Number called B not responding the first time, only on second dialing

[Arsalan_Wasti]

Hello all.

We are having a issue in our 3G network.

Most of the time when we call the party B we get number not responding recording even though the number of party B is ON.

After dialing twice the number gets the call.

Is there some config relation thing that needs to be checked?

[Ayubkhan90]

In which network?

[Arsalan_Wasti]

3G network.

[javiersapon]

@Arsalan_Wasti

Is there some config relation thing that needs to be checked?

Paging is not working.

Is it only in one cell?

Check paging discard counter at RAN side.

If paging is success, then check access failures in RRC, mobile terminating call.

[Mohamed_Hassan]

@Arsalan_Wasti

Is there some config relation thing that needs to be checked?

You need to do traces to get the full image.

In your case, it could be one of many issues, including:

1. Weak Uplink coverage, or high RTWP in this area.
2. Paging timers issues, if the paging timer is too strict it might not be in the paging frame.
3. It could be from the core side as well, if the signaling is not going well.

To get a good idea, try the following:

1. Check the area effected by this phenomena (single site? a cluster? a whole RNC?)
2. Check the KPIs of this area (RTWP / Paging counters)
3. Check with Core team for further analysis from their end.

[Arsalan_Wasti]

@javiersapon

Is it only in one cell?

Check paging discard counter at RAN side.

Thanks!

Most of the cells has this issue.

[javiersapon]

What is the vendor? Huawei, Ericsson?

Check pagingDiscard counter.

[Arsalan_Wasti]

Huawei.

[maliseker]

@Arsalan_Wasti

Most of the time when we call the party B we get number not responding recording even though the number of party B is ON.

After dialing twice the number gets the call.

Number not responding or not reachable?

[Arsalan_Wasti]

@maliseker

Number not responding or not reachable?

Not responding.

@Mohamed_Hassan

Weak Uplink coverage, or high RTWP in this area.

RTWP is fine.

@Mohamed_Hassan

Paging timers issues, if the paging timer is too strict it might not be in the paging frame.

Let me check the paging time.

@Mohamed_Hassan

Check the area effected by this phenomena (single site? a cluster? a whole RNC?)

It is happening on multiple cities with multiple RNCs.

[Ayubkhan90]

@javiersapon

Paging is not working.

Agree.

We have done analysis of the same issue in our network, and from traces, we found that paging no response was the reason behind it.

It might be paging congestion or something related to Core issue.

[Mohamed_Hassan]

@Arsalan_Wasti

RTWP is fine.

If UL interference is good, it’s highly suspected to be paging issues.

Try to get the sites by their LACs (if LACs are not well divided, or in a the diviosn in high signaling areas), and do paging KPIs drilling down.

[Arsalan_Wasti]

Are these enough or should I add more?

Or this cell wise paging KPIs:

[javiersapon]

@Arsalan_Wasti

VS.RANAP.CsPaging.Loss

If that one is 0, then you need to check at MSC level, the counters.

[Arsalan_Wasti]

for 10 days…

[javiersapon]

Check the RRC success MT.

RRC attempt - RRC success for mobile terminating cause

[Arsalan_Wasti]

It’s not present in this template. Let me extract the other one.

[RFSpecialist]

RACH success rate would count as well.

[Arsalan_Wasti]

@RFSpecialist

RACH success rate

RACH Utilization %

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IU Paging Congestion Ratio (Cell)(%)

VS.RRC.Paging1.Loss.PCHCong.Cell

[victor_kudidissa]

@Arsalan_Wasti

Is there some config relation thing that needs to be checked?

CSFB?