The invention relates to an arrangement (130) in a radio base station (10) for handling data traffic within a cell of the radio base station (10), which radio base station (10) is comprised in a telecommunications network. The arrangement comprises a determining unit (131) arranged to determine a maximum power, which maximum power indicates available power to radio base station (10). In addition, the arrangement comprises a comparing unit (132) arranged to compare the maximum power to a threshold power value, and a handling unit (133) arranged to handle data traffic served by the radio base station (10) according to a shaper rule when the maximum power is below the first threshold power value. The shaper rule is defined to handle data traffic in such a way that an amount of data traffic transmitted over a time period is reduced consuming less power of the radio base station (10) than if the data traffic is handled according to a basic rule when the maximum power is above the threshold power value.