BCCH in OL Subcell Implementation

[ejamhas]

Hi,

Anyone with experience of BCCH in OL subcell implementation. Kindly reply.

Thanks :)

[zeldalcl]

i think u should use the TIGHT BCCH REUSE feature, that bettervthan bcch in ol subcell

[Darko]

Don't do that man...

As zeldalcl recommended, you can use TIGHTBCCH to transfer distant users to other CHGRs. Also, there are other possibilities of traffic distribution (LOL, SCLD...), if that's what you need.

[ejamhas]

Thanks zeldalcl and Darko. Actually the reason of going to BCCH on OL subcell is that we have limited band on GSM900 but on the other hand have plenty of GSM1800 frequencies. In the city we have high interferene on GSM 900 on both BCCH and TCH. So I was thinking where the inter-site distance is less than 1Km we can go for BCCH in OL Subcell to cop up with this issue. What do u think? Please advice!

Thanks :)

[Darko]

Have you tried to modify MBC parameters with current configuration and make more aggressive traffic distribution from UL to OL, and also set higher threshold for tightbcch (to free BCCH freq.)?
These actions should produce significant improvements.

I have seen only one case of OL BCCH until now and that was a trial test which didn't bring expected results, but that was a network without interference issues.

If you decide to go with OL BCCH share the results with us. It would be interesting to see how it is performing in your network.

D.

[ejamhas]

Hi Darko,

Thank a lot for your quick reply. Yeah I have increased LOL only as I am not allowed to change SCLD settings and SCLD is currently OFF. Also I have no idea about tightbcch. Is it some feature something. Can you please explain it a little.

Do u have any data on that trial test of OL BCCH. Like some report or something. Also I am interested in the configuration of cell with BCCH in OL. If you have anything related to it plz share.

Thanks again

Cheer :)


Have you tried to modify MBC parameters with current configuration and make more aggressive traffic distribution from UL to OL, and also set higher threshold for tightbcch (to free BCCH freq.)?
These actions should produce significant improvements.

I have seen only one case of OL BCCH until now and that was a trial test which didn't bring expected results, but that was a network without interference issues.

If you decide to go with OL BCCH share the results with us. It would be interesting to see how it is performing in your network.

D.

[ejamhas]

One more thing. I have initiated FAS on a cell with high TCH drops due to BQ. According to the FAS results my concerned cell has around 48% Co-channel interfered traffic in UL with its immediate nbr . On checking that cell causing co-channel interference I found nothing. There is no BCCH, HSN or MAIO clash. Also we have 1x1 on UL (GSM900).

Please tell me what is wrong here... am I missing something?

Thanks

[zeldalcl]

Dear Ejamhas!
I recommended use Tight BCCH reuse instead of BCCH in OL subcell so that had a best result. I had trialed Tight BCCH reused then the result, Drop by quality improved 30% than affter. So u can use Tight BCCH reused with change FBALLOCATION then it great. If u used OL/UL instead of Tight BCCH so u meet some problem about congestion.

Brs

[ejamhas]

Hi zeldalcl,

Thanks alot for the valuable advice. Well I am not sure what do you mean by Tight BCCH reuse. Is it some feature or some optimization technique. Can you please tell me the exact parameters and their recommended values.

Thank you very much :)



Dear Ejamhas!
I recommended use Tight BCCH reuse instead of BCCH in OL subcell so that had a best result. I had trialed Tight BCCH reused then the result, Drop by quality improved 30% than affter. So u can use Tight BCCH reused with change FBALLOCATION then it great. If u used OL/UL instead of Tight BCCH so u meet some problem about congestion.

Brs

[zeldalcl]

Dear Man!
The Tight BCCH Reuse is a Feature in E******* System.
Capabilitie:
The aim of this feature is to reduce the number of frequencies used for non-hopping BCCH carriers, i.e. tighten the BCCH frequency plan by limiting the speech traffic usage of the BCCH carrier to the area close to the sites and to the peak traffic periods. Tighter BCCH frequency reuse is possible regardless of if subcells are used or not. If subcells are used, the BCCH may be placed in either the Overlaid or the Underlaid subcell. This feature is only applicable for a non hopping BCCH. This feature is a next generation of BCCH in Overlaisubcell.

By only allowing mobiles with low path loss and low interference to the BCCH carrier leads to less interfered traffic on the BCCH frequency and the BCCH frequencies can be tighter planned and improve Uplink Quality. The BCCH CHGR is not suitable if a mobile is located between the BCCH GHGR border and the cell border.

BRs!

[ejamhas]

Hi zeldalcl,

Thank you so much. Do you have the UD for this feature. If you have can you please share it.

I really appreciate your help. :handshake



Dear Man!
The Tight BCCH Reuse is a Feature in E******* System.
Capabilitie:
The aim of this feature is to reduce the number of frequencies used for non-hopping BCCH carriers, i.e. tighten the BCCH frequency plan by limiting the speech traffic usage of the BCCH carrier to the area close to the sites and to the peak traffic periods. Tighter BCCH frequency reuse is possible regardless of if subcells are used or not. If subcells are used, the BCCH may be placed in either the Overlaid or the Underlaid subcell. This feature is only applicable for a non hopping BCCH. This feature is a next generation of BCCH in Overlaisubcell.

By only allowing mobiles with low path loss and low interference to the BCCH carrier leads to less interfered traffic on the BCCH frequency and the BCCH frequencies can be tighter planned and improve Uplink Quality. The BCCH CHGR is not suitable if a mobile is located between the BCCH GHGR border and the cell border.

BRs!

[zeldalcl]

Hi guy!
The Tight BCCH Frequency Reuse is a FAJ 121 813 in Feature catalog. U can active feature in BSC and then modifie some parameters to receive best result.

Brs!