1 Calculation method of UL-DL balance in existing Network
PB=actual DL level average—actual UL level average
1. Combiner Level 1 is adopted in judgment criteria. If other combining methods but
Combiner Level 1 are adopted in the existing network, like no adoption of combiner or
two-levels of combiner, combiner difference shall be compensated to fulfill the
judgment conditions stipulated in the criteria;
2. If TA is installed, it’s interference must be eliminated to meet judgment conditions;
If no TA is installed in the antenna system, there is no need to consider
about its influence;
Influence of external TA on antenna system shall be taken into
consideration. TA falls into two types: one-way TA (UL, usually referred
as TMA) and two-way TA (UL-DL, usually referred as Booster). If it’s two-
way TA, the influence on UL and DL will be cancelled out. If it’s one-way
TA, influence on UL and DL shall be considered respectively;
3. If coverage enhancement technique is adopted, the gain produced by it shall be
eliminated.
1.1 Method for calculating ZTE UL-DL level average
Create cell radio measurement. Gather statistics per day. See Table 3-1 for
counters:
Table 1-1 Cell radio measurement
Counter name BTS_V2 BTS_V3
Total value of uplink signal strength of wireless channels
C10710 C901120010
Number of received uplink signal strength samples of wireless channels
C10707 C901120007
Total value of downlink signal strength of wireless channels
C10714 C901120014
Number of received downlink signal strength samples of wireless channels
C10711 C901120011
UL level statistical average
C10710/ C10707
C901120010/ C901120007
DL level statistical average
C10714/ C10711
C901120014/ C901120011
1.2 Correction of UL-DL level average
influence from dynamic power control
In ZTE the cell measurement is as for MS UL signal receive level in 900M cell, its
value in calculation is 10dB larger than its real value, because of the influence from
dynamic power control. Therefore, in statistics, the value of MS UL signal receive level
shall be reduced by 10dB accordingly.
influence from UL channel gain
In BTS V2_TRM calculation formula, there is a difference of 14dB between the UL
level statistical value and that of DTRU/ETRM. This is because the UL channel
receive gain on TRM module is 14dB higher than that of the following ETRM/DTRU
modules, the 14dB shall be deducted in PB calculation.
See Table 3-2 for UL-DL level real average
Table 1-2 UL-DL level real average
UL-DL
Frequency band
Product series
BTS V3(dB)/ BTS V2_ETRM(dB)
BTS V2_TRM(dB)
UL 900M
UL level real average = UL level statistical average -10
UL level real average = UL level statistical average -10-14
DL DL level real average =DL level statistical average
UL 1800M
UL level real average = UL level statistical average
UL level real average = UL level statistical average -14
DL DL level real average =DL level statistical average
1.3 Calculation method of UL-DL balance
In calculation of UL-DL balance of existing network, information in Tale 3-3 needs
to be obtained.
Table 1-3 Influencing factors in UL-DL balance calculation
Influencing factors Explanations
Frequency band of existing network
There is a difference of 3dB in judgment criteria due to different frequency bands;
Model of BTS products used & modulation method adopted
Because the BtsTxPwrMax is different, judgment criteria for different BTS products are different;
Combining method adopted
Combiner level 1 is adopted in the judgment criteria. CduLoss difference caused by other combining methods shall be eliminated.
If external TA installed? In the judgment criteria, default is NO TA; if external TA is installed, its influence on UL-DL shall be eliminated.
If coverage enhancement technique adopted?
The gain produced by coverage enhancement technique shall also be eliminated.
See Table 1-4 Calculation method of UL-DL balance.
Table 1-4 Calculation method of UL-DL balance
Frequency band
Product series
BTS V3(dB)/ BTS V2_ETRM(dB)
BTS V2_TRM(dB)
900M DL level statistical average-(UL level statistical average -10)
DL level statistical average-(UL level statistical average -10-14)
1800M DL level statistical average-UL level statistical average
DL level statistical average-(UL level statistical average -14)
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