I have been having some problems by performing 2G to 3G handover in a mix scenario (2G belong to Alcatel-Lucent while 3G is Ericsson). I have set all the parameters from 2G network in order to execute the process but it is not working properly.
The only way the handover process works is when the call is initiated on 3G Node B, then handed over to 2G network (this process works just fine) and then come back to 2G, so the sequence should be 3G to 2G to 3G. If I initiated the call on 2G and I try to do the handover to 3G it doesn’t happen.
Another thing that is relevant is the fact that 2G parameter (Alcatel-Lucent) EN_2G_3G_NO_SERVICE_HO need to enable to perform the handover.