Value range: 0~31, the corresponding time is 20~620s. 31 is to change the function direction of CRO on C2.
Content: Cell Reselect Penalty Time.
If the communication in a cell is affected due to very heavy traffic or some other reasons, this cell should be the last where MS works in (there is a repulse for this cell). In this case, PT can be set as 31, which causes TO invalid. C2 value is the difference of C1 and CRO, therefore, C2 value of this cell is decreased manually. MS will reselect this cell with little possibility. Besides, the network operator can set CRO according to the repulse degree to this cell. The higher the repulse degree, the larger CRO.
For the cell with very low traffic, MS should prefer to work in this cell. In this case, CRO is recommended to be between 0-20dB. It can be set according to the preference degree to this cell. The higher the preference degree and the larger CRO. Generally TO is recommended to be the same or a little more than CRO. PT is mainly used to prevent MS’s too frequent cell reselections. Generally it is recommended to be 0 (20s) or 1 (40s).
For the cell with medium traffic, generally CRO is recommended to be 0 and PT be 31 as a result of C2=C1, that is, no manual modification on the cell.
Setting of PT can effectively prevent the fast moving MS from accessing the micro-cell. This parameter can be set according to the size of micro-cell. And it is recommended to be 20s for the ordinary micro-cells. When PT is set as 31, it is used to change the direction of action to CRO.