A token bucket flow rate limiter is provided for a data transmission, comprising a token counter configured to be incremented at a rate determining the average flow rate of the transmission; a frequency divider connected to control incrementing of the token counter from a clock, the divider having an integer division factor; and a modulator configured to alternate the division factor between two different integers so as to make the resulting average flow rate tend to a programmed flow rate comprised between two boundary flow rates respectively corresponding to the two integers.