T_MSRFPCI is started in the BTS on receipt of the CHANNEL ACTIVATION ACKNOWLEDGE
message for a TCH. Its purpose is to observe the receipt of the MPRCI message, i.e. it is stopped when
the MRPCI message is received. The BSC sends this message when the MS has successfully sent the
first layer 3 message on a new channel during call setup (CM SERVICE REQUEST (for the SDCCH)
and ASSIGNMENT COMPLETE) and handover (ASSIGNMENT COMPLETE (intracell HO) and
HANDOVER COMPLETE (inter-cell handover)). As T_MSRFPCI is hardcoded to a very long value
(20s), this timer should never expire under normal conditions and reasonable timer settings.