Radwin 2000 C PLUS, User Manual

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RADWIN 2000 C Plus User Manual Release 3.5.70 11 ‐ 1
Chapter 11:
Using the RADWIN GSU
What is it for
The GPS ‐ based synchronization unit (GSU) is designed to handle inter ‐ site interferences
under large ‐ scale deployment scenarios.
The GSU is an outdoor unit consisting of a small size enclosure, a GPS antenna and a PoE
device.
The GSU is connected to the HSS Unit using a standard HSS cable. It synchronizes the
transmission timing of multiple Hub ‐ Sites to the same clock source thus eliminating mutual
interference.
GSU Functionality
The GSU receives a synchronization signal from the GPS once per second. It distributes a
RADWIN proprietary synchronization signal to all other ODUs using the RS422 protocol and
the standard HSS mechanism, where the GSU acts as an HSM unit.
When the GSU doesn’t receive a synchronization signal from the GPS for 30 seconds, it moves
automatically to Self ‐ Generation mode and acts as a regular HSM unit, until the GPS recovers.
Typical GSU Scenarios
Independent Distributed Sites
In the scenario of Figure 11 ‐ 1 , we have multiple independent collocated sites, which may
interfere with each other. To meet this situation, we coordinate all of them using the GSU as
shown.
The GSU functions like “wide area HSS unit”, ensuring that all participating radios at the
locations marked GSU each transmit and receive at the same time.