in this regard in MSS we can consider two issues:
If you have totally low PSR I suggest you work on Timer 3212 in MSS (Implicit deattach)
If the problem is limited to one or some area modify Paging method in MSS
Here is one example , with changing paging method we obtained some improvement:
LAI = xxxxxxxx
Paging type = All paging types
Priority = All priorities
Paging times = 3
First Paging duration = 6
Second Paging duration = 6
Third Paging duration = 6
Fourth Paging duration = 4
Fifth Paging duration = 4
TMSI or IMSI = First Paging with TMSI
= Second Paging with TMSI
= Third Paging with IMSI
= Fourth Paging with TMSI
= Fifth Paging with TMSI
All RAN paging = First Paging send to current LAI
= Second Paging send to current LAI
= Third Paging send to current LAI
= Fourth Paging send to current LAI
= Fifth Paging send to current LAI