This is what i have here in B10 :
MC14a: NB_TCH_DROP_HO_PREP_EXEC_FAIL_BSS_PB_PM110:
Number of TCH (in HR or FR usage) drops due to BSS problem during any TCH handover preparation and execution phases. This counter is incremented on the cell on which the problem occurs(In the case of internal inter-cell handovers, it is not incremented on both serving and target cell). For problems that are not related to a specific cell, the counter related to the serving cell will be incremented. It may happen that several causes of failures mentioned below are detected consecutively. In that case, the counter will only be incremented once, as soon as the handover procedure fails. This counter takes into account handovers from TCH in traffic or in signaling mode. 1) Whenever the BSC receives on Abis interface from the target cell negative acknowledgment to the TCH channel activation involved in the handover procedure. 2) Whenever the timer supervising the Channel Activation procedure (T9103) expires on the target cell during activation of a TCH channel involved in the handover procedure. 3) Whenever an 48.058 ERROR REPORT message with a cause value of “OandM intervention” is received on Abis interface from either the serving or the target cell during the external or internal inter-cell handover procedure and leads to a transaction failure. 4) Whenever an 48.058 ERROR REPORT message with a cause value of “OandM intervention” is received on Abis interface on either the old or the new channel during the internal intra-cell handover procedure and leads to a transaction failure. 5) Whenever an 48.058 ERROR REPORT message on SAPI 0 with a cause value of “message sequence error” is received on Abis interface from the serving cell between the sending of the 48.058 CHANNEL ACTIVATION message and the reception of the 48.058 CHANNEL ACTIVATION ACKNOWLEDGMENT during the internal inter-cell TCH handover and leads to a transaction failure. 6) Whenever an 48.058 ERROR REPORT message on SAPI 0 with a cause value of “message sequence error” is received on Abis interface on the old channel between the sending of the 48.058 CHANNEL ACTIVATION message and the reception of the 48.058 CHANNEL ACTIVATION ACKNOWLEDGE during the internal intra-cell TCH handover and leads to a transaction failure. 7) Whenever a LAPD failure related to either serving or target cell is reported to the Layer 3 of the BSC (for an RSL supporting a TCH transaction for handover purpose) and leads to a transaction failure. 8) Whenever an TCH handover abortion is initiated by the BSS OandM FAULT MANAGEMENT application part or by the BSS TELECOM application part as the result of a system defense action which may be due to BSS equipment failures external to the BSC (e.g. RSL failure or CU recovery failure), or due to BSC internal hardware problems (e.g. TCU failure or DTC failure) or due to BSC internal software problems (e.g. inconsistencies detected between software modules or lack of software resources (memory, timer reference, file reference…) or communication problems between different processor boards). 9) Whenever a 48.058 CONNECTION FAILURE INDICATION message with a cause value of “remote transcoder failure” is received on Abis interface from the old channel between the sending of the 48.058 CHANNEL ACTIVATION message and the reception of the 48.058 CHANNEL ACTIVATION ACKNOWLEDGE during an internal intra-cell or inter-cellTCH handover procedure and leads to a transaction failure. Notes : 1. TCH handover failures which are due to OandM operator actions on BTS or BSC should not be counted. Indeed, in case of numerous failures due to OandM commands, this counter will overestimate failures which are due to problems which are internal to the BSS. However, due to the current implementation which does not allow to be aware of the origin of the failure, OandM operator actions will also be counted. 2. It may happen that the counter can not be incremented since it is implemented within the faulty entity.