A method performed at a central scheduler to schedule radio resources to users (740, 840) located in a plurality of cells (715, 815, 825) of a wireless network (700, 800), each cell (715, 815, 825) partially or wholly overlapping with at least one other cell (715, 815, 825) and/or being geographically adjacent to at least one other cell (715, 815, 825), the method comprising: for each cell (715, 815, 825), obtaining load related parameters of that cell (715, 815, 825), wherein for each cell (715, 815, 825), the load related parameters of that cell (715, 815, 825) comprise a minimum required load, a throughput distribution, and a throughput proportionality of that cell (715, 815, 825); for each cell pair among the plurality of cells (715, 815, 825), obtaining a coupling factor of that cell pair, wherein each cell pair comprises a cell x (715, 815, 825) and a cell y (715, 815, 825), and the corresponding coupling factor u xy couples an interference experienced at the cell x (715, 815, 825) due to usage of the radio resources scheduled for the users (740, 840) of the cell y (715, 815, 825); for each cell (715, 815, 825), allocating a free headroom to that cell (715, 815, 825) based on the load related parameters of the cells (715, 815, 825) and based on the coupling factors among the cells (715, 815, 825); and for each cell (715, 815, 825), notifying a local scheduler associated with that cell (715, 815, 825) of the free headroom allocated to that cell (715, 815, 825), wherein for each cell (715, 815, 825), the corresponding free headroom defines an amount of load headroom available for distribution among the users (740, 840) of that cell (715, 815, 825) when a local scheduler associated with that cell (715, 815, 825) schedules the radio resources to those users (740, 840), and wherein the free headrooms are allocated subject to a system stability of the wireless network (700, 800), the system stability being defined such that when the radio resources are scheduled to the users (740, 840) in accordance with the allocated headrooms, then for each cell (715, 815, 825), an interference experienced at that cell (715, 815, 825) due to usage of the scheduled radio resources does not exceed a maximum allowable interference at that cell (715, 815, 825). for each cell (715, 815, 825), obtaining load related parameters of that cell (715, 815, 825), wherein for each cell (715, 815, 825), the load related parameters of that cell (715, 815, 825) comprise a minimum required load, a throughput distribution, and a throughput proportionality of that cell (715, 815, 825); for each cell pair among the plurality of cells (715, 815, 825), obtaining a coupling factor of that cell pair, wherein each cell pair comprises a cell x (715, 815, 825) and a cell y (715, 815, 825), and the corresponding coupling factor u xy couples an interference experienced at the cell x (715, 815, 825) due to usage of the radio resources scheduled for the users (740, 840) of the cell y (715, 815, 825); for each cell (715, 815, 825), allocating a free headroom to that cell (715, 815, 825) based on the load related parameters of the cells (715, 815, 825) and based on the coupling factors among the cells (715, 815, 825); and for each cell (715, 815, 825), notifying a local scheduler associated with that cell (715, 815, 825) of the free headroom allocated to that cell (715, 815, 825), wherein for each cell (715, 815, 825), the corresponding free headroom defines an amount of load headroom available for distribution among the users (740, 840) of that cell (715, 815, 825) when a local scheduler associated with that cell (715, 815, 825) schedules the radio resources to those users (740, 840), and wherein the free headrooms are allocated subject to a system stability of the wireless network (700, 800), the system stability being defined such that when the radio resources are scheduled to the users (740, 840) in accordance with the allocated headrooms, then for each cell (715, 815, 825), an interference experienced at that cell (715, 815, 825) due to usage of the scheduled radio resources does not exceed a maximum allowable interference at that cell (715, 815, 825).