Antenna System Supervision RBS 6000

Contents

1 Overview

This document describes the supervision of cables and antenna systems in RBS 6000, which uses Wideband Code Division Multiple Access (WCDMA) technology.

2 Antenna System Hardware Units

This section describes the hardware units of the antenna system.

The hardware units are as follows:

Antenna System Controller (ASC)

Tower Mounted Amplifier (TMA)

DESCRIPTION 14/1551-LZA 701 6003 Uen F

1 Overview 2

Antenna System Hardware Units

2.1 ASC 2.2 TMA 2.3 ATMA 2.4 RETU 2.5 ARETU 2.6 RIU 3

Antenna System Configuration

4

Supervision Methods

4.1 Antenna Supervision Activation and Tuning 4.2 Antenna Supervision 4.3 Auxiliary Units DC Supervision 5

Antenna System Configurations and Supervision Overview

5.1 No Auxiliary Units 5.2 ASC/ATMA 5.3 ASC/ATMA and ARETU/RETU 5.4 RIU and ARETU/RETU 5.5 TMA 5.6 TMA, RIU and ARETU/RETU 5.7 TMA with External Power Supply 6

Supervision Overview

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DisclaimerThe contents of this document are subject to revision without notice due to continued progress in methodology, design and manufacturing. Ericsson shall have no liability for any error or damage of any kind resulting from the use of this document.

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Remote Electrical Tilt Unit (RETU)

Remote electrical tilt Interface Unit (RIU)

Also supported is the Antenna Interface Standards Group/3rd Generation Partnership Project (AISG/3GPP) defined components ATMA and ARET.

Note: This document only describes solutions with ASC and the configurations based on the AISG 2.0/3GPP specifications are neither described, nor handled or tested by Ericsson.

2.1 ASC

The ASC is an auxiliary unit with the following main functions:

Amplifying uplink signals

The uplink amplification is set with respect to the feeder attenuation.

Supplying power to a ARETU/RETU

Supervising the antenna

ASC communication passes through branch A. For more information on the ASC, see ASC Description

2.2 TMA

The TMA has the following characteristics:

Offers uplink amplification

Powered by the RU through the feeders

Can also be powered by an external power source

Has no communication

2.3 ATMA

The ATMA is an alternative to ASC and TMA and has the following characteristics:

Amplification of uplink signals

The uplink amplification is set with respect to the feeder attenuation.

RS 485 interface towards the RBS.

Power supply to an ARETU.

No supervision of the antenna.

The ATMA can be used when both TMA and Remote Electrical Tilt (RET) functionalities are needed.

2.4 RETU

The RETU contains a communications interface and a step motor to engage the tilt mechanism of the antenna.

For more information on the RETU, see the RETU documentation in the RBS Site Products CPI library.

Using RETU in an RU configuration:

The RETU is powered by the RU and is supervised by the ASC.

The RETU is connected to the ASC, and communicates with the RBS through antenna branch A.

In systems with no ASC, the RETU is powered by the RU and is supervised by the RIU that is connected to antenna branch A, but is however unable to issue alarms.

2.5 ARETU

The ARETU is an alternative to the RETU. As in the case of the RETU, the ARETU contains a communication interface and a motor to engage the antenna tilt mechanism. The ARETU includes an RS485 interface as specified in the AISG 2.0/3GPP standard. However, from a software point of view there is no difference between a RIU/ARET configuration and an ARET with included modem.

Using ARETU in an RU configuration:

The ARETU is powered by the RU.

The ARETU can be connected to the ASC, and communicates with the RBS through antenna branch A.

The ARETU can also be used without ASC.

In this case, the ARETU is powered by the RU and is supervised through the RIU that is connected to the antenna branch A, but is however unable to generate alarms.

If the RIU is not present, the supervision is made directly from the RBS through the antenna branch A.

The ARETU is supervised through the ATMA.

2.6 RIU

The RIU is an interface to the RETU used in macro RBS antenna systems where ASC is not used. The RIU is used for transfer of DC supply and for communication between the RBS and the RETU/ARET.

The RIU is installed close to the antenna and connected to antenna branch A, to the ANT A antenna connector, and to the RETU/ARET.

The RIU can also be used in antenna systems with a TMA and has a DC supply switch for transferring DC power supply to the TMA. In this case, the RIU is connected to antenna branch A, to the RBS A TMA connector, and to the RETU/ARET.

3 Antenna System Configuration

The antenna system is configured in Element Manager Wizards – Site Equipment Wizard.

For information on how to calculate the feeder attenuation and the electrical delay, see the antenna system test instruction in the RBS Site Products CPI library..

Note: The total attenuation and delay values depend on the values for the feeder and jumper cables in the antenna systems. See Section 5.

See also Managed Object Model (MOM) RBS, sections Antenna Feeder Cable Parameters and Antenna Jumper Cable Parameters respectively.

