PRACH Propagation Delay

[Rodbar]

Could anyone tell me how can I extract the information regarding PRACH propagation delay from Huawei RNC?

I used to analyse this KPI to look for overshooting cells in Nokia-Siemens RNC, but I don't know how to extract the same information from Huawei RNC.

Thanks in advance!

Rodrigo Barreto

[adewijaya]

using NASTAR (Statistic tools from Huawei)

[Rodbar]

Unfortunately we don't have access to Nastar Tool.

Do you know another way to get this KPI from Huawei RNC?

Thanks!

Rodrigo Barreto

[adewijaya]

Nope, from M2000 i didn't got this. Only with NASTAR

[qaqa]

hi man

the only way to get if not having the CHR analyzer is by doing the IOS tracing for the cell. you will get the propagation delay after the PRACH is sent. you will need to filter out this information and do some magic calculations to estimate you PD.
later on I will post a detailed way to do it :-)

[adewijaya]

already done yet or not my frend?

[Rodbar]

Sorry, but I have no idea of how it could be done. Could you explain it for me?

Thank you very much!

[adewijaya]

hi man

the only way to get if not having the CHR analyzer is by doing the IOS tracing for the cell. you will get the propagation delay after the PRACH is sent. you will need to filter out this information and do some magic calculations to estimate you PD.
later on I will post a detailed way to do it :-)

@qaqa, do you have some update about this request? :)

[qaqa]

Hi guys
as promissed, attached is a snapshot of an IOS tracing for RAN12. If you look at it you will see a proper message called:" Propagation delay". going to message details window you see ucRachPropagDelay message.to compute your mobile_Distance use this formula:

Mobile_Distance (m)=(ucRachPropagDelay+1.5)*3*78

ucRachPropagDelay= you extract from the message.
3= is the measurement resolution (3 chips)
1.5= is a correction parameter for HW system. in 3GPP (25.435) the formula doesn't include this value.
78 (m)= is the Chip distance.

in this case, the mobile is about (4+1.5)*3*78=1287m :p

Cheers,

[vasili_koslov]

Hi gaga,

thanks for shared. I wanna ask some questions.Please Could u explain "measurement resolution" and " chip distance"? And How I get them,Where?



Hi guys
as promissed, attached is a snapshot of an IOS tracing for RAN12. If you look at it you will see a proper message called:" Propagation delay". going to message details window you see ucRachPropagDelay message.to compute your mobile_Distance use this formula:

Mobile_Distance (m)=(ucRachPropagDelay+1.5)*3*78

ucRachPropagDelay= you extract from the message.
3= is the measurement resolution (3 chips)
1.5= is a correction parameter for HW system. in 3GPP (25.435) the formula doesn't include this value.
78 (m)= is the Chip distance.

in this case, the mobile is about (4+1.5)*3*78=1287m :p

Cheers,

[zlobster]

Hi guys
as promissed, attached is a snapshot of an IOS tracing for RAN12. If you look at it you will see a proper message called:" Propagation delay". going to message details window you see ucRachPropagDelay message.to compute your mobile_Distance use this formula:

Mobile_Distance (m)=(ucRachPropagDelay+1.5)*3*78

ucRachPropagDelay= you extract from the message.
3= is the measurement resolution (3 chips)
1.5= is a correction parameter for HW system. in 3GPP (25.435) the formula doesn't include this value.
78 (m)= is the Chip distance.

in this case, the mobile is about (4+1.5)*3*78=1287m :p

Cheers,

Hi qaqa,

I personally couldn't find the formula about RACH propagation delay. Could you please include the subclause of the 3GPP TS where you found it?

Anyway, I think there's an error in the formula you propose. :eek:
I think (4+1.5)*3*78=1287m should be as a sum instead of multiplier, i.e. (4+(-)3+1.5)*78= somewhere from 195 to 663. That's because 3 IS the granularity of the measurements. This means that you cannot distinguish measurements within 3 consecutive chips.

That's just IMHO, though.

6.2.7.5 Propagation Delay [FDD]
Description: One-way radio interface delay as measured during RACH access.
Value range: {0 .. 765 chips}.
Granularity: 3 chips.
Field length: 8 bits.

^taken from 3GPP TS 25.435

'ай със здраве (regards),;P

[qaqa]

Hi there,

for the formula I provided I did a mistake. the formula should be:

Distance=(PD*3+1.5)*78

@ Zlobster
the section from 3GPP is the same you provided.

For distance calculation formula, The 3 Chips granularity is your sampling for the PD estimation therefore the total number will be PD*Granularity

@ Others
Chip distance is the wavelength, you can calculate it using the formula: [Light_Speed (=3x10^8m/s)]/[Chip_rate(=3.86 Mcps)] =77.72m

thanks

[hesh]

Could anyone tell me how can I extract the information regarding PRACH propagation delay from Huawei RNC?

I used to analyse this KPI to look for overshooting cells in Nokia-Siemens RNC, but I don't know how to extract the same information from Huawei RNC.

Thanks in advance!

Rodrigo Barreto

Hi,

Take IOS data, if You are unable to find IOS data by yourself then ask OMC guys to put IOS trace on any given cell, and take the output of trace and do as mentioned in my doc.

hope this will make your life easy..

[topoffenders]

Hi There;

is the Counter for PD is also available on CHR (cell trace?)

Thanks