NO HANDOVER ATTEMPT made by party-A ? It doesn’t sound like anything i know…
I assume you’re looking at a drivetest tool, at the “event” screen ?
Could you rather check the layer-3 messages ? That will give us more details about what’s really happening.
Is there a HO COMMAND in downlink for example ?
did this problem happen all the time on different MS, or did it just happen once ?
does it happen also when the call is in a cell with good quality, and a HO shouldn’t take place ?
It’s incredible that the Handover algorithm (located in the BSC) is impacted by DTAP messages which are transparently routed between MSC and MS.