A method and apparatus for power-based radio resource management in wireless radio systems based on continuously measuring a total interference power/.sub.tot and own-cell interference power/.sub.own as well as a continuously estimating the system noise power P.sub.N and/or the other-to-own cell interference ratio i based on these measurements. As a result, improved values P.sub.N and i are provided and a more accurate load factor/noise rise calculation can be performed.