Not enough SDCCH capacity (define more SDCCH TS !!)
Enough SDCCH capacity, but
1- some TRX’s are down, so the SDCCH timeslots defined on thos TRX are down as well.
2- there is a lot of sdcch traffic
a) due to SMS
b) due to location updates
c) due to too many call attemps
–> can you send the MS in idle mode to camp on other neighbor cells ?