CSFB Preparation Success Rate - Huawei formula

[esoestemp]

Hi experts,
Could you please state an opinion about the formula provided by Huawei in their eRAN6.0 KPI reference guide about:

CSFB Preparation Success Rate= L.CSFB.PrepAtt/L.CSFB.PrepSucc

My actual question is why the counters for CSFB from Idle are not included: L.CSFB.PrepAtt.Idle; L.CSFB.PrepSucc.Idle

Thanks in advance!

[sade]

Hi,
First of all it seems you got the formula wrong. If you want to know the SR of CSFB preparation you should divide success/attempts:
CSFB Preparation Success Rate= L.CSFB.PrepSucc/L.CSFB.PrepAtt

Secondly if you look on counter relationship in hedex, you can see that counter L.CSFB.PrepAttconsist of L.CSFB.PrepAtt.Idle + L.CSFB.PrepAtt.Emergency although it is stated in a not exactly direct way.

Finally when you look on the data from real network you may notice that those number don't add up - there is more PrepAtt than PrepAtt.Idle and PrepAtt.Emergancy combined. In my opinion we can assume that PrepAtt represents Preparation Attempts in Idle, Connected and for Emergency Call - although there is no dedicated counter for PrepAttempts in connected. So L.CSFB.PrepSucc/L.CSFB.PrepAtt is the most general look onto CSFB success rate and it incorporates CSFB's in Idle as well
If you would like to be 100% sure - you should ask Huawei