Is there a way to map neighboring ENBs from traffic analysis using S1 interface only? I want to know per ENB which ENBs can he handover to without analyzing X2 traffic, I know that there are S1 procedures such as S1_HANDOVER_REQUIRED(S1 handover) and S1_PATH_SWITCH_REQUEST(X2 handover) that are part of the S1/X2 handovers, the problem is that most of the handovers are done via X2 interface(only when failed it is done via S1) and S1_PATH_SWITCH_REQUEST does not contain source ENB information so I can't create the mapping in most cases from just stateless traffic analysis. Are there maybe some procedures that contain list of neighbor ENB ids?