- This topic has 33 replies, 1 voice, and was last updated 14 years, 8 months ago by ali qaiser.
10th January 2006 at 21:30 #43444patrickGuest
TRX work with RX. Rx div serves only for increasing the sensibility with mobile phone.
if you deconnected rx div, there is no alarm. It is just for a best quality of communication.24th January 2006 at 13:41 #43445TagGuest
If i disconnect Rx main i suppose there will be no alram as well,as i still have the rx div path right?
As for the Rxl path vs the Rxl div path,the system will compare both the signal receive and chose a better rxl level for the uplink?
Am i correct?
Thanks24th January 2006 at 14:27 #43446areebaGuest
if you disconnect the main the TRXs connected to the main will be disabled(VSWR), & the TRXs which regard the disconnected path as div will be operated but with no diversity gain.25th January 2006 at 15:45 #43447patrickGuest
during commissioning, the ultrasite check rx ad div. If it detected both, there is comparison.
If you have only one, ultrasite use it without div.
It is very important to have a good ROSS feeder before to do a commissioning.25th January 2006 at 15:48 #43448PatrickGuest
7604 BTS OPERATION DEGRADED
Rx levels differ too much between main and diversity antennas.
Alarm, you can have if you have a problem on the ROSS feeder.27th January 2006 at 13:52 #43449TagGuest
So if we do not have rx diversity antenna.Can i said there will be no comparsion and no divversity gain?
Pls advice27th January 2006 at 14:07 #43450patrickGuest
Yes, no div, no comparaison.
Utrasite detect RX DIV during commissioning.28th January 2006 at 07:06 #43451areebaGuest
if you havnt diversity ==> no diversity gain.
So no comparison.
And your link palamce will be different ,Cuz you havenot Div gain in Uplink.
so you have to check link palance if it UL limited & no Div ===> you have to decrease DL (BTS power).or insrease UL (Div or TMA)18th February 2006 at 07:38 #43452nassimGuest
this problem can accour when you have difference between the main and diversity RSSI ( TRX level in the same sector)and this difeerence its more then 3db , and the problem in this case maybe in your TRX or feeder or connector so you have to check with site master ( VSWR, and DTF)
DTF should be less than 1.05 in connector and 1.03 in the feeder25th March 2006 at 05:10 #43453ryoGuest
Hi my name is Ryo from Indonesia, I’m new in BTS Nokia Technology,I have alarm 7604 BCF Degraded ‘Rx levels differ to much between main and diversity’ but I already did the sweep test but I think the result is good.I guess the problem comes from the TRX because I can’t do TRX test, it showed ‘RX cabling is faulty or missing’.Is that causing the alarm26th March 2006 at 18:43 #43454R MtnezGuest
In practice, having no diversity (watching statistics of site) won´t affect much the quality of service. in Theory with diversity you gain 3dB ir RX, that means you correlate the 2 paths
saluts.28th March 2006 at 08:41 #43455RAMIGuest
Concerning diversity, there are several types of diversity and all of them to avoid fading. What I mean to say is that the signal transmitted form the mobile is subjected to scattering, reflections, refractions…etc due to the surrounding terrain. These signals may reach the receiver (antenna in our case) either in phase (constructive) which is good or out of phase which is destructive resulting in a zero amplitude signal level (just like to sinusoidal signals shifted by 180 degrees) . So to avoid such phenomena we need to have diversity and in case you have fading on one path the probability to have the same fading on another one is relatively very small. Moreover, you’ll have a gain of 2-3 dBs in the UL direction only.
I hope made it clear…29th March 2006 at 06:53 #43456areebaGuest
#The probability to have such fading through diversity is square the probability of one path.
#Space diversity is good in rural area, & the other polarization diversity is compatible for urban & suburban (because of dense reflection environment)30th March 2006 at 07:05 #43457RAMIGuest
you are right areeba, it is good to hear from you whatever is your name. Maybe we know each other!
Keep in touch21st April 2006 at 01:45 #43458jrGuest
if you look at the site with bts manager you can go to tools and look at the rssl comparison. this shouold point you to what trx or group of trxs are having the issue. Then you can find out if your issue is a cable or even a TMA of MHA