Recommendation about layer of G900 and G1800 Vendor E*******

[TEMS]

Dear everybody
did someone know about layer of G900 and G1800 of Vendor E*******, which one layer that we put on G900 and G1800?
Can we put both of them to only layer 1, and also if we put G1800 to Layer 1 the same G900 it will be got low traffics, did somebody know which one parameter that can push traffics form G900 to G1800

thanks to all member for kindly help

[tremalnike]

Hi friend,i just want to share my point of view. I prefer to use same layer for 900&1800 cells, because it's easy to tune and suitable for dynamic networks(in my thinking, i don't have enough experience with HCS).There are easy ways to balance traffic between 900&1800 cells in same layer. This is essential settings that you need to do that. In most cases this is enough to balance traffic:

Idle mode behavior:
Add positive cell reselection offset to 1800 cells : CRO (6 to 10dB is a good value for initial tuning)- This will allow 1800 cell to capture MS's , when 900 cell has better signal strength.

Locating (in case of E/// 3 algorithm):
Add positive Offset to 1800 -> 900 neighbors relation:OFFSETP ( 6 to 10 dB for initial) - Use this to increase 1800 cell nominal cell border.
Add negative Offset to 900 ->1800 neighbors relation: OFFSETN ( 6 to 10 dB also for initial) - Use this to help unloading 900 traffic to 1800 cell.
It's good idea to set OFFSET with a bit higher value than CRO, in order to avoid ping-pong (Re-selection to 1800 > Call set up in 1800 cell > HO to 900 cell > again cell re-selection to 1800 after call end). Note that OFFSET parameter is non-symmetric, and need to be set separately for any neighbor direction.
Of course , when 900&1800 cells are in same site using OL/UL Subcell structure is mandatory.

I hope this will be useful for you. Any finetopix buddy who can share practical experience with Hierarchical Cells Structures will help too.

[TEMS]

Daer all

Thanks My friend tremalnike, anybody have any update on this recommendation please kindly share practical experience with Hierarchical Cells Structures also.

[Ericsson_RND]

From my experience it depend on interference affect, usually upgrade N/W with dual band either for capacity subject or to reduce the external interference on GSM900

Accordingly you can put different layer for both bands and control layerthresold parameter.

In our N/W we set layer 7 for GSM900 and layer 4 for GSM1800 also layerthres 95 for GSM900 & 75 for GSM1800 and every thing is fine.
based on N/W KPIs monitoring you can control parameters.

[alert181]

I concur with tremalnike.

It's best to put them on the same layer, but on different HCS bands.

Depending on which band has more frequencies, you can set a higher HCSBANDTHR to balance the traffic between the bands.

You can also use the LAYERTHR parameter to push traffic to one layer/band. A higher LAYERTHR encourages more traffic.

Hope this helps.