Why the begining balance is empty for the first period of the year ?

Hello,

I am working on Oracle Applications : 12.2.4 and I have a problem to get the begining balance amount in the trial balance.

I use the close process programs for income statement and balance sheet during the last period of my calendar (adjusting period). Then, as mentionned in the ledger close process, I reverse and post the balance sheet closing journals on the first period of the next year (adjusting period). So I can see amounts of the reverse journal in period activity column but the beginning balance is empty, including in the first non adjuting period.

Is there a way (parameter ?) to get the begining balance populated ?