Soft Handover Overhead Reduction Possibilities

[Muhammad Imran Rafique]

Hi Experts,

our NW is currently having 44.5% softhandover overhead and we have to bring it down, following are our parameter settings.
reportingRange1a (3dB)
reportingRange1b (5dB)
timeToTrigger1a (200msec)
timeToTrigger1b (1280msec)

I need your expert opinion for optimal settings and further suggestion/recommendations.

Already we are reviewing all power and tilts in detail and will ensure minimum overshooting. Any detail report related to this subject, we will really appreciate.

BR//
Imran

[electron]

Hi Muhammad,

I think changing event trigger timers and thresholds will make your network for fast moving users unstable. I am highly recommending you do not play with parameters and keep then as default. I am quiet sure you will get optimum result via coverage optimization.

BR

Hi Experts,

our NW is currently having 44.5% softhandover overhead and we have to bring it down, following are our parameter settings.
reportingRange1a (3dB)
reportingRange1b (5dB)
timeToTrigger1a (200msec)
timeToTrigger1b (1280msec)

I need your expert opinion for optimal settings and further suggestion/recommendations.

Already we are reviewing all power and tilts in detail and will ensure minimum overshooting. Any detail report related to this subject, we will really appreciate.

BR//
Imran

[Muhammad Imran Rafique]

44.5% SHO overhead is not acceptable by any means. Its wastage of capacity of NW..... we have checked and there is no such margin via tilt/power.
If we look below TTT are very aggressive, especially to take decision to add cell in AS just 200 msec. Its very effective for call drop rate, however we are adding another RL very quickly.
Related to TTT1b 1280, we are taking much time, I think 640msec can be effective here. Anyone can share the drawbacks.

timeToTrigger1a (200msec)
timeToTrigger1b (1280msec)

In the end, if anyone can share which exactly counters can help us in identifying problematic cells/areas. I will really appreciate as we have to submit a proposal to our higher management with logical proofs.

BR//
Imran

[electron]

Was there any sentence in my reply that 42% SHO Overhead is normal?! While you did not learn to have appreciation and thanks to others time and effort to help you , you will not get your answer my friend. I have checked all of your previous posts and unfortunately this is your common attitude .Contribution should be in both directions!

Next time i will delete your posts if it continues in this manner. Good luck


Cheers

44.5% SHO overhead is not acceptable by any means. Its wastage of capacity of NW..... we have checked and there is no such margin via tilt/power.
If we look below TTT are very aggressive, especially to take decision to add cell in AS just 200 msec. Its very effective for call drop rate, however we are adding another RL very quickly.
Related to TTT1b 1280, we are taking much time, I think 640msec can be effective here. Anyone can share the drawbacks.

timeToTrigger1a (200msec)
timeToTrigger1b (1280msec)

In the end, if anyone can share which exactly counters can help us in identifying problematic cells/areas. I will really appreciate as we have to submit a proposal to our higher management with logical proofs.

BR//
Imran

[Muhammad Imran Rafique]

Honestly I am really sorry if you take it like this.

If you check my earliest posts, I do encourage everyone to participate with some constructive material. You will find few ppl, really making this informative tool as chat room. Known and obvious thing I do discourage to repeat.

related to current email, there are multiple changes been done for these timers. Even our current values are not default, these were changed 1 yr earlier to reduce drop calls. Now with call- Re-establishments, speech drop is no more headache, capacity is really critical as 2G layer is decaying.

Hope you understand my point of view. We are really thankful and you are one of the great supporter on this forum.

One should have a big heart to run a big show, ignore if anything is confusing. Your cause "SUPPORT" is much bigger than this discussion.

Take care.

[electron]

Hi,

Again i am highly recommending you to revert back event triggers to default value (I mentioned default in my fist comment) and observe the impact of reduction of SHO overhead. Make drive test for the RNC area and find unwanted fingers in Scanner for each SC and optimize coverage. You mentioned your coverage is OK and there is not much margin of improvement. Could you please share how did you verify it ?


Cheers

Honestly I am really sorry if you take it like this.

If you check my earliest posts, I do encourage everyone to participate with some constructive material. You will find few ppl, really making this informative tool as chat room. Known and obvious thing I do discourage to repeat.

related to current email, there are multiple changes been done for these timers. Even our current values are not default, these were changed 1 yr earlier to reduce drop calls. Now with call- Re-establishments, speech drop is no more headache, capacity is really critical as 2G layer is decaying.

Hope you understand my point of view. We are really thankful and you are one of the great supporter on this forum.

One should have a big heart to run a big show, ignore if anything is confusing. Your cause "SUPPORT" is much bigger than this discussion.

Take care.

[agenov]

What resource is actually affected in your network? Seems like you're talking about H// equipment, right?
Find the contributors at cell level and try to make change in terms of antenna design, cpich power, these parameters etc. on them only, if still not ok and drop is not an issue then decrease with 1dB for PS both 1a/1b as first step and see the impact.

br
alex

Honestly I am really sorry if you take it like this.

If you check my earliest posts, I do encourage everyone to participate with some constructive material. You will find few ppl, really making this informative tool as chat room. Known and obvious thing I do discourage to repeat.

related to current email, there are multiple changes been done for these timers. Even our current values are not default, these were changed 1 yr earlier to reduce drop calls. Now with call- Re-establishments, speech drop is no more headache, capacity is really critical as 2G layer is decaying.

Hope you understand my point of view. We are really thankful and you are one of the great supporter on this forum.

One should have a big heart to run a big show, ignore if anything is confusing. Your cause "SUPPORT" is much bigger than this discussion.

Take care.

[SHIVAM]

Hi Imran,

Since you are already reviewing your power (CPICH) and tilts to reduce overshoots so hope you will get improvement soon.

Meanwhile for your parameters, I believe your time to drop the pilot from active set once it satisfies event 1b (timeTotrigger1b) is too large as compared to time to add pilot into active set timeToTrigger1a . You may tune it to 640ms so as to release the degraded pilot (since event 1b is already triggered so the pilot has obviously degraded) from active set more earlier and thereby reducing SHO.

[FrankPintor]

You can certainly modify the soft handover parameters, to make it more difficult to add a cell to the active set and to release a cell more easily. The comment above regarding fast moving users is very relevant, as your new parameterisation won't be applicable to the whole network, you will have to choose areas where it can be applied without increasing the DCR.

Having said that, the timeToTrigger1a value you quote is aggressive and I agree with the previous poster saying you can reduce timeTotrigger1b. From the timer names I understand you're working with E///, just for comparison the default values for Huawei are

TRIGTIME1A	TRIGTIME1B	TRIGTIME1C
D320	D640	D640

What is your SHO minimum quality parameter? Is it already set to -18dB?

If you make these changes, I suggest you also look at increasing the active set update timer to allow the UE more time to add a cell to the active set, this should help offset any increased DCR tendency due to changing the SHO parameters.

Also, anything you can do to move traffic to HS will reduce your SHO, for example, do you have SRB over HSDPA enabled? Have you got too many PS R99 users due to HS license limitations?