SDCCH DROPS

Hello Patrick,

if you using ericcson bts,and
you want to reduce SDCCH Drop, trying to push SDCCH allocation to Channel Group 0. check the BSC properties for maximum SDCCH allocation per TRX and after that you can reduce paging load with adjusting MFRMS value.

Dear Patrick,

What we have to know is the difference between fail & drops.

SDCCH Fail ==> it simply means that channel SDCCH hasn’t seized the TImeslot in TRX. It’s sometimes due to SDCCH Congestion, TRE Faulty which carries SDCCH TS or even bad SDCCH TS in TRE.

SDCCH Drop ==> it means that SDCCH channel has seized SDCCH TS in current TRX, but due to bad radio condition (Qual, Interference), then this channel drops. It’s also due to BAD SDCCH TS.

I suggest you to re-allocate SDCCH TImesot to another TS. Remember to pur the SDCCH TS not in TS0.

Cheers,

Paul C S

Dear Ikbel,

Parameters which influenced SD drops : SDCCH Drop HO + SDCCH Drop radio + SDCCH Drop BSS

How to reduce SD Drops : you have to find out whether it is from radio, HO or BSS.

For radio, you should try to check first the TRE which has SDCCH Channel (ussually TRX 1). Then try to change SDC allocation to another TS.

What equipment do you handle? ALcatel, Ericsson?

Unfortunately, in Alcatel, I haven’t found an indicator that shows us the most SD Drops TRX contributor.

Also please check the Interference Level, either in UL or DL.

Best regards,

Paul C s

Ak

Actually it is not db it is dBm

The difference between dB and dBm is;

dB is relative to a specified unit, and also dimensionless because values are divided (watt to watt for example)

dBm is absolute value and “m” is for “microwatt”

there are more decibel units, for antennas dBi is used and here i is for “isotropic”, gain of antenna is defined relative to isotropic antenna.

so minus corresponds a watt value actually you can calculate it or convert and find corresponding value.
decibel is used because using “watt” makes things complicated so many digits so decibel makes things simple

How about siemens equipment?

Hi Prashant,

“tch” is traffic channel and it uses for carry the user information either voice or data.

Hello Brother, can you give me a formula that relates dB and dBm. I also like a detail explanation of the difference between the two units. Pls throw more light on the negative sign that always preceeds dBm. Thank you