when i am studying bank management6002 in sydney, some problems i cannot understand..

wheni draw up cashflow ladder to calculate pvbp, the bank balance sheet also showscall deposits and overdrafts with their current rate %pa. information also shows the zero coupon rate and par rate fortime bucket of "call", then 6 months, one year and so on. i do not know how to deal with these call deposit or overdrafts. shouldi putthem in one time bucket of "call"? buthow to calcutate the cashflow? the value times current rates then divided by frequency, but what is the frequency? can u tell me in detail how to deal with them in time bucket or just ignore them? thank u