User's Manual Part 5

ROI-S05749 SYSTEM SETUP
3-25
Using MTPC-ATPC
The ATPC Control System of the PASOLINK transmits the information on
the receiving level to the opposite station and controls the transmission
level of its local station in accordance with the receiving level of the
opposite station. Transmission level control can be used not only for
setting the same operation (ATPC-ATPC) between local station and
opposite station but also for operation in combination of stations with
different operations (MTPC-ATPC, ATPC-MTPC). The station set in
MTPC mode is not controlled by the information from opposite station but
is fixed in its transmitting output level.
Even if the station is set in the MTPC mode, the opposite station is likely
to be set in the ATPC mode. Therefore, setting the RX Threshold (ATPC
Threshold level) is required for controlling the transmission level of the
opposite station. Between the stations that are respectively set in the
MTPC mode, however, the setting is disabled.
The following is an example of operation between stations set in MTPC-
ATPC mode.
The transmitting level of station B is controlled so that the receiving level
of station A in the above figure reaches the RX Threshold set level (−50
dBm) set in station A. This method is used in station A for reducing the
level of interference to other route. As station A is set in the MTPC mode,
the transmitting level is kept unchanged.
An example of using MTPC-ATPC is shown below. As shown in the
figure, in the master station communicating with many substations, waves
gather from substations possibly causing interferences. Therefore,
substations must be set in the ATPC mode to minimize the diffraction
(interference) to other routes while reducing the receiving levels from
individual substations to the minimum. In substations, there is little
possibility of occurring interferences; therefore, the master station is set in
the MTPC mode to permit transmission at a constant level.
MTPC
(RX Threshold: −50 dBm)
ATPC
PASOLINK
ODU
PASOLINK
ODU
STATION A
STATION B