RET Antennas

NodeB Antenna System User Guide-RET

5 Control of RET Antennas

5

Control of RET Antennas

About This Chapter Huawei base station integrates the functions of controlling RET antennas. It manages the STMA and RCU as internal components. 5.1 Control of Macro Base Station RET Antennas The RET antennas of the macro base station station can be controlled by the method of Two methods can be used: SBT + RCU and STMA + RCU. 5.2 Control of DBS RET Antennas The DBS RET antennas can be controlled by three methods: direct connection through multicore cables, BT + SBT, and BT + STMA.

Issue 02 (2008-01-30)

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5.1 Control of Macro Base Station RET Antennas The RET antennas of the macro base station can be controlled by the method of Two methods can be used: SBT + RCU and STMA + RCU.

SBT + RCU Figure 5-1 shows the configuration of the SBT + RCU method. Figure 5-1 SBT + RCU

The procedure for adjusting the tilt of the RET antenna is as follows:

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1.

The M2000 or the LMT sends the control signals for the RET antenna to the base station.

2.

The NodeB modulates the control signals into OOK signals, and then transfers the OOK signals and the DC power to the SBT over the feeder.

3.

In the SBT, the DC power is directly forwarded to the RCU, and the OOK signals are demodulated and then are converted into RS485 signals before being forwarded to the RCU.

4.

When the RCU receives the RS485 signals, it runs the command as specified in the signals to adjust the antenna tilt.


Issue 02 (2008-01-30)



STMA + RCU Figure 5-2 shows the configuration of the STMA + RCU method. Figure 5-2 STMA + RCU

The procedure for adjusting the tilt of the RET antenna is as follows: 1.

The M2000 or the LMT sends the control signals for the RET antenna to the base station.

2.

The base station modulates the control signals into OOK signals, and then transfers the OOK signals and the DC power to the STMA over the feeder.

3.

In the STMA, the DC power is directly forwarded to the RCU, and the OOK signals are demodulated and then are converted into RS485 signals before being forwarded to the RCU.

4.


5.2 Control of DBS RET Antennas The DBS RET antennas can be controlled by three methods: direct connection through multicore cables, BT + SBT, and BT + STMA. Issue 02 (2008-01-30)


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NOTE

The common BT transmits DC signal and RF signal, and the OOK BT transmits DC signal, RF signal, and OOK signal. For the RET antenna system, the OOK BT must be used.

Direct Connection Through Multi-Core Cables When the distance between the RRU3801C and the RCU is less than 20 m, they are connected through multi-core cables. Figure 5-3 shows the direct connection through multi-core cables. Figure 5-3 Direct connection through multi-core cables

The procedure for controlling the RET antenna in this connection is as follows: 1.

The M2000 or the LMT sends the control signals to the BBU.

2.

The BBU transfers the control signals to the RRU3801C.

3.

The RRU3801C converts the control signals into RS485 signals, and then transfers the RS485 signals to the RCU over multi-core cables.

4.


BT + SBT When the distance between the RRU3801C and the RCU is more than 20 m, the system does not use the STMA. Instead, the BT + SBT connection is used. Figure 5-4 shows the BT + SBT connection.

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Figure 5-4 BT + SBT connection



2.


3.

The RRU3801C modulates the control signals into OOK signals, and then transfers the OOK signals and the DC power from the BT to the feeder through the control port.

4.

The OOK signals and the DC power are transferred to the SBT through the feeder. Then, the DC power is directly forwarded to the RCU. The OOK signals are demodulated and then converted into RS485 signals before being forwarded to the RCU.

5.

When the RCU receives the RS485 signals, it runs the command as specified in the signals to adjust the antenna tilt. NOTE

The 20 W RRU3801C is a product only belonging to NodeB V100R008. For the 40 W RRU3801C, the BT or the AISG coaxial cable is not required because the BT is integrated into the RRU3801C.

BT + STMA When the distance between the RRU3801C and the RCU is more than 20 m, and when the system uses the STMA, the BT + STMA connection is used. Figure 5-5 shows the BT + STMA connection.

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Figure 5-5 BT + STMA connection



2.


3.

The RRU3801C modulates the control signals into OOK signals, and then transfers the OOK signals and the DC power from the BT to the feeder through the control port.

4.

The OOK signals and the DC power are transferred to the STMA through the feeder. Then, the DC power is directly forwarded to the RCU. The OOK signals are demodulated and then converted into RS485 signals before being forwarded to the RCU.

5.

When the RCU receives the RS485 signals, it runs the command as specified in the signals to adjust the antenna tilt. NOTE

The 20 W RRU3801C is a product only belonging to NodeB V100R008. For the 40 W RRU3801C, the BT or the AISG coaxial cable is not required because the BT is integrated into the RRU3801C.

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Issue 02 (2008-01-30)

RET Antennas

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