about rf planning (2 antennas per sector)

[Mr_Piongly]

Hi
Scenario:
You want add more capacity (for istance you need 4 trx) in gsm system for a sector without loose in coverage

A solution:
one solution that I view used for this is the use of 2 antennas and the use of 4 trx with 2 separate combiner , each combiner in low loss mode for each one antenna.

The question:
Why it is not used only 1 antenna with a combiner 4:2 and a booster to compensate the losses for 4:2 configuration combiner (respect a 2:2 configuration) ?

thx

[tthach830]

Hi
Scenario:
You want add more capacity (for istance you need 4 trx) in gsm system for a sector without loose in coverage

A solution:
one solution that I view used for this is the use of 2 antennas and the use of 4 trx with 2 separate combiner , each combiner in low loss mode for each one antenna.

The question:
Why it is not used only 1 antenna with a combiner 4:2 and a booster to compensate the losses for 4:2 configuration combiner (respect a 2:2 configuration) ?

thx


You will boosting the noise too. Your RSSI might be good;however, your noise (SNR) would be very bad.

[s52d]

Hi
Scenario:
You want add more capacity (for istance you need 4 trx) in gsm system for a sector without loose in coverage

A solution:
one solution that I view used for this is the use of 2 antennas and the use of 4 trx with 2 separate combiner , each combiner in low loss mode for each one antenna.

The question:
Why it is not used only 1 antenna with a combiner 4:2 and a booster to compensate the losses for 4:2 configuration combiner (respect a 2:2 configuration) ?

thx

That is what we do. up to six TRXes on one antenna, using filter combiners.
Up to 12 TRXes on two antennas. 3 dB combiner loss.
Of course, BB hopping is used instead of synthesizer hopping.
TRXes usually provide enough power to compensate for combiner loss.

Busters are not needed: we need to hear terminals. (Link balance).
It is common mistake of new operators to use full power with no combiners
to provide false coverage. Terminals camp on the BCCH, but they can not answer calls
because they are lost in the noise on the base station RX chain.

BR
s52d

[sabila]

in my network we used antena with 4 port feeder(in this case we use argus)
so we can use 1 antena for 8 trx :p