Assignment attempts (TASSATT):

The assignment attempt counter (TASSATT) is stepped in the target cell for the first assignment attempt (both successful and unsuccessful attempts) to change a connection from a signalling only connection to a TCH for speech or data. An assignment is initiated by reception of ASSIGNMENT REQUEST or HANDOVER REQUEST with cause = Directed Retry.

For assignments in the serving cell, TASSATT is stepped in the serving cell when the message ASSIGNMENT COMMAND is sent to the MS.

For intra BSC inter cell assignments, TASSATT is stepped in the target cell when the message HANDOVER COMMAND is sent to the MS.

For inter BSC assignments, TASSATT is stepped in the target cell in the target BSC when the message HANDOVER COMMAND (included in a HANDOVER REQUEST ACKNOWLEDGE) is sent by the target BSC to the MSC.

For change of channel mode, TASSATT is stepped in serving cell when assignment implies a change from signalling only to speech or data on a TCH. The counter is stepped when the message CHANNEL MODE MODIFY is sent to the MS.


Message :ASSIGNMENT COMMAND (to MS)
HANDOVER COMMAND (from target BSC to MS)
CHANNEL MODE MODIFY (to MS)

Counter :(TASSATT)
Assignment attempts (TASSALL):


The 'Assignment attempt' counter (TASSALL) is incremented for the first attempt to change a connection from a signalling only connection to a TCH for speech or data, initiated by reception of ASSIGNMENT REQUEST or HANDOVER REQUEST (cause = directed retry).

At successful assignment attempt the counter is incremented for the target cell.

If the assignment attempt is unsuccessful, independent of reason, the counter is incremented for the cell where the mobile station was tuned to an SDCCH or TCH used for signalling.

Message :ASSIGNMENT REQUEST
HANDOVER REQUEST (cause = directed retry)

Counter :(TASSALL)