4 Supervision Methods

Depending on antenna system configuration, different supervision methods are used. This is described in Section 4.2.

These methods are selected by the system, not by the user.

4.1 Antenna Supervision Activation and Tuning

By default, no antenna supervision is activated and the supervision threshold parameter is set to 0 (percent).

Antenna supervision on applicable sector is activated by entering antenna supervision threshold values in the antenna branch configuration page when running the Site Equipment wizard. This is usually performed during the Site Equipment Configuration. See Element Manager Wizards.

Antenna supervision can be deactivated by setting the supervision threshold to 0.

When activated, supervision on both branch A and branch B are activated and default value for the attribute is set to 80. The branches are then tuned separately.

The attribute value for all branches with an ASC must be set to 10.

Change the value in the RBS Element Manager (EM) by modifying the attribute antennaSupervisionThreshold on the AntennaBranch Managed Object (MO) as shown in Figure 1.

Figure 1 Sector Antennas Expanded

For information on how to calculate the supervision threshold value, see Managed Object Model (MOM) RBS, section Antenna Branch Parameters.

4.2 Antenna Supervision

This section describes methods for supervising the antenna.

4.2.1 DC Resistance

3 V DC is sent by the Radio Unit (RU). The resistance must be below the threshold value, or an alarm is generated. Antenna systems supervised by this method require antennas with a DC short between the inner and the outer conductor, that is, tuned coil.

DC resistance is used when there are no auxiliary units between the RBS and the antenna. The default attribute value can be changed by the user.

For information on how to calculate the threshold value, see Managed Object Model (MOM) RBS.

In cases where branch B is not used, the value for branch B is set to 0 by the user.

4.2.2 Voltage Standing Wave Ratio

Voltage Standing Wave Ratio (VSWR) detection requires a TX signal. A branch with no TX signal cannot be supervised by VSWR detection.

The ASC supervises the antenna by detecting the VSWR on branch A and branch B when they are used for TX. The threshold setting is irrelevant for a branch that is not used for TX, and supervision will always be switched off.

The TMA does not have antenna supervision.

The RUs supervise the antenna by detecting the VSWR on branch A only (when there is no ASC). It is recommended to set the attribute value to 10 in the Site Equipment wizard.

The B branch of the RU with no TMA is recommended to be set at 80 for DC supervision. Where branch A or branch B, or both is not used for supervision, the value for branch A or branch B, or both is set to 0 by the user, which is equivalent to deactivation.

This means that where the RU detects VSWR on branch A and 3 V DC on branch B, the attribute value for branch A should be changed to 10 by the user. The attribute value for branch B remains at 80.

4.3 Auxiliary Units DC Supervision

This section describes methods used by the RU to supervise the ASC and the TMA.

4.3.1 DC Current

The RU supervises ASC/TMA DC consumption. An alarm is generated if DC consumption is too high or too low.

5 Antenna System Configurations and Supervision Overview

This section describes the different antenna system configurations. How the supervision of the antenna system is performed depends on whether auxiliary units are used.

Note: For configurations with auxiliary units between the RU and the antenna, these units are not mentioned in the tables for the VSWR supervision method. The RU supervises the whole path towards the antenna and the alarm does not indicate which unit is causing the alarm.

5.1 No Auxiliary Units

This section describes antenna systems with no auxiliary units as shown in Figure 2.

Figure 2 Antenna System with No Auxiliary Units

5.1.1 Supervision

This section describes antenna system supervision with no auxiliary units and possible supervision methods are described in Table 1.

(1) "RU → Antenna" is short for "RU supervision of the antenna

5.2 ASC/ATMA

This section describes antenna systems with ASC/ATMA as shown in Figure 3.

Figure 3 Antenna System with ASC/ATMA

Branch A contains control signalling to the ASC.

5.2.1 Supervision

This section describes antenna systems supervision with ASC/ATMA and possible supervision methods are described in Table 2.

(1) The alarm is controlled by the AntennaBranch::lowCurrentSupervision MO attribute (2) Supervision only when using ATMA

Table 1 Possible Supervision Methods

Supervision Type Method Alarm Generated

RU → Antenna(1) DC resistance AntennaSystemProblem

RU → Antenna VSWR

Table 2 Possible Supervision Methods

Supervision Type Method Alarm Generated

RU → ASC – CommunicationLostWithAsc

DC current FeederCurrentTooHighBranchA (or B) FeederCurrentTooLowBranchA (or B) (1)

RU → Antenna(2) VSWR AntennaSystemProblem

ASC → Antenna ATMA – –

5.3 ASC/ATMA and ARETU/RETU

This section describes antenna systems with ASC/ATMA and ARETU/RETU as shown in Figure 4.

Figure 4 Antenna System with an ASC and an ARETU/RETU

Branch A contains communication signals to the ASC and the RETU.

