Hi,
(1)When MSC A receives Handover Required from BSC A , MSC A Should be able to Recognize this CGI,LAI are controlling by which MSC. (2) MSC B receives MAP Prepar Handover Request from MSC A , now MSC B knows which LAC and CGI are targeted,MSC B requests VLR to provide Handover Num or MSHON, at the same time MSCB asks Targeted BSC to please provide required Resources(3)BSC sends ACK also VLR Send MSHON(4) MSCB sends back MSHON to MSCA (5)MSC A now Sends IAM message to MSCB and the…
the best way to find out what is problem is to see which cause code you receive- as a brief summery–> MSCA should knows CGI and LAC of Target Cell which controlling by which MSC it is very important ,–> MSC-A should be able to analyzing MSHON sent form MSC-B to sends IAM message- check who abnormally terminated the Handover ,most properly it is MSC A
Hope it come in use