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# How to calclate Extra TS on BTS

Viewing 10 posts - 1 through 10 (of 10 total)
• Author
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• #65669
KaKa
Guest

How to calclate Extra TS on BTS such as config all BTS = 12 TRX Extra TS =????

#65670
salah
Guest

I want to know THE RELATION BETWEEN AN ERLAG AND SUBSCIBERS

#65671
ankit limbasiya
Guest

How to calclate Extra TS on BTS such as config all BTS = 12 TRX Extra TS =????

#65672
Bob
Guest

One TrX can provide 8 Channels over Air interface depending on your project some channels are used for signalling and the rest are allocated to TCH. (for signaling 16,32 and 64kbps rate are available)
12 TX as far as I know provide 12*2=24 TCH if 32kbps signaling used then + 1 omu =31 ch
so we have 24 Traffic channels so just put in ErlangB formula with GOS=.01 (For core GOS=.001)
the important matter is how many TCH you have —> use Erlang formula
Hope it comes in use!

#65673
MRG
Guest

Hi salah,
Operators choose Erlangs/Subscriber depending upon clarity. Some choose 25mErl/Subs, some 40mErl/Subs and some go for half rate.
Just divide Erlang by above units.
eg: 1 Erlang/25m Erl=40 subs.

#65674
MRG
Guest

For 2TRUs:8X2=16 Time Slots
BCCH : 1 TS
SDCCH : 1 TS
TCH: 14 TS
Refer to Erlang B table for 14 TS with 0.2GoS=8.2Erlangs
Traffic 8.2 Erl at 2% GoS

#65675
Sebastian
Guest

I got this problem at my Wireless Communications course:

“How many traffic channels may have a BTS with 4 frequencies?”

a. 29 TCH
b. 30 TCH
c. 31 TCH
d. 32 TCH

I would like to know the answer, and also the formula… Any help would be greatly appreciated.

#65676
tuds
Guest

A:32 chls

4 frequency(ARFCN)x8 chls/ARFCN=32

cheers

#65677
pix
Guest

hi sebastian,

well, there are 32 timeslots,
but you need to carry some signalling channels.
So answers A, B, C are possible (those *may* be possible configurations).
Did you have any dimensioning guidelines in your course ?
For 4 TRX, the usual strategy is to put 1 BCCH ts + 2 SDCCH ts, that leaves 29 TCH. That is the best answer. But A, B, C *may* be possible…

#65678
Tanuj
Guest

yes there can be more SD channels depending on the subscribers density and there will also be PD channels

Viewing 10 posts - 1 through 10 (of 10 total)
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