Installation Chapter 5
RADWIN 2000 User Manual Release 2.6.40 5-11
For example with a dual antenna RADWIN 2000 can transmit at modulation of 64QAM and
FEC of 5/6 and get an air rate of 130 Mbps, compared to 65 Mbps with single antenna.
To work in this mode, each antenna port must be connected to an antenna, the RSS level in
both receivers should be balanced and a minimal separation between the antennas must be
maintained. (For example, by using dual polarization antennas a cross polarization separation
is attained).
Upon selecting Antenna Type as Dual, RADWIN 2000 automatically selects MIMO mode and
doubles the air rates.
RADWIN Manager indicates a case of unbalanced RSS between the two antennas.
Diversity Mode
Diversity Mode uses two antennas to improve the quality and reliability of the link. Often,
there is not a clear line-of-sight (LOS) between transmitter and receiver. Instead the signal is
reflected along multiple paths before if-ally being received.
Each such “bounce” can introduce phase shifts, time delays, attenuations, and even distor-
tions that can destructively interfere with one another at the aperture of the receiving
antenna. Antenna diversity is especially effective at mitigating these multi-path situations.
This is because multiple antennas afford a receiver several recordings of the same signal.
Each antenna will be exposed to a different interference envy-remnant. Thus, if one antenna
is undergoing a deep fade, it is likely that another has a sufficient signal. Collectively such a
system can provide a or-bust link.
Antenna diversity requires antenna separation which is possible by using a dual-polarization
antenna or by two spatially separated antennas.
Use Diversity instead of MIMO in the following situations:
• When the system cannot operate in MIMO Mode
• When one of the receivers has high interference compared to the second receiver (i.e.
the system is “unbalanced”)
• When you achieve higher capacity in Diversity Mode than in MIMO Mode
• When high robustness is of importance and the capacity of Diversity Mode is sufficient
(up to 25 Mbps full duplex)
Single Antennas at Both Sites
By selecting a single antenna at both sites the ODUs operate with a single radio that is con-
nected to the ANT 1 connector. The second radio is automatically shut down.
Single at One Site, Dual Antennas at the Other
In this mode one of the sites uses the ODU with a single antenna while the other site uses the
ODU with a dual antenna.
The advantages in this mode in comparison to using a single antenna in both sites are dou-
bled total Tx Power and additional polarization and/or space diversity (depending on the
polarization of installed antennas).
The air rates used in this mode are same as when using single antennas in both sites.
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