Mini Link Troubleshooting and Power Analysis pdf PDF

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Copyright © Copyright Task Force Managed Services EID Disclaimer No part of this document may be reproduced in any form without the written permission of the copyright owner. Content 1 Abstract ..........................................................................................2 1.1 Task Force...

Description

Copyright © Copyright Task Force Managed Services EID Disclaimer No part of this document may be reproduced in any form without the written permission of the copyright owner.

Content 1

Abstract ..........................................................................................2

1.1

Task Force Output ...........................................................................3

2

Guideline on Trouble Shooting of MINI-LINK Equipment..........4

2.1

Prerequisite......................................................................................5

2.2

Preparation ......................................................................................6

2.3

TOC .................................................................................................8

3

Guideline on Trouble Shooting of Power Related Problem ....27

3.1

Prerequisite....................................................................................28

3.2

Preparation ....................................................................................29

3.3

TOC ...............................................................................................31

4

Enclosure .....................................................................................58

4.1

Transmission AND RBS Data Report............................................59

4.2

Power Data Report ........................................................................63

PAGE 1

1 ABSTRACT After analysis of trouble ticket trend for over 6 months, Managed Services delivery team notices a pattern of recurring problem related to MINI-LINK and power related issue. In an effort to reduce the recurring problem, a task force focusing on the issues were set up, with a goal to find the root cause of the recurring problem. The type of MINI-LINK recurring problem that were focused on included: NPU hanging (stuck in boot process) for AMM 2p B RSL with measurement of -20dB Performance degrading on sites with antenna over 1.2m High temperature leading to MINILINK software hanging in TN R2 Power related problem investigation was focused circuit breaker (MCB) tripping due to: Unbalanced power consumption Insufficient commercial power capacity Low voltage from commercial power Phase failure As an outcome of the investigation, this document is produced as a guideline to help field maintenance technicians & engineers for troubleshooting similar problem Ericsson official documentation for MINI-LINK operational and maintenance guideline should always be the main reference for any operational activities. This document is to be used specific for the problem described above.

PAGE 2

1.1

Task Force Output DOWNTIME CONTRIBUTOR 8,835 in December (1044 less compared to November) 920 less power related problem; due to battery replacement, faster response on RST alarm 144 less problem for other issue, mainly transmission, MCB trip cases; due to task force activity that focused on recurring transmission problem and MCB trip cases TT Type: December 2009

Lease Line, 22, 0% Access Issue, 34, 0% RNC, 1, 0% BTS, 210, 2% Transmission, 157, 2%

Pow er Outage, 7982, 91%

CME, 308, 4% P o wer Outage

CM E

3rd P arty

P ro ject

B SC

Others

Transmissio n

B TS

NODE-B

A ccess Issue

RNC

Lease Line

Downtime contributor 1.600% 1.400% 1.200% 1.086%

1.000%

0.704% 0.800%

0.442%

0.590%

0.600% 0.395%

0.791% 0.557%

0.426%

0.654% 0.634%

0.473% 0.572%

0.400%

0.589% 0.575% 0.531% 0.504% 0.440% 0.372% 0.200% 0.367% 0.290% 0.292% 0.228% 0.213% 0.150% 0.000% Wk Wk Wk Wk Wk Wk Wk Wk Wk Wk Wk Wk 1 43 44 45 46 47 48 49 50 51 52 53 % - EID

% - External

PAGE 3

2 Guideline on Trouble shooting of MINI-LINK Equipment

PAGE 4

2.1

PREREQUISITES This chapter describes the hardware tools & software programs that are needed when trouble shooting shall be done for MINI-LINK equipments. Engineer always needed to bring the right tools for working with troubleshooting on sites. Please do not forget to prepare the required sites permit and necessary coordination to make sure our activities on sites will be done smoothly. Tools that are needed: a. Notebook and accessories cables (USB, Ethernet, and RS232). b. MSS (MINI-LINK Service Software) installed in the notebook. c. Correct SW version for all equipment if upgrades are necessary (include the latest software baseline). d. Basic Tools: digital Volt-meter, LED, screw-driver sets, DDF punch tools, wrist-stripe, etc e. HSE Tools f.

If required, always bring BER meter for checking E1 / STM-1 performance.

g. If needed, always bring HW spares (Ex MMU, TRU, NPU, RAU and dummy) that might need to be replaced. h. If needed, always bring RAU connectors, electrical insulating tape, butyl sealing compound for water protect the RAU connector/cable. Access Permit & Coordination procedures that are needed; a.

Working permit and site key access.

b.

Customer approval for equipment down time if needed

c.

Always Coordinate with Customer NOC / OMC

d.

Approvals from NOC before and after enter the site.

