GBTS Product TOC Test Guide

GBTS Product TOC Test Guide

Issue 01

Date 2012-07-18

HUAWEI TECHNOLOGIES CO., LTD.

Issue 01 (2012-07-18) Huawei Proprietary and Confidential

Copyright © Huawei Technologies Co., Ltd.

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Copyright © Huawei Technologies Co., Ltd. 2012. All rights reserved.

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Notice

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Huawei Technologies Co., Ltd.

Address: Huawei Industrial Base

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mailto:[email protected]

GBTS Product TOC Test Guide About This Document



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About This Document

Change History

Date Revision Version Change Description Author

GBTS Product TOC Test Guide Contents



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Contents

About This Document .................................................................................................................... ii

1 Test Purpose ................................................................................................................................... 1

2 Test Method ................................................................................................................................... 2

3 Test Networking ............................................................................................................................ 3

4 Test Material .................................................................................................................................. 4

5 BTS Configuration and Precautions .......................................................................................... 5

5.1 Introduction ...................................................................................................................................................... 5

5.1.1 TRX Binding Relationship ...................................................................................................................... 5

5.1.2 Power of Various Channels ..................................................................................................................... 5

5.1.3 Dummy Burst Test .................................................................................................................................. 6

5.1.4 Impacts of OM Operations on a Power Test ........................................................................................... 6

5.1.5 Power Precision ...................................................................................................................................... 6

5.2 BTS Parameter Settings ................................................................................................................................... 7

5.2.1 Saving Current Settings .......................................................................................................................... 7

5.2.2 Setting BTS Parameters .......................................................................................................................... 7

6 Test Procedure ............................................................................................................................. 11

6.1 Testing the BCCH TRX Power ...................................................................................................................... 11

6.2 Testing the Non-BCCH Power ....................................................................................................................... 13

6.3 Testing the TOC ............................................................................................................................................. 17

6.4 Ending the Test ............................................................................................................................................... 17

7 Precautions and Procedures for Setting the NRT Power Meter ......................................... 22

7.1 Introduction to the NRT Power Meter ............................................................................................................ 22

7.2 Method for Using the NRT Power Meter ....................................................................................................... 23

7.2.1 Powering on the NRT Power Meter ...................................................................................................... 23

7.2.2 Setting the Test Mode............................................................................................................................ 23

7.2.3 Recalibrating the Power Meter.............................................................................................................. 26

7.3 Precautions ..................................................................................................................................................... 27

GBTS Product TOC Test Guide ‎1 Test Purpose



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1 Test Purpose

This document provides a guidance for testing the transmit power at the top of the BTS

cabinet (TOC) of GBTS products, such as BTS3012, BTS3900, and DBS3900.

GBTS Product TOC Test Guide ‎2 Test Method



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2 Test Method

The NRT power meter is used together with the LMT to test the power of TRX modules. The

methods for testing various types of TRX modules are the same.

GBTS Product TOC Test Guide ‎3 Test Networking



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3 Test Networking

Figure 3-1 Networking for the test

performed using the NRT power

meter

NOTE

The measurement points for the NRT power meter are located between the test port (antenna port or

TRX port) and the RF load.

GBTS Product TOC Test Guide ‎4 Test Material



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4 Test Material

No. Name Description Quantity

1 NRT power meter The NRT power meter is manufactured by Rohde & Schwarz

(R&S).

1

2 Load High-power load 1

3 Cable RF cable At least 3

4 Conversion

adapter

The model and quantity of required conversion adapters

(such as N, SMA, and DIN) are determined based on the test

port.

GBTS Product TOC Test Guide ‎5 BTS Configuration and Precautions



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5 BTS Configuration and Precautions

5.1 Introduction

5.1.1 TRX Binding Relationship

When testing the power, determine the number of test TRXs configured on the TRX board

pass based on the TRX index and TRX board pass number. To determine the TRX binding

relationship, run the LST TRXBIND2PHYBRD command or search for the following

command in the MML configuration:

ADD TRXBIND2PHYBRD: TRXID=0, IDTYPE=BYID, BTSID=1, TRXTP=MRRU,

TRXPN=0, RXUIDTYPE=SRNSN, CN=0, SRN=4, SN=0, ANTPASSNO=A;

5.1.2 Power of Various Channels

The downlink power of different channels varies depending on their types either when they

are idle or occupied. When testing the power of a TRX, ensure that all channels for the TRX

transmit signals at full power.

