
Link symmetry feature is used to minimize the amount of Noise level to the BTS and is developed
mainly for moving applications as mentioned above such as trains, boats for example when/if the
signal from the BTS fluctuates.