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

    thinking optimization

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.