BCCH: The downlink BCCH always transmits signals at full power.

PDTCH: When the PS Downlink Power Control and PS DTX features are not enabled,

the downlink PDTCH transmits signals at full power even in the idle state. Due to

difference between the modulation modes of PS and CS services, the downlink power of

the PDTCH is slightly lower than that of the TCH.




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TCH: When power control is enabled, the occupied TCH transmits signals based on the

controlled power, whose power level is generally lower than the configured static power

level. An idle TCH for a non-BCCH TRX does not transmit signals.

NOTE If downlink DTX is enabled when no voice frame is transmitted during a call, ensure that the BTS does

not transmit signals.

To query the channel type, run the LST GTRXCHAN command or search for the following

command in the MML configuration:

SET GTRXCHAN: TRXID=0, CHNO=0, CHTYPE=MBCCH;

5.1.3 Dummy Burst Test

The dummy bust test function enables a TRX to transmit signals at full power on an idle

downlink channel within the specified detection duration.

NOTE Enabling this function for a locked TRX may lead to unstable downlink power. Therefore, do not enable

this function for a locked TRX during a power test.

5.1.4 Impacts of OM Operations on a Power Test

A faulty or locked TRX or channel does not transmit signals. During a power test, ensure that

all channels for test TRXs function properly.

When a TRX or channel is shut down, the BSS reserves the ongoing services and prevents

new services from accessing the network, but it does not shut down the power.

NOTE

Locking the BCCH TRX or TRX that enabling baseband frequency will lead to TRX aiding, which

affects the test result. Therefore, disable TRX aiding before performing a power test. For details, see the

BTS parameter settings.

5.1.5 Power Precision

The power of various types of boards fluctuates within the standard power range. The specific

power range of each board subjects to the power template in the sales guide for each product

(error tolerance). The fluctuation ranges of some typical boards are as follows:

DRRU: +/– 0.8 dB

DRFU: +/– 0.8 dB (PBT mode: +/- 1.5 dB)

MRRU V1/V2: +/– 0.8 dB




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MRFU V1/V2: +/– 0.8 dB

The conversion between W and dBm is in a non-linear manner. Assuming a constant error

tolerance dB value, the W value varies depending on power types.

dBm = 10 x logW x 1000

5.2 BTS Parameter Settings

5.2.1 Saving Current Settings

During a TOC test, parameter settings need to be modified. Therefore, you are advised to save

the BSC MML scripts before the test. To save the BSC MML scripts, run the command shown

in the following figure. The command output contains the file saving path.

5.2.2 Setting BTS Parameters

1. Disable downlink power control.

To disable downlink power control in a cell, run the following command:

SET GCELLBASICPARA: IDTYPE=BYID, CELLID=xx, DNPCEN=NO;




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NOTE When downlink power control is enabled, the BSC adjusts the BTS transmit power based on the call

quality and signal level. If an MS accesses the network, the TOC fluctuates.

2. Disable DTX.

To disable DTX in a cell, run the following command:

SET GCELLBASICPARA: IDTYPE=BYID, CELLID=xx, FRDLDTX=NO,

HRDLDTX=NO, FRULDTX=Shall_NOT_Use, HRULDTX=Shall_NOT_Use;

NOTE

The DTX function enables a TRX to stop transmitting signals when there is no voice signal during a call.

Enabling the DTX function affects the TOC test result.

3. Disable baseband FH.

To disable baseband FH in a cell, run the following command: (Ignore this step if

baseband FH is not involved.)