PAGE 5

PREPARATION Considering most of trouble-shootings will be done on existing (with live traffic) sites, we should follow our Network Interruption process. Information on the request form (Day “H”) 1.Site name 2.SOW activity on site 3.Person in charge From EID organzation 4.Site access (related with the request for Key arrangement and Supervisor from Customer) 5. Time frame of the activity

Prepare Request Form to Enter Customer Site Revise data on the form

2.2

The Form send to Customer for approval

No

1.Customer give approval by signing the request form (Day H+1)

All data approved by Customer Yes

Engineer Received Key and information on PIC from Customer Spv

Engineer arrived on site

Before enter the site Call OMC 1.Identify yourself to OMC and Gave information regarding the task 2. Ask if Site has alarm or not 3.Show / give the letter of assignement ot the spv of the sites if one exist .Such as IBS (in building solution )site

Call /report to OMC

Anything Unusual on Site

1. Check Sorrounding of the site for anything unusual Such as Grounding missing;Fence broken etc. 2..Check Inside the shelter , Save alarm or status of the RBS related to Engineer’s work 3.Take Foto for unusual conditional

Engineer doing the Activity

Engineer completing the activity+ Clean Up site

Call OMC before left the sites

1. Make sure that the site is clean 2. Make sure the RBS status has the sama or less alarm status compare before engineer enter the shelter

Give notification to OMC that you already completed the activity on related site Confirmation on the status site from OMC

Return Sheter Key to Custome by filling the report

end

Picture 1

Network Interruption process

PAGE 6

General key-points before starting our trouble-shooting main activities:

a. Inform Customer NOC team about our activity on site, especially if traffic interruption will be done, before and after our activity.

b. Check surrounding condition if any Unusual Condition found, such as; Grounding missing, broken KWH, abnormal indoor temperature, etc. If needed, take capture / picture as evidences and inform to NOC Team.

c. Check Physical condition of ML equipments especially for LED Status and Input DC voltage • If we found RED Light or strange Status, check details by LCT for verification, and take/save Capture & Logs. For more information, see LED Descriptions MINI-LINK TN Operating Instructions, Reference [4] • Measure the Input Vdc using a Digital Voltmeter, and compare it with the specification

Never Turn-Off / Reset the ML equipments before verifying and taking required information.

PAGE 7

2.3

Table of Content

1

Troubleshooting Procedure ...................................................... 9

1.1

Received Alarm / Fault Description .............................................. 9

1.2

Troubleshooting MLTN............................................................... 10

1.2.1

SW troubleshooting MLTN ......................................................... 10

1.2.2

Data Collection MLTN ................................................................ 11

1.3

Troubleshooting MLHC .............................................................. 11

1.3.1

SW troubleshooting MLHC on site ............................................. 11

1.3.2

Data Collection MLHC................................................................ 12

1.4

Hardware Installation Check ...................................................... 12

2

Example problem found in Transmission.............................. 13

2.1

Hardware Faulty ......................................................................... 13

2.1.1

RAU with RSL – 20 dBm ............................................................ 13

2.1.2

AMM 2p B faulty ......................................................................... 14

2.2

Low RSL..................................................................................... 15

2.3

Switching 1+1 HS failed (MMU2 D)............................................ 18

2.4

HCC/RCC Alarm ........................................................................ 20

3

Problem analysis & Escalation Process ................................ 23

4

Replacement Faulty Module.................................................... 24

5

Closing Preparation ................................................................. 25

6

Reporting .................................................................................. 25

7

Reference .................................................................................. 26

PAGE 8

1.

TROUBLESHOOTING PROCEDURE Please follow our general Technical Trouble-shooting process:

Picture 2

1.1

General trouble-shooting process

Received Alarm / Fault Description The receiver alarm / fault description should include details about the following: a.

Exact date and time of the problem. The time shall be given in relation with the time setting in the affected NEs.

b.

Effect of the problem. Explain the fault events as they occurred, step by step. Specify slot positions when applicable.

c.

Events that might have lead to the fault.

d.

Frequency of the fault.

e.

Software Baseline (SBL) running on the NE when the fault occurred.

PAGE 9

1.2

Troubleshooting of MLTN

1.2.1

SW Troubleshooting MLTN on site Please follow below procedure of trouble-shooting MLTN: a.

Connect to the MLTN (using Ethernet or USB cable)

b.

Check the event / alarms / fault to evaluate what the problem is See more details information in documents of:

• Fault Management Operations MINI-LINK TN ETSI, Reference [6]

• Alarm Descriptions MINI-LINK TN ETSI Description, Reference [7] • Event Descriptions MINI-LINK TN ETSI Description, Reference [8]

c.

Verifying Radio Link Configuration Parameters Verify that all hop setup parameters are set and correspond to the value in SID / PQR, such as: RSL (Received Signal Level), Tx power, Switching mode, Frequency setting, etc.

d.

Checking for RF Interference If the Radio Link reports unexpectedly bad BER performance but RF input level is normal, the receiver might be interfered by external RF sources. Check RF interference using Far-end Tx-off procedure.

e.

Use a loop on the unit that having problem to trace the fault (i.e.: RF Loop, IF Loop, etc).

f.

Use built-in BERT (Bit Error Ratio Tester) or external BER meter to verify or trace the fault.

g.

Restarting the NE (Network Element) In some cases, if required, we can do a Warm or Cold Restart of the NE.

• A cold restart will disturb the traffic. • Always collect Logs before restarting the NE since the alarm and event logs, as well as power cycling information, are deleted at both cold and warm restarts and potentially valuable information is lost. h.

Take capture of specific problems.

i.

