Hi All,

I am struggling to interpret a table of 5G prach, page 48  

https://www.etsi.org/deliver/etsi_ts/138200_138299...

For example format A1 has three entries for preamble length(139, 571, 1151) , 

If mu is 2 or 3 then only 139 is implied. No problem

but if mu is 0  then either 139 or 1151 is in the table. which one ??

if mu is 1 then either 139 or 571 is in the table. Which one ??

I finally found the answer. Shame on standards being so unhelpful with hidden features. I found this on a keysight page:

"When RootSequenceIndex-r16 is enabled, the third and fourth column of Table 6.3.3.1-2 is used to decide the LRA value(s). When RootSequenceIndex-Rel16 is disabled, the second column of Table 6.3.3.1-1 and Table 6.3.3.1-2 are used to decide LRA.

Default: 139

Choices: 139, 571, 839, 1151"

This also adds another parameter at baseband apart from format which could have been just modified into the format list.