Common LA between 2g and 3g

[s52d]

Hello friends!

Have you ever got some complains like:
- I have 5 bars on the phone, but got "missed call SMS"
- my batteries are running out too fast

In order to lower signalling in 2g/3g network, using common LA/VLR helps a lot.
When terminal moves between RATs in idle mode, there is no need to do location update,
thus less signalling.
As page is send to both BSS and UTRAN, there is higher probability for terminal to
catch paging message.

You can not do it if:
- you core network does not allow (pre-R4 architecture; bss and utran not on same VLR)
- you have some roaming agreements preventing it

Many networks use it. UTRAN and BSS LA must be coordinated,
but it is better to do LAU on defined border compared to low signal strength deep indoor.

There are some terminals performing badly (one brand do LAU regarless of common LA),
but it is worth doing it.

Do we use it?

BR
s52d

[electron]

Hello friends!

Have you ever got some complains like:
- I have 5 bars on the phone, but got "missed call SMS"
- my batteries are running out too fast

In order to lower signalling in 2g/3g network, using common LA/VLR helps a lot.
When terminal moves between RATs in idle mode, there is no need to do location update,
thus less signalling.
As page is send to both BSS and UTRAN, there is higher probability for terminal to
catch paging message.

You can not do it if:
- you core network does not allow (pre-R4 architecture; bss and utran not on same VLR)
- you have some roaming agreements preventing it

Many networks use it. UTRAN and BSS LA must be coordinated,
but it is better to do LAU on defined border compared to low signal strength deep indoor.

There are some terminals performing badly (one brand do LAU regarless of common LA),
but it is worth doing it.

Do we use it?

BR
s52d

Missed call alerts is one of big problem in network and at least for me still this complains as confusing me every day. Really this LAC redesign can solve the problem?

[s52d]

Missed call alerts is one of big problem in network and at least for me still this complains as confusing me every day. Really this LAC redesign can solve the problem?

Hi!
There are several reasons for missed pages. By using common LA we removed one big source.
Noticeable less complains.

Another reason is with smartphones: they like to use GPRS without user knowledge,
and without Gs or DTM, terminal is not listening to paging ch.

As there can be only one outstanding page, you are unreachable if terminal is
answering page for SMS delivery. This is commonly detected after we receive complain.

Some terminals are broken: often complain is solved by replacing terminal.

BR
s52d

[electron]

Hi!
There are several reasons for missed pages. By using common LA we removed one big source.
Noticeable less complains.

Another reason is with smartphones: they like to use GPRS without user knowledge,
and without Gs or DTM, terminal is not listening to paging ch.

As there can be only one outstanding page, you are unreachable if terminal is
answering page for SMS delivery. This is commonly detected after we receive complain.

Some terminals are broken: often complain is solved by replacing terminal.

BR
s52d

As i understood as per your experiences there are 3 major category of problem:

1. LAC problem which when you used same LAC big impact of improvement of missed call alert you have observed.

2. Gs interface between MSC/VLR and SGSN can help to decrease teh problem

3. If we received complain from a single user we can be suspect to his/her UE and if in a area several user has given complaint we can reject UE problem


Did i get the point?


Thanks

[s52d]

>As i understood as per your experiences there are 3 major category of problem:

>1. LAC problem which when you used same LAC big impact of improvement of missed call alert you have observed.

Yes.

>2. Gs interface between MSC/VLR and SGSN can help to decrease teh problem

Yes. If problem is due to GPRS activity during CS page.

>3. If we received complain from a single user we can be suspect to his/her UE and if in a area several user has given complaint we can reject UE problem

Ah, this is not common. But happens. I guess more common is missed page
due to receiving of SMS in the same time.

>Did i get the point?

Yes. What really helps is to take traces and analyze specific cases.
There are many resons. And for many reasons we could not found a cure.
Sometimes people are out of coverege ;-)

Years ago fo found out: half of missed pages was generated by SMSC.

[salamanda1969]

Dear friends,

Just curious to find out your experiences with common 2G/3G LAC.

1. Were there additional LA split in your RNC/BSC after implementing common 2G/3G LAC ? This could be caused by significant increase in 2G paging, because the 3G network (RNC/NodeB/PCH) has higher capacity than 2G. When the quantity of 3G smartphones increases, does 2G paging increases unnecessarily ?

2. Typically a 2G LA is smaller than 3G LA (because 3G paging capability is larger). Does that mean the size of 3G LA has to be reduced to match the size of 2G LA, so that we can achieve common LAC and avoid inter-system LU (due to different LA) ?

3. If a user is missing pages and complains to the operator, is it easy to troubleshoot the root cause (2G or 3G issue) ? I'm guessing call trace and unique 2G/3G cellid helps. Are there other challengese in troubleshooting ?

4. When a LA split is required on 2G, does that mean the 3G LA must also be split ? Creating more LA will increase LU across LA. Does increased LU signalling (RRC, SDCCH resources) cancel out the 'savings in inter-RAT signalling ?

Ideas for thoughts. Thanks for reading.

[s52d]

1. We followed BSS LA plan. Now we use both 2G and 3G stats to do changes.

2. Indeed. But, we trade LAU everywhere (indoors) to LAU in controlled areas and good signal.
Imagine Z1010 doing few thousand LAU indoor, where both 2g and 3g coverage is bad.
I prefere to have full controll where it happens.

3. Hard. You can not get trace on terminal not responding to page - but you can see if
terminal is receiving SMS or doing LAU at the same time.

4. See 1. Anyhow, you still have RAU...

As good old SDCCH dimensioning guideline says (after 30 pages of theory):
- check stats. If you need more, give more. If it is too much, take away.

BR
s52d

Dear friends,

Just curious to find out your experiences with common 2G/3G LAC.

1. Were there additional LA split in your RNC/BSC after implementing common 2G/3G LAC ? This could be caused by significant increase in 2G paging, because the 3G network (RNC/NodeB/PCH) has higher capacity than 2G. When the quantity of 3G smartphones increases, does 2G paging increases unnecessarily ?

2. Typically a 2G LA is smaller than 3G LA (because 3G paging capability is larger). Does that mean the size of 3G LA has to be reduced to match the size of 2G LA, so that we can achieve common LAC and avoid inter-system LU (due to different LA) ?

3. If a user is missing pages and complains to the operator, is it easy to troubleshoot the root cause (2G or 3G issue) ? I'm guessing call trace and unique 2G/3G cellid helps. Are there other challengese in troubleshooting ?

4. When a LA split is required on 2G, does that mean the 3G LA must also be split ? Creating more LA will increase LU across LA. Does increased LU signalling (RRC, SDCCH resources) cancel out the 'savings in inter-RAT signalling ?

Ideas for thoughts. Thanks for reading.