How to improve Hand Over Success RateIt is very important to maintain correct neighbour plan and do the basics. If you do not follow the

basics of neighbour planning, it is very limited to possibilities to improve HOSR by using parameters.

Edge, Layer, PBGT, Quality or Load sharing handovers will not work properly if we do not have

correct neighbour plan. Therefore we must work on HO basics as the first step to improve HOSR.

1). Define correct neighbours

Still it is found many neighbour relations are missing even co-located neighbours. Initially we can

find missing neighbours by using Nastar. After that we should work on tools available in BSCs which

give you real HO requirements in the field (Undefined Adjacent Cell Measurements in BSC32 and

Neighbour Cell Optimization tool in BSC6000, unfortunately still we are not able to use these tools

available with the BSC6000 & M2000).

2). Method of removing neighbours

Based on HO statistics, this is the best and only method that I suggest to remove neighbours. We

can remove HO relations which have fewer no of HOs and cells having poor HOSR, but it depends

on the importance of the neighbour to avoid call drops). Further Nastar is not a good tool to remove

neighbours.

3). Same BCCH & BSIC combinations

Avoid same BCCH+BSIC combination is very important to improve HOSR. In this case it is better to

keep maximum possible distance between same BCCH+BSIC combinations. I recommend keeping

6km distance in urban area. Again this checking should be done periodically since many new sites

become on-air time to time.

4). External neighbour parameters

This is very important since there are many BSC borders in the City area. Many hand over

improvement can be achieved in the city area by improving inter BSC HOSR. This external

neighbour parameter checking has to be done periodically.

4). Frequency plan

Co-channel interference degrades HOSR. Proper neighbour relations will increase HOSR while

improving all other KPIs such as CDR, Congestion and CSSR. I expect your support to improve

HOSR by following above steps.

Mobile Communication Basics -External Cell ParametersIt is required to define correct data in external cells to have a proper inter-BSC handovers & inter-

MSC handovers, especially values of Layer, Layer Threshold and Minimum DL Power of the

candidate cell. This might be happened after the cutovers or wrong initial configuration by BSS

team. Anyhow this will cause poor HO performance while increasing call drops. Further it will affect

traffic balancing in border cells as well. Therefore we should give more priority to maintain correct

external cell data inside the city area since there are many BSC borders. Therefore, it is better to

give more priority to maintain correct external cell parameters.

Parameters mentioned in below tables are required to be checked such as layer, layer threshold,

cell priority and Min DL level on Candidate Cell parameters of external cells. Concept behind this

is external cell parameters must be equal to original cell parameters. In this case, your BSC’s

external cell parameters should be equal to neighbour BSCs original cell parameters

BSC6000

2G External Cell Name

BCCH No.

MNC

MCC

LAC

CI

NCC

BCC

Whether to Share MSC

Layer Where the Cell Is Located

Priority Level of Cell

Inter-layer Handover Threshold

Speed Penalty Value

Speed Penalty Time

Minimum DL Power of Candidate Handover Cell

When to check

After a BSC cutover

After define new neighbour plan

After change frequency plan (BCCH+BSIC)

After implementing a new LAC plan

After change other parameters which mentioned above (it is better to do external cell parameter

audit at least once every 2 week since it is difficult to monitor all these parameter changes in

daily basis)

How to check

Using Excel vlookup function

Nastar – import autocfg files of neighbour BSCs and your own BSC and run “Frequency &

Neighbour Config. Para. Check”