- This topic has 13 replies, 1 voice, and was last updated 15 years, 8 months ago by
TNS.
-
AuthorPosts
-
7th January 2008 at 11:18 #50331
rala
GuestCould someone tell me..
For Alcatel equipment,
we would like to build up the sector configuration more than 2 TRX.
Have someone ever use the ANC and ANY with HPTRE(high power TRX)instead of use the double antenna and the ANC with MPTRE(Medium power)? How much the coverage effect? Thank you very much.7th January 2008 at 16:18 #50332pix
GuestRala,
“double antenna”, you mean two outputs ? Because the two ouputs can be connected to only one crosspolar antenna.
So 4 TRX into 1 ANC = 2 outputs = 1 Crosspolar antenna
Instead, you want to plug 4 TRXs in order to have only 1 output ?
You’ll have to use 1 ANy and 1 ANC
4 TRXs –> ANy –> ANC
Possible, but you will not have RX DIVERSITY (obviously)
Total loss : 7.9 dBThe other choice : just 1 ANC with 2 outputs, it gives you only 4.6dB loss.
Delta loss is 3.3dB.
The delta power between MP TRX and HP TRX is +1.3dB in GSM900 and +2.4dB in DCS1800.
Therefore, in GSM900, by using a single output configuration with HP, compared to double output configuration with MP, you loose 2dB. In rural area, this is lead to an important loss of coverage.
In urban area, the difference in coverage is hardly visible in outdoor, but can have a big impact for indoor subscribers.Regards,
Pix8th January 2008 at 03:55 #50333rala
GuestDear Pix,
Thank you very much for your reply! I have to corrected my question that accually we would like to config to be more than 4 TRX in one sector(not 2 TRX) and we use the DCS1800.
In normal way we used 4 MP TRX –>ANC –>double ant.(2 crosspolar antennas) And we would like to consider to use the 4 HP TRX –>ANy –>ANC –>1 crosspolar anttenna as we ask for the coverage effect.
Regards,8th January 2008 at 05:04 #50334Pix
Guest1 ANC goes into 1 cross polar antenna, not two !!!
4 TRX :
4 TRX > 1 ANC > 2 outputs > 1 Xpol6 TRX :
4 TRX > 1 ANy—
)–> 1 ANC > 1 Xpol
2 TRX———–8 TRX :
4 TRX > 1 ANy—
)–> 1 ANC > 1 Xpol
4 TRX > 1 ANy—All other info to compute loss delta between the two config are provided in the previous post.
Regards,
Pix8th January 2008 at 06:05 #50335rala
GuestDear Pix,
Thank you to make it clear. : )
Regards,10th January 2008 at 17:42 #50336TNS
GuestHi, Pix.
I didn’t understood what Rala wants to do…
4 MP DCS TRXs + 4 HP DCS TRXs in the same sector to obtain 8 TRX capacity and minimum coverage losses?BR,
TNS10th January 2008 at 21:11 #50337pix
GuestTNS,
I have no idea 🙂 Sometimes it is harder to ask good question rather than to give good answers…
The sure thing is that mixing HP TRX and MP TRX in one sector is stupid…
11th January 2008 at 05:33 #50338rala
GuestDear all,
Sorry that my first question is not so clear.
Accually I want to do the 5 MP TRX sector but I have only one crosspolar antenna.
So I brought the ANY to use with ANC.(To aviod to add more antenna) Of cause the loss is more. Then I used the HP TRX intead of MP TRX.
1. If we have 2 Antennas.
ANTa –> ANCa(4 port) –> 4 MP TRX
ANTb –> ANCb(1 port) –> 1 MP TRX2. If we have 1 Antenna.
ANTa –> ANCa(2 port) –> 2 MP TRX
ANTa –> ANCa(2 port) –> ANY –> 3 HP TRXBut I’m not sure about the coverage result.
That Pix kindly answered to me. : )11th January 2008 at 10:09 #50339Pix
GuestRala,
Ok, in this situation, your solution is good : the HP TRX will compensate for the loss of the ANY, so altogether :there is only a loss of 0.9dB between old configuration (only MP TRX + ANC) and the new config (MP + ANC and HP + ANY + ANC)
not bad 🙂
11th January 2008 at 17:25 #50340TNS
GuestHi, all.
In this case:
“…
2. If we have 1 Antenna.
ANTa –> ANCa(2 port) –> 2 MP TRX
ANTa –> ANCa(2 port) –> ANY –> 3 HP TRX
…”,the SUMA should automaticaly equalize the output power to the module with lower power ( MP ).
So to use mix MP+HP TRXs there is no sense…Isn’t it?
BR,
TNS
11th January 2008 at 21:52 #50341pix
Guesthi,
compensation is done thanks to BTS output values. it takes into account the power of the TRX – losses from combiners, connectors, etc..
14th January 2008 at 19:37 #50342TNS
GuestHi, Pix.
I’m sorry but I didn’t get this…
What is “BTS output value”?BR,
TNS14th January 2008 at 21:36 #50343pix
Guestfor example, in one cell (the values are approx !) :
a HP TRE is connected to ANC = 48 – 4 = 44dBm at BTS antenna connector (= BTS output)
a MP TRE is connected to ANY + ANC = 46 – 4 – 3 = 39dBm at BTS antenna connectorThe HP TRE will be decreased by 44 – 39 = 5dB, so the actual TX POWER of this TRE is 43dBm.
The attenuation is not “48 – 46” = 2dB.
16th January 2008 at 19:48 #50344TNS
GuestHi, Pix.
I got the point.
Thank you.BR,
TNS -
AuthorPosts
- The forum ‘Telecom Design’ is closed to new topics and replies.