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SET GCELLHOPQUICKSETUP: IDTYPE=BYID, CELLID=xx, FHMODE=NO_FH;

NOTE

If a TRX enabled with baseband FH hop to frequency not its own, the TRX does not transmit signals on

the downlink. This affects the test result.

4. Disable the TRX aiding function.

To disable the TRX aiding function in a cell, run the following command:

SET GCELLCCACCESS: IDTYPE=BYID, CELLID=xx,

TRXAIDSWITCH=TRXAid_NotAllow;

NOTE TRX aiding is classified into BCCH TRX aiding and baseband FH TRX aiding. When the BCCH TRX

is locked, BCCH TRX aiding takes effect. That is, services carried on the locked BCCH TRX in a cell

are handed over to a functional non-BCCH TRX. When a non-BCCH TRX participating in baseband FH

is locked, baseband FH TRX aiding takes effect. That is, the system automatically changes the cell FH

mode to none FH. To eliminate impacts on the test results, TRX aiding is temporarily disabled.

5. Change PDTCH to TCH.

To change PDTCH to TCH, run the following command:

SET GTRXCHAN: TRXID=xx, CHNO=yy, CHTYPE=TCHFR;




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GBTS Product TOC Test Guide ‎6 Test Procedure



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6 Test Procedure

6.1 Testing the BCCH TRX Power

1. Before testing the power, preheat the test modules and instruments for about 30 minutes.

This helps to improve the accuracy of the test result.

2. Set the NRT power meter by referring to section ‎7.2 "Method for Using the NRT Power

Meter."

3. Shut down the cell served by the test TRX, reserve the ongoing traffic, and prevent new

services from accessing the network.




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4. Monitor the channel status and ensure that all channels are idle.

5. Set BTS parameters by referring to section ‎5.2 "BTS Parameter Settings."

6. Determine the antenna path of the board where the test TRX is located by referring to

section ‎5.1.1 "TRX Binding Relationship" and lock the cell served by the test TRX. To

avoid VSWR alarms, ensure that no other TRX is transmitting power when test.

7. Install TRX modules and test devices by referring to ‎Figure 3-1. After the test devices

have been installed correctly, unlock the cell served by the test TRX.

8. Retain the test BCCH TRX in the Unlock status and then determine the number of the

antenna path where the test BCCH TRX is configured. During the test, ensure that

non-BCCH TRXs on the antenna path are in the Lock status.




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9. When the value of the power meter becomes stable, read and record the value, which is

the TOC power of the test BCCH TRX.

6.2 Testing the Non-BCCH Power

1. Before testing the power, preheat the test modules and instruments for about 30 minutes.

This helps to improve the accuracy of the test result.

2. Set the NRT power meter by referring to section ‎7.2 "Method for Using the NRT Power

Meter."

3. Shut down the cell served by the test TRX, reserve the ongoing services, and prevent

new services from accessing the network.




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4. Monitor the channel status and ensure that all channels are idle.

5. Set BTS parameters by referring to section ‎5.2 "BTS Parameter Settings."

6. Determine the antenna path of the board where the test TRX is located by referring to

section ‎5.1.1 "TRX Binding Relationship" and lock the cell served by the test TRX. To

avoid VSWR alarms, ensure that no other TRX is transmitting power when test.




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7. Install TRX modules and test devices by referring to ‎Figure 3-1. After the test devices

have been installed correctly, unlock the cell served by the test TRX.

8. Retain the test non-BCCH TRX in the Unlock status and then determine the number of

the antenna path where the test non-BCCH TRX is configured. During the test, ensure

that other TRXs on the antenna path are in the Lock status. If the antenna path for the

test non-BCCH TRX is the same as that for the BCCH TRX, retain the BCCH TRX in

the Lock status and the non-BCCH TRX in the Unlock status.




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9. Enable the dummy burst test function for the test non-BCCH TRX using either of the

following methods:

MML command:

STR TRXBURSTTST: OBJECTTYPE=BYTRX, TRXID=xx, DURATH=1;

NOTE: The test duration in the preceding command is 1 hour. Finish the test before the

dummy burst test ends.

