RACHBT in Handover ?

Hi Santo,
RACH busy threshold, defines a threshold for the signal level on the RACH. The general purpose of this parameter is to define a minimum level criterion a received RACH signal must fulfill to be regarded as a real RACH access.
BTS continuously observes the signals received on the RACH slots. As even without any MS RACH access there are always at least some ‘noise’ signals on the RACH slots. The layer 1 subsystem is to evaluate the received signal with respect to specific criteria, e.g. it measures the receive level and checks if it exceeds defined minimum.
The value entered for parameter RACHBT is not only relevant for the CHANNEL REQUEST message on the RACH but also for the HANDOVER ACCESS message on the FACCH! The level evaluation
of RACHBT against the receive level of the handover access burst on the FACCH is exactly the same as for the RACH. Thus, the setting of RACHBT also has an influence on the handover success rate.
From my experiences, value of RACHBT has big impact to the SDCCH Drop rate.
BR
Tomar

dear sera
the RX lev Acce min is the parameter which affect after you initiate call ( affect path loss C1)and it value is different than RACHBT
which it is very high than first one.

Hi Sera,
Try to read my article once more. The RXLEV Access Minimum is SysInfo broadcasted on BCCH. And mobile make decision, of received signal is for particular cell is above/below this threshold. The cell level is suitable or not for access. If the RXLEV is stronger than this defined threshold RXLEVACCMIN, than mobile could try to make Random Access on RACH channel. In the BTS is defined RACHBT. If the received RACH access (in the BTS) is below this threshold, than this random access is discarded.
In Siemens is one counter, which counts number of discarded attempts. Set RACHBT according to BTS sensitivity. For proper settings of RACHBT, this counter could indicate wrong path balace.
BR
Tomar

hi tomar,
i need to know the impact of the FACHBT on the handover,if it’s possible to give me the treshold