Here I write about GSM RF Optimization Step by Step and how to find KPI degradation and its solution.
The RF network optimization process can be categorized by the following steps:
Problem analysis
- Analyzing performance retrieved from tool reports and statistics for the worst performing BSCs and/or Sites
- Viewing ARQ reports for BSC/Site performance trends
- Examining planning tool coverage predictions
- Analyzing previous drive test data
- Discussions with local engineers to prioritize problems
- Checking customer complaints reported to local engineer
Checks prior to action
- Cluster definitions by investigating BSC borders, main cities, freeways, major roads
- Investigating customer distribution, customer habits (voice/data usage)
- Running specific traces on network to categorize problems
- Checking trouble ticket history for previous problems
- Checking any fault reports to limit possible hardware problems prior to test
Drive testing
- Discussion of drive test goals and objectives
- Defining drive test routes
- Collecting log files
- Scanning frequency spectrum for possible interference sources
- Re–driving questionable data
Areas of Investigation
- Non–working sites/sectors or TRXs
- Improper function of radio network features like frequency hopping, antenna hopping, etc.
- Limited data throughput and performance (GPRS/EGPRS)
- Overshooting sites – coverage overlaps
- Coverage holes
- C/I, C/A analysis
- High interference areas
- Dropped calls
- Capacity problems
- Other interference sources
- Inaccurate neighbor lists (including 1-way neighbor definitions)
- Handover ping-ponging
- Drops due to handovers
- Accessibility and retainability of the network
- Equipment performance
- Faulty Installations
After the test
- Data post processing
- Plotting RX level and quality information for overall picture of the driven area
- Initial discussions on drive test with local engineers
- Reporting urgent problems for immediate action
- Analyzing network feature performance after new implementations
- Transferring comments on parameter implementations after new changes
Recommendations
- Definition of missing neighbor relations
- Propose new sites or sector additions with before and after coverage plots
- Propose antenna azimuth changes
- Propose antenna tilt changes
- Propose antenna type changes
- Investigation of BTS Equipment/Filter change
- Re–tune of interfered frequencies
- Investigation of BSIC changes
- Adjustment of power settings
- Adjustment of handover margins (Power Budget, Level, Quality, Umbrella HOs)
- Adjustment of accessibility parameters (RX Lev Acc Min, etc.)
- Attenuation of Adds/Removals
- Propose MHA/TMA adds
Other optimization issues
- Verifying performance of new sites
- Verifying handovers
- Investigating GPRS performance
- Verifying sectorizations
- Collecting DTI scan files
- Verifying coverage
- Verifying propagation model by importing DTI scan files to Planet (any Analyzer)
- Periodic consistency checks
- Frequency planning check
- Analyzing cell access parameters
- Analyzing handover parameters
- Analyzing power control parameters
- Analyzing frequency hopping parameters (HSN, MAIO)
- Implementing/analyzing optional features
- Assisting local engineers with emergency cases
- Benchmarking
Its cover complete RF optimization and if any step I miss then write it in comment.