Constant Value modification

[timedomain]

Hi Dears,

Have anyone had experience about changing "constant value" parameter. What are the pros and cons.

Thanks

[chefo]

Constant Value or CV is used in the calculation of the initial UE TX Power during the RACH preamble transmission:

UETXPwr_init = PL + RTWP + CV, where PL is the pathloss (PL = BSTXPWR_cpich - RSCP), RTWP and CV are being read from BCCH -> SIB7

By default CV is set to -20dB or close. From this equation you can see that reducing the CV will reduce the initial UE TX Power, this in the normal case will degrade your Successful RACH procedures, and will increase the RACH cycles. CV could be changed only in special cases, as for example Indoor cells, but after careful analysis of the link budget in both directions.