- This topic has 8 replies, 1 voice, and was last updated 11 years ago by Pix.
8th October 2010 at 08:53 #64604OptimizerGuest
can you help me decide this question: number of inner-TRX in the multiband cell – how many it must be, if I use 3TRX (900) in the outer zone? What are criterions for choosing this number?
Thanks, BR8th October 2010 at 11:23 #64605NJGuest
For our case in MBC cell, we configure all TRX 1800 for inner and TRX 900 for complete (trxarea)
nj9th October 2010 at 07:39 #64606pixGuest
it depends on how much traffic will be carried by the inner zone. For 3 TRX outer, you can plan at least 2 inner trx, and up to 4.
The point is to unload the outer zone, because the outer zone frequencies are more difficult to plan. If you remove 1 outer trx, it means one free frequency. By putting 4 inner trx, you might be able to remove 1 outer trx.
I hope I was clear :))
pix11th October 2010 at 06:47 #64607OptimizerGuest
Thanks a lot, guys!
to pix: I take into account traffic, but thought it might be something else, some rules for outer/inner TRX number.
Yup, you were clearly clear), BUT one question. Why “up to 4 inner TRX” (in case of 3 outer TRX)? I don’t see any limiting factor besides traffic.
to NJ: What equipment do you use?
I’ll try realize MBC at Alcatel, so may be you know some specific features for this vendor?
BR, Optimizer11th October 2010 at 19:10 #64608pixGuest
the only limiting factor is the coverage. it is probably useless to put more than 4 inner trx in a cell with 3 outer trx : some inner trx might never get traffic !
Do you know how much traffic is handled by each cell, with only GSM900 TRX ?
pix12th October 2010 at 07:39 #64609OptimizerGuest
A few details. I’ll transform some cells of existing 900/1800 network in MBC – as an experiment. There’re 12 TRX 1800 at one of the sectors, and I’m uptight about congestions at this sector if I’ll use only 3 or 4 TRX instead 12. So I’ve asked about limit of inner TRX.
About 900 TRX traffic for 3-sector cell – appr. 28500 erlang/per month.
Optimizer12th October 2010 at 21:59 #64610pixGuest
yes, you should be ! 🙂
now your question is clear : what is the “software” limit on the number of inner trx 🙂
I thought you wanted the “sensible” limit, according to radio engineering guidelines.
Well, you can create a cell with up to 16 TRX. The number of TRX you could put in the inner zone does not seem to be limited in any way. So, according to the doc (and as far as I’ve read!), you could do this:
4 outer + 12 inner
But really, one cell with 12 trx… it would be better to add some micro BTS’s around, to unload this cell. Your freq planning must be a nightmare !
pix13th October 2010 at 05:56 #64611OptimizerGuest
Yup, that’s what I want to know! I was inarticulate at first post.
I’ll take a message about “nightmare” to our planning department)))
Thanks again 😉
BR, Optimizer13th October 2010 at 15:03 #64612PixGuest
For your planning team, you will become the human representation of “nightmare”. They will fear you like they fear the Devil. They may drop smokin’hot “KFC buckets” in your office to calm your anger…