Why and how to solve Irat HO problem of some smart phone: BB, Iphone, ..

[Interface]

Hi all guides,
At last week, we found an serious problem: some kinds of smart phone can make Irat HO from 3G to 2G. Our network used E\\ equipments. And I think that this error very population in other network. Why and how to solve this problems - I send at the attached file. This is special case and effecting to large number of customer. Please click thanks button if you think that this thread is useful.

Pass: interface

[uel888]

I believed that problem also exist in blackberry.

[Interface]

Yes, this problem happen to both Iphone, BB and some Nokia, Samsung kinds.

[scorpion]

Hi All,

Even in IDLE Mode The BB handset never comes back to 2G Properly.

BB Handsets subscriber using NET1 makes to phone to try in to NET2, But NET2 rejects the LU with "Roaming barred in this LAC", But the phone never falls back to NET1.

[s52d]

Hi All,

Even in IDLE Mode The BB handset never comes back to 2G Properly.

BB Handsets subscriber using NET1 makes to phone to try in to NET2, But NET2 rejects the LU with "Roaming barred in this LAC", But the phone never falls back to NET1.

Some BB terminals have problems after 2g to 3g handover: speech is garbled in one way only.
All OK after handover back from UMTS to BSS.
It is persistent over several SW upgrades both UTRAN, MSS and BSS. All three are E///.
No sollution yet: we just restricted 2g to 3g handovers heavily.
It is not signalling: we suspect cyphering, but no real root cause has been found so far.

BR
s52d

[twenty8]

Hi, I tried to download the attachment but it gave some errors , any idea why ?

[zeldalcl]

Hi all,
I have seen the same problem. Some smart phone (sample BB, Iphone...) uses XUDT message when handover. If your network use UDT only, handover from 3G-2G of the phones will drop.
I think it's important for you.

[s52d]

Hi all,
I have seen the same problem. Some smart phone (sample BB, Iphone...) uses XUDT message when handover. If your network use UDT only, handover from 3G-2G of the phones will drop.
I think it's important for you.

Hi, not for me. We are XUDT for many, many years.
Drops on IRAT ho is not a problem: my problem is (probably cyphering) inconsistency
with certain old BB terminals, causing unidirectional garbled speech after 2g to 3g
handover.

Quick workaround: do not use 2g to 3g active mode handovers. Aaaargh.

BR
s52d

[fon909]

Hi,

is there a command to find the feature UDT to XUDT in E///?

[fon909]

Please suggest how to check whether this feature is active?

[Interface]

Please suggest how to check whether this feature is active?

You can check this feature at MSC of E\\. The command to check this: please find it in the Alex Library.

[jimjim]

Hi all,
I have seen the same problem. Some smart phone (sample BB, Iphone...) uses XUDT message when handover. If your network use UDT only, handover from 3G-2G of the phones will drop.
I think it's important for you.


Hello there,

Are these UDT and XUDT special messages used for E/// equipments, or these are standard messages for WCDMA.

:)
Regards,

[Interface]

Hello there,

Are these UDT and XUDT special messages used for E/// equipments, or these are standard messages for WCDMA.

:)
Regards,

No, I think that you are understand wrong this problem. This is an topology for message processing of MSC before this message is transmitted.
With HW, the default value is XUDT, other vendors used UDT.

[boring]

No, I think that you are understand wrong this problem. This is an topology for message processing of MSC before this message is transmitted.
With HW, the default value is XUDT, other vendors used UDT.

thanks for the thread. very useful but i have a question.
the use of UDT/XUDT is something which is related to SS7-SCCP of MAP protocol which is transparent to the type of phone being used.
can you say in more details (if you have found actually) what was the problem?

[scorpion]

I belv XUDT is enabled per signaling relationship or for entire network ?...how the roaming/sms performance towards other networks ?