2G/3G Co-LAC

[justdream]

Dears,

From your practical experience, what do you think about having Same lac for both 2G/3G?
I didn't try it before, so I appreciated your feedback based on practical trial

[srilasitha]

This is something we also planned to do

In theory this should improve Paging success rate. but needs to both needs to be in same MSC

[plannerguy]

Hi

As per my understanding its not possible with NSN domain. Reason being we have some definitions to be done at CORE end regarding the LAC pertaining to RNC and BSS entities.

So there is possibility of conflict in definitions. also there is chance of paging wrongly routed to different domain.

Rgds
Plannerguy

Rgds
Plannerguy

[s52d]

IMHO: first networks in my area were using common LA for 2g/3g with NSN core.
Please note: this is pure core network functionality: both BSC and RNC do not need to know about common LA.

Years ago this was main obstacle: in well organized and structured operator, there is no way to make such change.
Too many people involved, resisting change by principle and not understanding benefits.
Another one: some silly national roaming agreements where different LA is mandatory.
Of course, common VLR is a must.

Benefits are not just theoretical: most of the networks use today common LA.
It is more reflected in customer complains as in pure paging stats.

Again: if common LA is not used, then terminal has to register each time RAT is changed.
Untill VLR is properly updated, pages are routed to old LA/RAT.
It takes some 10 seconds when terminal is unreachable.

BR
s52d

[akram]

if someone have remaining courses rather GSM,GPRS,UMTS, intro from ossidian please upload it

[Amr Harby]

It's very useful in improving paging success rate , reducing the number of location updates .... you just need to randomize the cell ids for both 2G and 3G together .... make sure that no cell id is comman in 2G and 3G , redesign your LAC areas to be smaller geographically... and to have MsC in pool for both 2G and 3G .

[JCarlos21]

Hi justdream,

I hope you find relevant this thread already made about Common LAC between 2G/3G:

http://www.finetopix.com/showthread.php?11554-Common-LA-between-2g-and-3g&highlight=

Best regards,

[yafawi79]

I just like to mention that there is a technology that allow to have 2G/3G and even 4G in one node which called Single RAN. (SRAN). all the equipment and site will have the same LAC since they all will be connected to one core network. Thanks

[justdream]

I just like to mention that there is a technology that allow to have 2G/3G and even 4G in one node which called Single RAN. (SRAN). all the equipment and site will have the same LAC since they all will be connected to one core network. Thanks

Sorry yafawi79,

SRAN doesn't necessary means to have same LAC

[dema.89]

Dears; please can i ask a question similar to the posted question

is there is a problem to have same RAC shared between different LAC.
Thanks

[Lazaros]

Hi all,

There could be a drawback with common LAC, due to the fact that due to different paging capacity, there could be a great decrease of the LAC area, if you move from different LAC to common LAC. Eg a city of 4mil people may have in 2G 8 LAC and in 3G 3 LAC. When moving to common LAC, there might be totally 10 LACs, which significantly increases the LAU in 3G network (moving from 3 LAC to 10 LAC). I only see this problem with common LAC

[srilasitha]

Hi

Huawei highlighted following impacts in Co-LAC for 2G & 3G.


The 2G/3G Shared LAC feature has the following impacts on the system:
• When a subscriber roams between the BSC and the RNC in the same location area, location update may not be initiated. Consequently, the current access network type of the subscriber stored in the VLR may be incorrect.
• If the called party is located in the shared LAC, the called party cannot reject the VP call when the MSRN is being allocated.
• The current access network type in the PSI response may be incorrect.
• The paging request is sent over the A interface and the Iu interface at the same time. Consequently, the paging traffic increases.
• The 2G performance measurement which uses the location area as the measurement object cannot be distinguished from the 3G performance measurement.

Does anyone know the impact severity for the following issue and the remedial action.

• If the called party is located in the shared LAC, the called party cannot reject the VP call when the MSRN is being allocated.