Expert solution for PS Call Drop Rate

[tukangoptim]

Here in this thread, i would like to call all expert from any vendor to discuss solution for improving PS R99 & HSPA Drop Call Rate.
Any guideline, technique, feature trial, finetuning, report etc, is highly appreciated!

[eino]

please specify vendor

[oswe]

ok, if the percentage suggests you that this is a coverage issue... then you have to start checking all tilts and optimize this if you have the electrical tilt facility. plus, depending on the vendor, study prach attempts coverage (huawei allows it and NSN also...)...
features like CELL_FACH will also have an impact on your ps drop... I will try to remember some other things...

[anas.k3]

For the PS Drop it depends on the issues you have Many actions can lead to improve the PS drop : Neighboring cleaning, RTWP tuning and fix, Coverage issues for this you can tune the IRAT parameters even by cell level, increase timers for RL reset.
As i said before you need make anlysis to your network and work and the most affecting aspect.
Hope my answer can help

[tukangoptim]

For the PS Drop it depends on the issues you have Many actions can lead to improve the PS drop : Neighboring cleaning, RTWP tuning and fix, Coverage issues for this you can tune the IRAT parameters even by cell level, increase timers for RL reset.
As i said before you need make anlysis to your network and work and the most affecting aspect.
Hope my answer can help

interesting.., tell me pls what is the meaning of rtwp tuning ? any guideline or success story ?

[anas.k3]

interesting.., tell me pls what is the meaning of rtwp tuning ? any guideline or success story ?

The RTWP can be tuned on free hour the normal value is around the -105. It can be affected by the AIR system (antenna, TMA,..), interference, outpout power and also some settings to tune like the Rx attenuation that must be same value Main and diversity and also depending on the site type (feeder & connector loss).
Many guides have been already shared on the Forum about the RTWP troubleshooting you can check.

Keep us informed about your PS drop rate ;)

[kammola2008]

Thanks for valuable info

[MHDRF]

hi, if the drops mostly tends to be for RF reasons the first thing to do is tuning antennas tilts and azimuths if applicable, neighbors list cleaning is too important, and once on Huawei turning on the DCCC for up link stability did a nice enhancement.

[sofianonline]

Do you know fast dormancy setting in your network?Sometimes, T1 & T2 set in too high value which cause RAB still hold by user even if it's not used.Just try to decrease the timer and it will reduce your RRC Rejection due to RF Fail in dramatically.But you should also check your CPU load in SPU RNC and GTPU SGSN because its value will increase due to high signaling.

[a19997104]

playing with inactiviry timer can improve PS drop, huawei default is 20, change it to 12, PS drop rate decreases

[marcengo]

Well, being on the operator side, we were always afraid of any kind of drop ratio increase, however, sometimes you have raise the drop ratio to getter better results somewhere else. For example, the inactivity timer. It is controvertial, but, in my opinion, reducing it will only mask the drops problem. You´re literally disconnecting the UE before it drops. It makes sense, on a KPI-oriented view, but the problem is still there. Also, this may impact on the signaling load. UEs going to early to idle may increse the amount of RRC Connection Attempts due to terminated calls, meaning that, the UE went to idle before a transmission was over, or the internet has something to deliver to the UE- something quite common today on smartphones, running WhatsApp, Facebook, Viber and etc... Where I work, we strongly suggest to raise the timer to something like 1800s, to avoid unecesary signaling. What`s the coletheral effect? Higher probability of call drops and higher utilization of the CELL/URA_PCH channels.


Actually, there´s no secret formula to solve anything on the cellular world, there is always an "if", or a trade off, you need to fallow your guts, young padawan!