The interest rate of a bond is the nominal interest, projected to the nominal value and paid on prespecified future dates.
In case of fixed interest rate bonds, the interest rate does not change until maturity.
Buyers usually prefer bonds with higher frequency of interest payments, simply because payments are received more often.
In terms of frequency, US bonds generally pay interests semi-annually.
This frequency is only used rarely, only in special cases.
Fixed coupon bonds usually pay interests semi-annually.
In case of annual coupon payments, the interest for the whole year is received yearly, on a prespecified date.