well… i can’t really help, but you should double check the definition of your external cells within the iBSC’s OMCR. The BSC just follows OMC-R configuration. Have you put the correct BCCH and BSIC ? The correct LAC ? Correct CI ?
I forgot to tell you that during drivetest, you should also check whether the MS measures the RXLEV of these external neighbors or not. In the SI2 and SI5 (system info msg that contain the list neighbors BCCH), do you see the BCCH of the external cells ?
If the BCCH are not present in SI2 and SI5, then it means the external cells are not defined as neighbors in the OMCR.
You can read the SI2 & SI5 in TEMS investigation “layer 3” window.
If you feel everything is correctly defined, then ask for ZTE support.
They are here to support you, aren’t they? 🙂
Let me know how it goes.