- This topic has 14 replies, 1 voice, and was last updated 6 years, 7 months ago by
pix.
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RF engr
GuestPlease throw some light on RF Link Balnce. Wat is this and wat should be the values for good link balance
dizz
GuestTo have a good link balance i.e. Uplink = downlink pathloss.
RF Engr
GuestPlease elaborate your answer and also tell me the difference between Link Balance and Path Balance
nall
GuestPath balance = (UL loses – DL loses)+100
*addition of the 100 is make the overall figure a positive value in stat. Plz correct me if I’m wrong!
further there is set parameter value which defines the stability of the overaall system.
RF Engr
GuestI think we add 110 in UL-DL value.
Also explain in detail what should be the mean value of this and the standard deviationt28
Guesthi guys,
there is nothing the same between path balance and link balance.
RF link balance=DL level-UL level.
superb value (900 DRX)is 2.5, or 12.5 in case of LNA, on 1800 DRXs good value is about 4 – 5.BlessCurlz
GuestPath Balance:
The method used analyzes downlink vs. uplink path balanced path and reliability (based upon lognormal fading). The contour limit becomes the received signal level set to balanced path conditions with the appropriate reliability. It is dependent upon a number of factors, including: tower height,power,combiner, and receive sensitivity.John
GuestPath balance = (ul losses – dl losses) + 105
where 105 is the optimum value for the path balance
in case of -ve path balance this means the dl losses is greater which means a tx calibration for the bts is needed (adjust tx power)
and in case of +ver path balance this means the ul losses is greater which means a rx calibration is needed to adjust the sensitivity of the rx of the bts
nall
Guestplease advise on a project to carry to test the Parameter settings of Motorola BTS n Ericsson BTS !
Pix
GuestJohn,
maybe we don’t calculate the path bal in the same way. “my” path balance is centered around 0..
path balance < 0 means losses in the UL (poor UL RX) path balance > 0 means losses in the DL (weak DL TX)
path bal = (Pow(TRE TX) – RXLEV(DL)) – (Pow(MS TX) – RXLEV(UL))
Mohan
GuestGood article for Huawei path balance.
hubpages.com/hub/Path-Balance-in-Huawei
Eng
GuestHi guys 🙂
Understood, that if your unbalance value close to ZERO then it is OK.
But what is permissible value of unbalance between UL&DL?
From which value will strong problem with KPIs begin?Please, share. Thank you)
pix
Guesteng,
typically, path balance should be between -5dB and +5/+8dB
but when the PB is outside these values, sometimes you won’t see a problem. KPI remain fine because the neighbours will handle areas where the loss of coverage happens.
Typically, in urban areas, the overlap with the neighbours is good enough -> a site with bad PB will still have good KPI.
But you will notice that the neighbours are handling traffic which is outside their “comfort” zone, and that they are having some KPI issues (sometimes).Regards
pixjalloul
GuestWhat about Power Control when calculated Path Balance ?
pix
Guestthe attenuations caused by power control should not be taken into account in the calcul, for best restuls.
In ALU, they are removed from the computations.
In E/, they are not, so one must either disable the PC during the MRR recording, or take into account the MS Pwr and BS Pwr graphs when looking at the Path Balance graph.
Cheers,
pix -
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