HUAWEI TECHNOLOGIES CO., LTD. All rights reserved www.huawei.com Internal OME200301 GSM BTS Trouble Shooting ISSUE 3.0 HUAWEI TECHNOLOGIES CO., LTD. Page 2 All rights reserved References  M900/M1800 Base Station Subsystem Troubleshooting Manual  M900/M1800 Base Station Controller Technical Manual HUAWEI TECHNOLOGIES CO., LTD. Page 3 All rights reserved Upon completion of this course, you will be able to:  Know how to find the fault in BTS  Know the common fault types  Grasp BTS fault disposal method  Know how to prevent the fault HUAWEI TECHNOLOGIES CO., LTD. Page 4 All rights reserved Chapter 1 General Introduction Chapter 1 General Introduction Chapter 2 Typical Cases Chapter 2 Typical Cases Chapter 3 BTS Fault Prevention Chapter 3 BTS Fault Prevention HUAWEI TECHNOLOGIES CO., LTD. Page 5 All rights reserved Chapter 1 General Introduction Chapter 1 General Introduction Section 1 The Way To Locate Fault Section 1 The Way To Locate Fault Section 2 Basic Disposal Method Section 2 Basic Disposal Method HUAWEI TECHNOLOGIES CO., LTD. Page 6 All rights reserved The ways to locate faults  Alarm  Alarm console  Alarm box  OMC Shell  Traffic statistics  Drive test  Routine inspection  Customer complain HUAWEI TECHNOLOGIES CO., LTD. Page 7 All rights reserved Locating fault equipment  If BSC has fault, usually it will affect some Sites or all of Sites  If BTS has fault, usually it just affect itself and the handover success rate of adjacent cells  During implementation or expansion, we can “Interchange ” BTS and judge whether the fault is because of BSC or BTS  During maintenance, BSC faults don’t just affect one BTS HUAWEI TECHNOLOGIES CO., LTD. Page 8 All rights reserved Common fault types  BTS fault  Antenna & Feeder  Transmission  Hardware connection fault  Hardware fault HUAWEI TECHNOLOGIES CO., LTD. Page 9 All rights reserved Chapter 1 General Introduction Chapter 1 General Introduction Section 1 The Way To Locate Fault Section 1 The Way To Locate Fault Section 2 Basic Disposal Method Section 2 Basic Disposal Method HUAWEI TECHNOLOGIES CO., LTD. Page 10 All rights reserved Basic disposal method  Analyzing the Alarm Information  Alarm information come from the BSS alarm system, indicated usually through sound, light, LED, and screen output, etc  It includes the detailed description of the abnormality, possible causes and restoration suggestions, involves the hardware, link, trunk and CPU loading ratio, etc It is a gist for the fault analysis and location  Analyzing the Indicator Status  Indicators can indicate the work status of circuit, link, optical path, node and active/standby mode besides that of the corresponding boards, usually used along with the alarm information generally  Analyzing Traffic Statistics Result  It is the most useful method for locating RNO fault. [...]... self-loop the E1 at the top of BTS cabinet and found the indicator of the E1 cable was OFF It means BTS is OK  Step2: self-loop the E1 on the DDF and found the indicator of the E1 cable was OFF It means the E1 from BTS to DDF is OK  Step3: self-loop the BSC on the DDF and found the E1 indicator is OFF It means the E1 from BSC to DDF is OK  Step4: power the TMU off and then on, the trouble still existed ... fails to access the network, calls cannot be established, call drop, TRX idle for a long time Downlink signal weakened Poor conversion quality, BTS coverage shrink No uplink signal Calls cannot be established BTS sensitivity weakened Poor conversation quality, BTS coverage shrink Standing wave alarm Standing wave alarm occurs at CDU LNA alarm LNA alarm occurs at CDU TTA alarm TTA alarm occurs at CDU... lies in the cooperation between the transmission device and BSC (or BTS) HUAWEI TECHNOLOGIES CO., LTD All rights reserved Page 29 Transmission Fault 2: OML alarm frequently  Handling process  Generally the reason maybe that the E1 grounding is not good, it cause interference, or transmission device is faulty − Check the TMU in the BTS to check E1 grounding settings − Test the resistance of the E1... alarm frequently  Handling process − Check whether the system is in the single-point-grounded state If not, modify the system to the single-point-grounded state, then check whether the trouble is removed − If the trouble is still not removed after the above measures, it may be considered that the problem lies in the transmission device, E1 or E1 interface board Check the connection and perform loop... Chapter 1 General Introduction Chapter 2 Typical Cases Chapter 3 BTS Fault Prevention HUAWEI TECHNOLOGIES CO., LTD All rights reserved Page 13 Chapter 2 Typical Cases Section 1 Antenna & Feeder Fault Section 2 Transmission Fault Section 3 Hardware connection fault Section 4 Hardware fault HUAWEI TECHNOLOGIES CO., LTD All rights reserved Page 14 BTS feeder system structure Antenn a TX T R X RX CDU RXD arreste... the E1 indicator is OFF It means the E1 from BSC to DDF is OK  Step4: power the TMU off and then on, the trouble still existed  Step5: remove the E1 from the DDF, the trouble still existed  Step6: disconnect the E1 at the top of BTS cabinet, power off the rack and removed the TMU Test the resistance between the cabinet-top E1 connector case and the grounding cable of the rack and found they were... process  Step7: change the TMU DIP switch that corresponded to the grounding of the E1 cable to OFF (ungrounded), the trouble still existed  Step8: remove the E1 connector from the DDF and change the TMU DIP switch that corresponded to the grounding of the E1 cable to OFF (ungrounded) The trouble disappeared  Step9: for confirming the reason, replace the TMU (with the E1 cable ungrounded) Let the E1... the E1 connector from DDF, the trouble disappeared HUAWEI TECHNOLOGIES CO., LTD All rights reserved Page 34 Chapter 2 Typical Cases Section 1 Antenna & Feeder Fault Section 2 Transmission Fault Section 3 Hardware connection fault Section 4 Hardware fault HUAWEI TECHNOLOGIES CO., LTD All rights reserved Page 35 Typical case: VSWR alarm for cable broken  Description  On BTS maintenance console, one TRX... path − Step4: Check whether the connectors involved in the RF signal path are tightened HUAWEI TECHNOLOGIES CO., LTD All rights reserved Page 19 Common faults on uplink  Description  No uplink signal  BTS sensitivity weakened  Analysis  No uplink signal − Step1: Try another antenna feeder (CDU excluded) which has proven to be normal to substitute the one without uplink signal ▪ If the uplink signal... the cell may be affected This is the basic principle to obey when using this method to locate the problem HUAWEI TECHNOLOGIES CO., LTD All rights reserved Page 21 Common faults on uplink  Analysis  BTS sensitivity weakened − If TTA is configured, first check whether there is any TTA alarm ▪ If so, the TTA is working abnormally ▪ Otherwise, check the CDU antenna port feeding » If no feeding is detected, . TECHNOLOGIES CO., LTD. All rights reserved www.huawei.com Internal OME200301 GSM BTS Trouble Shooting ISSUE 3.0 HUAWEI TECHNOLOGIES CO., LTD. Page 2 All rights. can “Interchange ” BTS and judge whether the fault is because of BSC or BTS  During maintenance, BSC faults don’t just affect one BTS HUAWEI TECHNOLOGIES