GUI:




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10. After the dummy burst test, wait for about 5 minutes until the power meter becomes

stable. Then, read and record the value, which is the TOC power of the test non-BCCH

TRX.

11. After the test, stop the dummy burst test using either of the following methods:

MML command:

STP TRXBURSTTST: OBJECTTYPE=BYTRX, TRXID=xx;

GUI:

6.3 Testing the TOC

The method for testing the TOC is the same as that for testing a single TRX. Enable the

dummy burst test for all TRXs in the test cell and read and record the power meter value.

6.4 Ending the Test

1. Lock all TRXs at the measurement points and reconnect the antenna.




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Check the saved MML configurations and operation records and restore the BTS parameters

to the initial settings.

(1). Restore the downlink power control and DTX settings.

Search for the following command in the saved MML configurations based on the cell index,

and then copy and execute the command.

SET GCELLBASICPARA: IDTYPE=BYID, CELLID=xx...

(2). Restore baseband FH.

If the cell FH mode has been changed during the test, restore the FH mode after the test.

Otherwise, ignore this step.

(a) Deactivate the current cell.




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(b) Search for the following commands in the saved MML configurations based on the cell

index and TRX index, and then copy and execute the commands.

SET‎GTRXHOP:TRXID=yy…

SET‎GTRXCHANHOP:TRXID=yy…

ADD‎GCELLMAGRP:‎IDTYPE=BYID,‎CELLID=xx…

SET‎GCELLHOPTP:CELLID=xx,‎IDTYPE=BYID…

SET GCELLMAIOPLAN:‎IDTYPE=BYID,‎CELLID=xx…

If there are multiple commands, run the MML commands in batches to restore the

configurations.

(c) Activate the current cell.




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(3). Restore TRX aiding.

Search for the following command in the saved MML configurations based on the cell index,

and then copy and execute the command.

SET‎GCELLCCACCESS:‎IDTYPE=BYID,‎CELLID=xx…

(4). Restore the PDTCH configuration.

Restore the channel type to PDTCH by running the following command:

SET GTRXCHAN: TRXID=xx, CHNO=yy, CHTYPE=PDTCH;

2. Restore the admin status of all TRXs to Unlock.




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‎7 Precautions and Procedures for Setting the NRT Power

Meter



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7 Precautions and Procedures for Setting the NRT Power Meter

7.1 Introduction to the NRT Power Meter

The NRT power meter is a transmission power meter manufactured by R&S. It consists of a

main frame and several power probes. The power probes are connected to the Sensor ports on

the main frame, as shown in ‎Figure 7-1

Figure 7-1 Power ports (left) and

main frame (right) of the NRT

power meter



Meter



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7.2 Method for Using the NRT Power Meter

7.2.1 Powering on the NRT Power Meter

1. Connect the power cable to on the backplane and supply the 220 V power.

2. Press , as shown in ‎Figure 7-2. To improve the accuracy of the test result,

preheat the NRT power meter for about 30 minutes before the test.

Figure 7-2 Pressing the ON/STBY

key

7.2.2 Setting the Test Mode

1. Set ENV KEY to AV.BRST.

Step 1 Step 1 On the MENU panel of the main frame, press to enter the parameter

setting interface, as shown in ‎Figure 7-3 Press or to set ENV KEY to

AV.BRST, and then press .

Figure 7-3 Setting ENV KEY to

AV.BRST

ON/STBY



Meter



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Step 2 Switch to the next interface, as shown in ‎Figure 7-4 Press or to set AV.BRST

to AUTO, and then press .

Figure 7-4 Setting AV.BRST to

AUTO

Step 3 Switch to the next interface, as shown in ‎Figure 7-5. Set VID.BW to FULL, and then press

.

Figure 7-5 Setting VID.BW to

FULL

----End

2. Set power parameters.

Step 1 Step 1 Press and to enter the POWER interface, as shown in ‎Figure 7-6

Press or to set POWER to FWD, and then press .

Figure 7-6 Setting POWER to

FWD



Meter



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Step 2 Press to select the power mode, as shown in ‎Figure 7-7.

