- This topic has 5 replies, 1 voice, and was last updated 11 years, 8 months ago by David.
12th August 2009 at 07:04 #58403DavidGuest
Our network deals with the OU/UL concept. Band used are 900 and 1800. I wanna know y is it not allowed to allocate EDGE TS in 1800 band. my vendor says its too risky to allocate in this way. Is there anyone to help me in this so that i can increase the TS for EDGE.17th August 2009 at 09:54 #58404DavidGuest
No one to answer my query?
Pix? Any idea?17th August 2009 at 18:18 #58405PixGuest
Unfortunately the resources allocation are very vendor dependent… I’m not sure I can help you, but I can describe the main concepts used in Alcatel.
In case of multiband network, the GSM900 is supposed to provide all the GPRS capacity, while the DCS1800 cells just have one PDCH statically defined. The point o this PDCH is that a user camping on DCS1800 (they have bigger C2) will always have a PDCH available. As soon as the TBF is allocated, the user is sent to the GSM900 cell (it is a special feature of the NC2 reselection, called “redirection”)
Now, you want to allocate some more PDCH in the DCS1800. Unfortunately, these are also the cells that carry most of the voice capacity. Basically, you are trying to squeeze both voice and packet within the same cells (ie. the DCS1800). It is risky : the voice being always the favourite, the packet service will be heavily impacted !
A better strategy is too unload as much as you can the voice in the GSM900. Make as room as possible for the PDCHs.
Then activate NC2 and push packet traffic onto the GSM900.
Now, it’s up to you to implement this strategy, I can’t help regarding which parameter you should change to do that.
“redirection” can be achieved by setting a very quick and easy detection of NC2 reselection from DCS1800 to GSM900 only.
pix18th August 2009 at 10:19 #58406DavidGuest
A simple optimization willnt’ solve the purpose? I will reduce my present 1800 Antenna Tilt making the radius larger. This can share the CS traffic of 900 right? am gonna allocate PDCH in 900 alone. CS traffic in my 900 is gonna reduce hence maintaining my kpi.
I doubt it would be right n if so thanks for igniting my brain :).18th August 2009 at 12:09 #58407PixGuest
I’m not sure I understand what you wan to do…
Increasing the radius size of the DCS1800 is possible, but keep in mind the 1800MHz propagation is much weaker than 900MHz.
But okay, anyway, normally the DCS1800 should have less downtilt than GSM900, so that both coverage are approximatively matching.
Once you achieve this, the only way to balance traffic is to do “not simple” optimization 🙂
pix19th August 2009 at 09:52 #58408DavidGuest
Hey i didnt mean to match both 900 and 1800 by optimizing. i can reduce the tilt at least a bit more so that we can balance the traffic that is goin in 900. Hence, i can reduce the utilization in 900, so that the dynamic pdch that i allocate in 900 shall be effectively utilized without effecting traffic.
Something Wild? Thanks in advance.