Check and (if required) perform SW upgrade if it’s an older SW-baseline version.

PAGE 10

The SW version should be checked with O&M to synchronize that the MINI-LINK has the same SW baseline in all MLTN. Please perform a software upgrade to the new software baseline according to the MINI-LINK TN ETSI Operating Instruction, Reference [2] or MINILINK Craft User Interface Descriptions, Reference [3], chapter ”Software Upgrade”. For details about recommended upgrade paths of MLTN, please also see the Compatibility Information and Release Note documents.

1.2.2

Data Collection MLTN Take following data from MLTN terminals for any further technical analysis or escalation:

a.

Error log file and Event log / history Always collect alarm logs and event log before any warm/cold restart or power cycling.

b.

Alarm list (needs to be done before power reset)

c.

Get the configuration file and saved report if you don’t have the latest file

d.

Collect PM (Performance Management) data if PDH/SDH MMUs is used (Near & Far end)

1.3

Troubleshooting of MLHC

1.3.1

SW Troubleshooting MLHC on site Please follow below procedure of trouble-shooting MLHC: a.

Connect to the MLHC (using Ethernet or Serial OM cable)

b.

Take Capture of existing parameters needed and Save Configuration for backup purposes

c.

Check the alarms to evaluate what the problem is.

d.

Always upload the Alarm logs of MLHC

e.

Verifying Radio Link Configuration Parameters refer to SID / PQR

f.

Checking for RF Interference

g.

Use loops to trace were the problem is (example : RF Loop, IF Loop, SPI Loop)

h.

If necessary, use external BER meter to verify or trace the fault.

i.

Always take capture of specific problems. PAGE 11

j.

Make a save before any power cycling.

Note: If you have not save before power cycle and you have made any changes the TRU will go back to the latest saved configuration. k.

Perform SW upgrade if it’s an older SW version. This should be checked from the O&M what version that shall be used.

1.3.2 Data Collection MLHC Take following data from MLHC terminals for any further technical analysis and escalation:

a.

Alarm logs from (Near-end and Far-end). Needs to be collected before power reset.

b.

Performance log (monitoring data) from Near-end and Far-end. If performance data is not available, follow the performance setup in as document of Settings for performance measurements in Mini-Link High Capacity, Reference [13]

1.4

c.

Inventory data (Near-end and Far-end)

d.

Configuration file

Hardware Installation Check Aside checking the software status, in some conditions we need to check physical installation also: a.

FAN unit correctly installed on MLTN / MLHC.

b.

Dummy fronts installed (MLTN).

c.

Grounding completely & properly installed according to the installation manuals

d.

Traffic and DC Cabling/Connectors properly installed. See more details in document of Installing Indoor Equipment MINI-LINK TN ETSI Installation Instructions, Reference [1].

e.

Radio cable and the connectors properly installed. (See more details in document of Radio Cable Check [13].

f.

All connectors tightened (DC/traffic/radio)

g.

Check power distribution (battery, DC power level and MCB Ampere). PAGE 12

2.

h.

Modem units correctly inserted and tightened

i.

If the problem is still intermittent, check interfaces on front and the backplanes for broken or damage pins

Example Problem found in Transmission 2.1 Hardware Faulty 2.2 Low RSL 2.3 Switching 1+1 HS failed (MMU2 D) 2.4 HCC/RCC Alarm

2.1

Hardware Faulty

2.1.1 RAU with RSL -20 dBm In the Radio Link Alarm, we found the RSL of the RAU is – 20 dBm. In 1+1 HS configuration, sometimes the switch can not work caused by this problem. There is a known problem with a component handling the attenuation on the RAU. The following steps must follow to solve the problem; 1.

Prepare RAU with same product code.

2.

Unplug jumper cable on MMU.

3.

Replacement RAU with the new one.

4.

Plug jumper Cable onto MMU.

5.

Reset Performance in Near End and Far End

6.

Send the RAU to Ware House with BLUE TAG FORM.

Note: Write in Remark Column; RAU faulty with RSL – 20 dBm.

PAGE 13

2.1.2 AMM 2p B Faulty AMM 2p B faulty with problem NPU stuck in Boot Process. There is a known problem with a bad soldering of the component in the backplane. The Fault LED in NPU was ON. The following steps must follow to solve this problem; 1.

Prepare new AMM 2p B

2.

Turn off DC Source. Unplug DC cable from AMM 2p B (faulty).

3.

Unplug some modules from AMM 2p B: NPU3, MMU and FAU4.

4.

Uninstall AMM 2p B (faulty).

5.

Install new AMM 2p B.

6.

Plug in some modules into new AMM 2p B: NPU3, MMU and FAU4.

7.

Plug in DC Cable to AMM 2p B.

8.

Turn ON DC Source then pressing the BR button of NPU (2-3 seconds after Turn ON DC source).

9.

The LED BR in the NPU will flash. It means, the NPU in Installation mode status.

10.

Log in to ML TN with your laptop.

11. Activate the configuration from RMM card. 12. If AMM 2p B does not have RMM, You have to activate configuration with LOAD CONFIGURATION FILE from your laptop. 13. Otherwis...