Can we use Low band LTEs as an anchor layer towards Mid band 5G

5G NR
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1

Hi there,
We have used low bands (L7 & L9) as an anchor layer towards Mid band 5G NSA (3500 Mhz TDD) along with the existing LTE mid band anchors (L18/L21). The 5G RACH success rate is quite bad hovering around 30% where most of the failures are happening in “pmRadioRaCbFailMsg3Dtx” (Number of RACH attempts failed due to DTX detected).
The RACH preamble format for 5G is B4 and the equipment is Ericsson.

2

Use preamble format 0 to increase the cell range. There is a feature for that

3

Preamble format 0 for Mid band 5G (3500 Mhz) with TDD_UL_DL configuration set to 2 is not recommended in Ericsson. Current settings we have for 5G:

ZeroCorrelationzone: 0
Ncs =0
Preambles=16; reuse at every 9th cell.
Max cell range~ 5km

4

play with your cbrapreamble rsrp and b1 threshold

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