- This topic has 22 replies, 1 voice, and was last updated 2 years, 11 months ago by Chanmyae.
16th April 2008 at 16:00 #51869scorGuest
How many subscribers can successful call establishments in one TRX
Thks17th April 2008 at 08:37 #51870PixGuest
Call establishments :
8 call setup procedures per timeslot SDCCH
1 active call per timeslot TCH in full rate
2 active calls per timeslot TCH in half rate
in one TRX, you have 8 timeslots, so it just depends on your configuration.
however, the number of calls is not an information we use, we rather use erlang values (based on erlang B law)17th April 2008 at 13:33 #51871scorGuest
For 2+2+2 config
16*3=48 Active calls(Full Rate Erlang). Am I Right
What about the signalling part timeslots?
Thks17th April 2008 at 14:03 #51872pixGuest
1 sector 2 TRX = 2*8 timeslots = 1 BCCH + 1 SDCCH + 14 TCH
–> 14 simultaneous calls + 8 simultaneous call setups
2+2+2 –> 42 simultaneous calls + 24 simulatenous call setups.
“1 call setup” is a procedure to seize a TCH, it lasts about 4 seconds.7th June 2010 at 05:50 #51873Manoj GuptaGuest
How many calls can do from one BTS of Conf. 4 4 4 in full rate capacity8th June 2010 at 04:24 #51874PrabeenGuest
A maximum of 2160 FR calls shall be made. That is 2160/3 = 720 calls per cell. But remember this is just theorotical calculation giving an average of 25merl to a subscriber.12th June 2010 at 07:34 #51875kalimGuest
max no of callers, if
4+4+4(using 8 users)=96 users at H.R
4+4+4(using 7 users)=84 users at H.R
4+4+4(using 8 users)=192users at F.R
4+4+4(using 7 users)=168 users at F.R13th June 2010 at 08:05 #51876RafiGuest
It looks you have interchanged FR and HR. FR is always less than HR. HR is less than or equal to 50% of FR.14th June 2010 at 07:39 #51877machzarGuest
hi Prabeen, Pix and all, would you explain to me more why you can get theoritical 2160FR
because from my calculation for 4/4/4 in FR,
I just have only 90 simulatenuos call and only 24 call setup.
it comes from :
1 sector 4 Trx = 4*8 TS = 32 TS
= BCCH + SDCCH + 30TCH
4/4/4 –> 96 call + 24 call setup.
thx before.14th June 2010 at 09:50 #51878pixGuest
the call setup is done on SDCCH and then released.
One call setup lasts only 3 seconds. So the 24 channels are used repeatedly until the 90 TCH are used.
In a restaurant, there are only 2 waiters for 30 tables. The 2 waiters are serving every table once in a while.
The SDCCH is doing the same : it is serving every TCH once in a while (to locate a MS on it).
I hope the analogy works..
(no, no need to tip the SDCCH at the call release)
pix19th June 2010 at 09:38 #51879Sineesh CGuest
Please Explain the Amazing Technology of supporting 2160(FR)simultaneous User in one BTS.
What is the meaning value 25merl that you given user ?.21st June 2010 at 06:24 #51880PrabeenGuest
Its not simultaneous calls. Its capacity of a 4+4+4 cell taking 25merl per sub.
25merl: This is the average erlang that shall be utilized by a subscriber. This value is used for all theorotical calculation for capacity issues.
Calculation: 4TRX supports a maximum of 18.4erl. 18.4/.025 = 736 subscribers. The same for all the 3 sectors gives you around 2200 subscribers. BUT NOT SIMULTANEOUS.24th June 2010 at 06:04 #51881AmexGuest
Could you plz help me!!!
Can i put 2RBS per sector (Ericsson 2206, band 900)? Is it posible to synchronize them?
Present logical configuration is 3,3,3 (XRANGE and TCC activated) phisical is 12,12,12 i want to increse it to 4,4,4 means Phizical 24,24,24
Amex24th June 2010 at 12:52 #51882PrabeenGuest
It depends on number of arfcn u have. How many arfcn do u have?25th June 2010 at 04:29 #51883AmexGuest
Hi Prabeen. thx for you answer.
we are using hoping and 18 arfcn on them. what can i do? this site serving huge coverage