What are the possible ways to shift traffic from GSM 900 to GSM 1800?
And what is the recommended?
GSM 900 is congested while GSM 1800 is unused.
2 Likes
Here are some tips for Huawei (but must apply to other vendors, as they are GSM concepts):
TA:
One first thing, check the traffic in both bands and its distribution versus TA.
LAYER:
If TA distribuiton is fine (almost the same), you can set layer priority (smalllest number means higher priority).
In your case, for traffic shifting from GSM 900 to GSM 1800 you can set GSM 1800 as layer 2, and GSM 900 as layer 3. GSM 1800 will have higher priority and will absorb more traffic.
Inter-layer HO Threshold:
Also, you can decrease Inter-layer HO Threshold for GSM 900 cell. When the downlink level of a cell is lower than this threshold, the cell takes low priority in handover algorithm.
If you increase it, traffic/congestion will decrease.
CRO:
You may also increase CRO (Cell Reselect Offset) in GSM 1800. For example, change PT=0 (PENALTY_TIME)
This is because after cell selection, MS will reselect another better cell in idle mode. Reasonable setting of this parameter can reduce handover times and realize assignment to a better cell. Usually it is not set as larger than 25dB. Generally the cells with the same priority in the network have basically the same CRO.
Edge HO Thresholds:
Lastly, you can restrict Edge HO Thresholds on GSM 1800.
Hope that helps.
8 Likes
A very Good Description Sir!! Appreciated!!
the last 3 ones are valid only when the target cell has just 1800 band (and is not a concentric cell). am i right or not?