Gsm bss network kpi (sdcch congestion Rate) Optimization Manual

Causes	BSC-Level
Cell-Level
Traffic Load	Help of Performance Counter Reference > BSC Measurement > Access Measurement per BSC SDCCH Congestion Rate (overflow) (%) ZK3004: Traffic Volume on SDCCH per BSC	TS3010: Traffic Volume of Signaling Channels (SDCCH) CS3010: MRs on Signaling Channels (SDCCH) CS3023: Traffic Volume of Speech Service on SDCCH CS3024: Traffic Volume of Short Message Service on SDCCH CS3025: Traffic Volume of USSD Service on SDCCH

All the services such as location updating, MS attach/detach, call setup, short messages are performed on the Schiff a certain service causes burst traffic, the SDCCH congestion may occur.
In this case, check whether the abnormity of Channel Requests, Successful Immediate Assignments or Successful SDCCH Seizures is caused by the service of location updating, MOC, paging, or short message. Note that you should check the history traffic statistics when querying these traffic counters to see whether they fluctuate during a certain period.
The traffic counters related to the SDCCH request and seizure are listed in the following table. By analyzing these counters, you can find out the reason why congestion occurs in the network or cell.
If the SDCCH congestion is caused by certain burst services such as location updating and short messages, use the following methods according to the specific configuration of the BTSs.
a. For the BTS with multiple TRXs, enable the SDCCH dynamic allocation function or increase the number of SDCCH channels.
b. For the cell with only one TRX or without extra channels, enable the immediate assignment procedure. In the immediate assignment procedure, the TCH is immediately assigned when the SDCCH has no available resource during the processing of access request.
c. Increase the number of TRXs.
It is difficult to avoid the SDCCH congestion caused by network burst services; however, you can take some relief measures such as increasing the number of SDCCHs or enabling the SDCCH dynamic conversion function.
Some counters related to burst services of the BSC6000 are listed in the following table.