RACH Busy Threshold

RACH Busy Threshold

For the BTS3X series and double-transceiver BTSs, this parameter specifies the level threshold for the MS random access when the BTS determines the RACH busy state. When the receive level of the random access burst timeslot is greater than this threshold, the BTS considers that the timeslot is busy. For the BTS3X series and the double-transceiver BTSs, this parameter only indicates whether the timeslot is busy. The threshold setting does not affect the normal access of the MS.

For the BTS2X series (excluding the BTS24), this parameter specifies the level threshold for the BTS to determine an MS random access.When the receive level of the random access burst timeslot is greater than this threshold and the access demodulation is successful, the BTS considers that the timeslot is busy and determines whether the RACH access is valid based on the parameter Random Access Error Threshold. For the BTS2X, the parameter RACH Busy Threshold is used to determine whether the timeslot is busy. In addition, the parameter affects the normal access of the MS. The MS access is allowed only when the level of the MS random access burst is greater than the RACH Busy Threshold.

For the BTS24, this parameter has two functions. One function is indicating the level threshold of the MS random access for the system to determine the RACH busy state. When the receive level of the random access burst timeslot is greater than this threshold, the BTS considers that the timeslot is busy. The other function is indicating whether the MS access is allowed.The MS access is allowed only when access level (including random access and handover access) is greater than the threshold.

The value of this parameter ranges from 0 to 63 (corresponding to -110 dBm to -47 dBm).

[0,63]

16

Levels

2dB

None

For the BTS2X series (excluding the BTS24), this parameter must be set according to the actual receiver sensitivity of the BTS and the minimum access level of the MS to ensure the balance between the uplink and the downlink. This parameter also affects handover access of RACH BURST during asynchronous handover.

For the BTS3X series and double-transceiver BTSs, this parameter does not affect MS access but affects the reporting of CCCH_LOAD_IND. If the level received by the BCCH on the network side is greater than the RACH Busy Threshold, the CCCH_LOAD_IND is counted once whether the decoding is successful. The RACH whose level is lower than the RACH Busy Threshold and whose decoding is successful is also counted. The measurement period is the Average RACH Load Timeslot Number.

If the value of this parameter is too small, the BTS easily considers that the RACH timeslot is busy and reports overload messages to the BSC. If the value is too great, the BTS cannot determine the status of the RACH timeslot correctly.

For the BTS24, if this parameter is used to determine busy timeslot, its setting is consistent with that in the BTS30. If this parameter is the level threshold for valid random access, its setting is consistent with that in the BTS20.

The settings of the BTS312, BTS3001C, BTS3001C+, BTS3002C, and double-transceiver BTS must be consistent with the meaning and requirement of the BTS30.

16

RACH Min.Access Level(dbm)

None

Parameters About Radio Resources

None