My policy: assign HR to a call in last free TS.
This makes decent balance between HR/FR ratio on one side, and TCH congestion on another side.
As E/// needs to specify "number of free TS" in %, you ned different settings for each
cell, based on number of TRXes.
Bonus fun: when number of TRXes is changed, you have to change this parameters.
On top of it, you decide if TS used by GPRS/EDGE are considered free or busy for
this calculation. (do you want more FR or more EDGE?
Also, you might use different quality target for HR-AMR/HR, based on better robustness of AMR.
This one I do not bielive: works fine in gaussian noise, when random bits are wrongly
detected, but does not work if whole burst is lost. Observe FER and SQI stats.
How to calculate Half/Full rate parameters for each cell ?
I want to calculate globally for all of cells of a BSC.
(E******* 2G vendor)
Thanks
Hi guy,
In my opinion, u should calculate HR/FR as following :
1, Based on TU (Traffic Utilization)
TU = Traffic Peak Hour / Traffic Offer
where : Traffic Peak Hour is traffic of one cell at peak hour, U can extract it from OSS (counter). And Traffic Offer is calculated as guideline of Aircom, I think you know "GSM Applied Cell Planning" of Aircom, right ? .
2, You should maintain 85% < TU(with HR) < 95% and TU( without HR) < 120%.
3, If 80% < TU (with HR) <85% (in 4 days of 7 days), you should decrease %HR.
If 95% < TU (with HR) < 120% (in 4 days of 7 days), you should increase %HR.
If TU(with HR) < 80% (in 4 days of 7 days), you delete HR.
If TU(with HR) > 120% (in 4 days of 7 days), you should add more radio resource (TRx, new cell, new site....)
General conditions of HR
According to your requirements.
1. DIrect allaoction of HR to a cell .... Not required as it is unnecessary
2. HR should be riggered only when the cell reaches certain % congestion /loading Keep according to your requirement observe the changes then change
3. HR triggering is also based on level. Check the C/I , Qualityand channel type using drive test.
4. And Codec threshold for AMR HR C/I value may be changed according to your requirement based on drive and statistics (codec mode penetration)
5. If u are employing concentric cells, better to avoid HR in innerband.
HR can be implied upto a certain percenatge of congestion. Better u can try directed retry and other options also.
ANy comments welcome.
Last edited by radio_network; 2010-10-17 at 09:38 PM
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