Propagation Delay distance

RAN
1

Hi Experts.

Maybe someone is using Propagation Delay (pmPrachPropagationDelay) new counter for baseband.

I would like to know if anyone can explain what distance corresponds to each Bin.

Vendor Ericsson

2

Elex document has a table on PRACH bin details with values.

3

Only this:

pmPrachPropagationDelay
Propagation delay between UEs and the antenna for a cell, as percentage of the maximum propagation delay within the cell (indicated by the counter pmPrachPropagationDelayMax).

Bins:
[0]: 0 (not used)
[1]: Number of samples less than 1%
[2]: Number of samples less than [1…2[%
…
[10]: Number of samples less than [9…10[%
[11]: Number of samples less than [10-12[%
…
[20]: Number of samples less than [28…30[%
[21]: Number of samples less than [30…33[%
…
[30]: Number of samples less than [57…60[%
[31]: Number of samples less than [60…64[%
…
[40]: Number of samples greater than or equal to 96%

Condition: Measurement is started when the PRACH is setup. Propagation delay is measured on RACH messages with correct CRC. A sample is taken from each detected preamble with successful detected message.
Note that if the propagation delay of a RACH message with correct CRC is negative, bin 1 is incremented, and if the propagation delay of a RACH message with correct CRC is larger than the cell range, bin 40 is incremented.

4

It mentions it is related to cell radius:

Isn’t cell range as per cell radius?

So each sample will be related to cell radius distance.

For one cell cellradius is 2 km for other cell cellradius is 10 km.

So samples will mean different ranges for those 2 cells.

So bin 40 will be for first cell RACH from distance longer than 96% * 2000 m and or second cell RACH from distance longer than 96% * 10000 m.