5.3.1 Supervision

This section describes antenna systems supervision with ASC/ATMA and ARETU/RETU and possible supervision methods are described in Table 3.

(1) The alarm is controlled by the AntennaBranch::lowCurrentSupervision MO attribute (2) Supervision only when using ATMA

5.4 RIU and ARETU/RETU

This section describes antenna systems with RIU and ARETU/RETU as shown in Figure 5.

Table 3 Possible Supervision Methods

Supervision Type Method Alarm Generated

RU → ASC/ATMA DC current

CommunicationLostWithAsc FeederCurrentTooHighBranchA (or B) FeederCurrentTooLowBranchA (or B)(1)

ASC → ARETU/RETU RetPortCurrentTooHigh

RU → Antenna(2) VSWR AntennaSystemProblem

ASC → Antenna RU → ARETU/RETU – CommunicationLostWithRet

Figure 5 Antenna System with RIU and RETU

Branch A contains communication signals to the RIU and the RETU.

5.4.1 Supervision

This section describes antenna systems supervision with RIU and RETU and possible supervision methods are described in Table 4.

(1) On branch B only (2) The alarm is controlled by the AntennaBranch::lowCurrentSupervision MO attribute

5.5 TMA

This section describes antenna systems with TMA as shown in Figure 6.

Table 4 Supervision Methods

Supervision Type Method Alarm Generated RU → Antenna DC resistance(1) AntennaSystemProblem

RU → RIU-RETU DC current FeederCurrentTooHighBranchA

FeederCurrentTooLowBranchA(2)

– CommunicationLostWithRet RU → Antenna VSWR AntennaSystemProblem

Figure 6 Antenna System with a TMA

An antenna system with a dual branch TMA, supporting both branches. A single-branch TMA supports only one branch per TMA. No branch contains any communication.

5.5.1 Supervision

This section describes antenna systems supervision with TMA and possible supervision methods are described in Table 5.

(1) The alarm is controlled by the AntennaBranch::lowCurrentSupervision MO attribute

5.6 TMA, RIU and ARETU/RETU

This section describes antenna systems with TMA, RIU, and ARETU/RETU as shown in Figure 7.

Table 5 Supervision Methods

Supervision Type Method Alarm Generated

RU → TMA DC current FeederCurrentTooHighBranchA (or B) FeederCurrentTooLowBranchA (or B) (1)

RU → Antenna VSWR AntennaSystemProblem

Figure 7 Antenna System with TMA, RIU, and RETU

Branch A contains communication signals to the RIU and the RETU.

5.6.1 Supervision

This section describes antenna systems supervision with TMA, RIU, and RETU and possible supervision methods are described in Table 6.

(1) The alarm is controlled by the AntennaBranch::lowCurrentSupervision MO attribute

5.7 TMA with External Power Supply

This section describes antenna systems with TMA and external power supply as shown in Figure 8.

Table 6 Supervision Methods

Supervision Type Method Alarm Generated RU → RIU-TMA DC current LnaFailureBranchA (or B)

FeederCurrentTooHighBranchA (or B) FeederCurrentTooLowBranchA (or B) (1)

RU → Antenna VSWR AntennaSystemProblem

RU → ARETU/RETU DC current FeederCurrentTooHighBranchA – CommunicationLostWithRet

Figure 8 Antenna System with TMA and with External Power Supply

No branch contains communication.

5.7.1 Supervision

This section describes antenna systems supervision with TMA and external power supply and possible supervision methods are described in Table 7.

6 Supervision Overview

Table 8 lists the various supervision methods and when they can be used.

(1) ASC supervises both branch A and B, but supervises only the antenna branch where there is an active TX signal.

Table 7 Supervision Methods

Supervision Type Method Alarm Generated RU → TMA – – RU → Antenna VSWR AntennaSystemProblem

Table 8 Antenna System Supervision Overview

Auxiliary Units Used

Supervision methods Supervision CommunicatDC Resistance VSWR on branch A DC Current Alarms from

No Units RU → Antenna RU → Antenna - - -

ASC/ATMA -

ASC → Antenna(1)

RU → Antenna

RU → ATMA

RU → ASC ASC RU → ASC/AT

ASC and ARETU/RETU -

ASC → Antenna (1)

RU → Antenna

RU → ASC/ATMA

ASC → ARETU/RETU

ARETU/RETU

ASC

RU → ARETU/R

RU → ASC/AT

RIU and ARETU/RETU RU → Antenna RU → Antenna RU → RIU-

ARETU/RETU ARETU/RETU RU → ARETU/R

TMA - RU → Antenna RU → TMA TMA -

TMA, RIU and ARETU/RETU - RU → Antenna

RU → TMA

RU → ARETU/RETU TMA RU → ARETU/R

TMA w External Power - RU → Antenna - - -

Antenna System Supervision RBS 6000