Figure 7-7 Selecting the power

mode (timeslot power)

Step 3 Press to select the required unit (dBm or W), as shown in ‎Figure 7-8

Figure 7-8 Selecting the power unit

Step 4 Step 4 Press to select the power range. Press the right key to increase the

power range and the left key to decrease the power range. Set the power range to 50 to 60

dBm, as shown in ‎Figure 7-9

Figure 7-9 Selecting the power

range

----End



Meter



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3. Set frequency parameters.

Step 1 Press to enter the FREQ interface, as shown in ‎Figure 7-10 Set FREQ to USER, and

then press .

Figure 7-10 FREQ interface

Step 2 After entering the USER interface shown in ‎Figure 7-11, press or to select the

location to be modified, and press or to change the value of the specified

location. To increase the value, press . To decrease the value, press .

Figure 7-11 Frequency setting

method

----End

7.2.3 Recalibrating the Power Meter

To improve the test accuracy, recalibrate the power after setting the aforementioned

parameters.

Step 1 Shut down the transmit power and ensure that probes 1 and 2 of the power meter are fully

open-circuited or configured with mapping load.

Step 2 Press and to enter the ZERO interface, as shown in ‎Figure 7-12. Select EXEC,

and then press .



Meter



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Figure 7-12 ZERO interface

Step 3 When ZEROING shown in ‎Figure 7-13 is displayed, recalibrating is in progress. Wait until

recalibrating is complete.

Figure 7-13 ZEROING interface

----End

7.3 Precautions

1. The power capacity of the NRT power meter is 300 W. To prevent the probes from

burnout, the NRT can be used to test only power less than 300 W.

NOTE

The power capacity of the NRT power meter is determined by the port type. You are advised to use the

NRT-Z44 probe. If you need to use other types of probes, contact Huawei technical support.

2. The RF load over probe 2 must meet the following requirements:

The power capacity must be sufficient. Otherwise, the load may be burned.

The VSWR must be less than 1.5. Otherwise, the VSWR test precision decreases.

3. The probes for the NRT power meter must be connected in the sequence shown in ‎Figure

7-14. Otherwise, probes may be burned.



Meter



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Figure 7-14 Connection sequence

for power meter probes

4. The power meter must be recalibrated before the test. Otherwise, the test results are

inaccurate.

5. Set the power meter by strictly following the requirements stated in the related guidance.

Otherwise, the test results may be inaccurate. For items that are not specified in the

guidance, set them to defaults values.

6. For GSM signals, you are advised to set the test mode of the NRT power meter to AVG

BRST, because the timeslot power tested in this mode is more accurate. The timeslot

power tested in AVG mode is 0.1 to 0.2 dB less than the actual timeslot power.

7. If a cable is used to connect the input port of the power meter to the test port, set the

compensation value to compensate for cable loss. ‎Figure 7-15 shows the compensation

method.

Figure 7-15 Location of cables

requiring compensation

Step 1 Press and to enter the MERS.POS interface, as shown in ‎Figure 7-16. Set

MEAS.POS to LOAD SOURCE, and then press .

Figure 7-16 MERS.POS interface



Meter



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Step 2 Set the OFFSET to the value of cable loss, and then press or to select the

location to be modified, and press or to change the value of the specified

location. To increase the value, press . To decrease the value, press .

Figure 7-17 OFFSET interface

----End

8. The NET power meter can test only one TRX each time without distinguishing

frequencies. During the test, other TRXs must be locked.

9. Some NRT power meters do not support setting OFFSET. In this case, compensate for

cable loss by adding an appropriate value to the test value. The following figure shows

the mapping between cable loss, cable length, and frequencies.

For a one-meter long cable, the compensation value for the cable loss is about 0.1 dB on the

900 MHz frequency band and about 0.15 dB on the 1800 MHz frequency band.

NOTE: Cable loss listed in the preceding table refers to the cable loss of the jumper between

the cabinet top and the antenna. If other cables are used, the cable loss increases.

Documents

GBTS Product TOC Test Guide