E2-E3: CONSUMER MOBILITY. CHAPTER-3 MAINTENANCE ISSUES OF BTS (Date of Creation: )

Transcription

1 E2-E3: CONSUMER MOBILITY CHAPTER-3 MAINTENANCE ISSUES OF BTS (Date of Creation: ) Page: 1

2 Maintenance Issues Of BTS Maintenance Issues of BTS There are two methods of BTS Maintenance 1. Preventive maintenance 2. Corrective maintenance. 1. Preventive Maintenance Preventive maintenance of BTS is carried out to avoid any failure and also to meet the Quality objectives. Preventive maintenance shall be done once in six months for all types of BTS. Observation and measured values of preventive maintenance are recorded in the inspection book. Procedure of preventive maintenance of BTS Before performing preventive maintenance activities of a BTS, all other related elements in the network linked with BTSs, are also to be checked. All sites ground based as well as roof top and also pole structures are to be checked for the following and activities/values to be recorded in the logbook. Important Points:- Performance of sensor and lamp is to be checked. Lightning spike earth, Tower earths, DG & Equipment earth to be checked (Must be less than 1 ohm for each earth ) Check the earth continuity from the earth pit to the EGB Check VSWR for each sector, it must be less then 1.3 Antennae & Tower:- To be verified as and when any faults/defects (like high VSWR) reported or once in a year whichever is earlier. Visual check of bolts/nuts and sample check of their tightness, Greasing on foundation bolts to be done. Check the Antenna connectors and their tightness. Check for tightness of antenna fixtures, u clamps etc.. Check for ingress of water (condition of weather proofing in waveguide) etc Check the orientation of antenna of each sector and compare with the old records. Check for the down tilt of antennae which also may be compared with old records. Page: 2

3 2. Corrective Maintenance of BTS Whenever any fault is reported from or during periodic visits/inspections, the corrective maintenance is done for the BTS site in accordance with alarm escalation matrix.the effectiveness of preventive maintenance and corrective maintenance is verified with the performance reports of the site from OMCR.After any major modification in the BTS site like change in antenna settings,site configuration, power etc., drive test and optimization of the site is done in accordance with the Operating Procedure. Changes made during preventive/corrective maintenance are entered in the logbook 3. Problems In The Network Low network availability Low network stability Large Number of BTS remains down which causes Coverage problem Hand over problem Large amount of radio capacity unavailable Which is due to Power Failure and Low battery back up Non functioning of DG at the time of Power failure Transmission media failure Delay in restoration RF Issues Overloaded BTS requires load balancing with adjacent BTS by tilting/lowering down/raising up BTS antennas. Riggers are not available for getting done above work. Radio Capacity loading in DHQ,s & big Towns is around 90% or more but in rural area many of the BTS,s are underloaded because of not having required coverage. Such BTS needs immediate action to make them Riggers are not available for getting done above work Drive test shows quantitatively the interference problem which needs to be corrected by tilting/lowering down/raising up BTS antennas. Riggers are not available for getting done above work. Any fault/damage in Feeder cable(causes VSWR fault), IF cable (mini link) requires change of these. Such faults are regular phenomenon in the network. Neither this material is in the scope of vendor nor available with CMTS O&M. Page: 3

4 In Multi BTS area whenever BTS goes out of order, handover starts failing due to non availability of neighbor cell. Round the clock working of all BTS shall be ensured. BTS grid shall be maintained while planning new BTS,s in multi BTS cluster. Improperly placed BTS causes RF problems. Page: 4

5 Chapter 3: Maintenance Issues Of BTS Sample self study Objective Type Questions 1.There are two methods of BTS Maintenance is done by method. a)preventive maintenance b)corrective maintenance. c) Both a & b 2. In BTS maintenance Lightning spike earth, Tower earths, DG & Equipment earth must ohm. a) 5 b) 1 c) 2 d) 4 3. During BTS maintenance Check the VSWR for each sector, it must be less. a) 1.3 b)4 c) 3 d) 2 4. In BTS site the Network Problem is. a) Low network availability b) Low network stability c) Both a&b 5. BTS failure may be due a) Power Failure b) Transmission media failure c) either of a or b Page: 5