---Low Availability
Action: Check SDCCH Availability. Check if the channels are manual, control or automatic blocked.
---Increasing Traffic Demand
The high traffic could be related to an occasional event or due to a long term growth.
Action: Check if short term traffic growth. Make trend comparisons. Check if combined SDCCH is used. Check SDCCH dimensioning.
---Bad use of Adaptive configuration of Logical Channels
By using the Adaptive configuration of logical channels feature, the basic SDCCH configuration in a cell will be under-dimensioned. If this feature is not used correctly, it will cause SDCCH congestion.
Action: Check if ACSTATE is on. Check parameters related to Adaptive configuration of logical channels
---Long Mean Holding Time
If the mean holding time is long, this generates a higher traffic load.
Action: Check SDCCH Mean Holding Time
---Too Frequent Periodic Registration
Action: Check Random Access Distribution. Check the timer T3212 in the BSC and the parameters
---BTDM and GTDM in the MSC
Solution: Decrease the periodic registration.
---Location Area Border Cell
If the cell is situated on a misplaced Location Area border, this means that unnecessary many normal LUs are performed.
Action: Check site position and location area border. Check Location Update Performance. Check parameter CRH etc.
---Extensive SMS Usage
Extensive SMS usage increases the SDCCH traffic and could cause congestion if badly dimensioned SDCCH channels.
Action: Check SMS activity.
---Cell Broadcast Used
Action: Check if Cell Broadcast is active. .If active, check if it is used by the operator.
---IMSI Attach/Detach in Use.
An introduction of IMSI attach/detach will increase the traffic on SDCCH. However, the benefits are that the paging success rate will increase. The recommendation is to use Attach/Detach.
---Cell Software File Congestion
Action: Check SAE setting. High Ratio of Random Accesses
Action: Check Random Access performance