Radwin 5000 HPMP User Manual page 221

Configuring the GSU
The permitted RFPs are also dependent on channel bandwidth and are color coded as fol-
lows:
You May use
RFP/Channel
Bandwidth
combinations
with this color
There is a further restriction: If there are two distributed sites transmitting to each other,
they must both use the same RFP. This requirement, together with use of shifted transmis-
sion phase (item 3 below), ensures that communicating distributed sites to not interfere
with each other by transmitting simultaneously.
Two GSU managed sites transmitting with shifted transmission phase and using the same
RFP, transmit one half a RFD apart (see
2. Setting the Tx Transmission Ratio
Since the GSU is always HSM, it must be able to cater for any combination of collocated
RADWIN 5000 HBSs and RADWIN 2000 ODUs. (See
allocation, shifted transmission phase becomes unavailable and you cannot "cascade" links
as described in step 1.
There is a further issue arising from changing the Tx Transmission Ratio for a sector.
The GSU always operates at 20 MHz CBW. Nevertheless, you may operate the sector using
a different CBW.
If you use a different sector CBW and set the GSU downlink transmission ratio too high, it
may cause the HBS to cease transmitting. The reason for this is that the HBS translates the
GSU transmission ratio to a higher uplink value, which may fall out of the allowable range
for the HBS CBW even though it looks normal at the GSU. This is a perfectly normal situa-
tion.
It is quite easy to find the downlink limit empirically. Here is an example, based on the
setup used in Chapter 4

To locate the maximum downlink limit for a sector:
1. Set the HBS CBW to 5 MHz.
2. Set the GSU transmission ratio to favour downlink like this:
At the HBS, it translates to this:
RADWIN 5000 HPMP User Manual
For these collocated radios
WinLink 1000 only
RADWIN 2000 only
WinLink 1000 and RADWIN 2000 together, RADWIN 5000 HBS with anything
None - unavailable
Figure 11-3
and later.
Release 3.3.30
above).
Chapter 10). If you use asymmetric
Chapter 11
11-9