3g optimization using drive test data

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Copyright 2008 AIRCOM International

Aircom IQ

3G Optimization using Drive Test Data


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Possible Optimisation Processes

Overshooting Cells\ Pilot Overshooting

Pilot Pollution

Poor Coverage Levels (Poor Dominance)

Interfering Coverage

Pilot Surprise

Missing Neighbours


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Overshooting Cells\ Pilot Overshooting

Overshooting refers to excess coverage levels\range of a cell, i.e. Cell pilot power is detected far (how far?) from its origin Cell pilot power is detected beyond first\second tier neighbouring sites

Overshooting Cells can be detected by the following logic For every measurement point, calculate the distance (to all detected cell) and

the average distance Report on those cells which are above or X times the average distance

Further enhancements can be made by considering Different distance criteria based on site density\area type, e.g.

mean distance < 1km overshooting cells three times the average distance mean distance > 1km overshooting cells two times the average distance

Only consider measurement points having three or more detected cells A cell has to appear at least X number of times to be considered as over

overshooting


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Overshooting Cells- RNC TBRNC10 Cluster 327

Scrambling Code # detectedMS-1

Scrambling Code # detected-MS-3

307 53 307 8

84 48 84 21

46 31 46 1

91 29 91 1

260 22 260 13

17 19 17 10

47 11 47 4


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Overshooting SC 307 (Appeared 57 times)


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Overshooting SC 84 (Appeared only 20 times)


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Overshooting SC 260 (does not make sense)


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Pilot Pollution

Pilot pollution can defined as the regions where the number of detected cells are greater than the Active Set (AS )size and also above the AS activation Ec/Io threshold

Pilot polluters can be detected by the following logic

Only consider those measurement points where the number of detected cells > 3

Further filter the measurement points where all cells are detected above an Ec/Io threshold of X dB (-12) and not below Y dB (e.g. 10) of that of the best cell

Measurement points extracted by the above criteria contain the pilot pollution information, i.e. the first three cells belong to active set and rest pilot polluters

3g optimization using drive test data

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