A method in a network node (102, 202, 302), comprising: scheduling a first data transmission for a first user equipment, UE (104, 204, 304), in a first transmission tier, the first transmission tier being in a first time-frequency resource and having predefined modulation and coding; scheduling a second data transmission for a second UE (104, 204, 304) in a second transmission tier, the second transmission tier having adaptive modulation and coding adapted based on channel quality indicator, CQI, feedback information, the second transmission tier being in a second time-frequency resource that at least partially overlaps the first time-frequency resource; transmitting the first data transmission in the first transmission tier according to the scheduling for the first UE (104, 204, 304); transmitting the second data transmission in the second transmission tier according to the scheduling for the second UE (104, 204, 304); the first transmission tier comprises a plurality of zones of time-frequency resources (501-504, 601-604), each zone having an associated set of first transmission tier transmission parameters; scheduling the first data transmission for the first UE (104, 204, 304) in the first transmission tier comprises scheduling the first data transmission for the first UE (104, 204, 304) in a zone of the plurality of zones; and transmitting the first data transmission in the first transmission tier comprises transmitting the first data transmission in the zone in accordance with the first transmission tier parameter set associated with the zone; wherein, for each zone, the associated set of first transmission tier transmission parameters comprises at least one of: a predefined modulation and coding scheme used in the zone; a power sharing factor α zone, where a ratio of a first transmission power level in the zone, in the first transmission tier, to a total transmission power level in the zone is given by α zone and a ratio of a second transmission power level in the zone, in the second transmission tier, to the total transmission power level in the zone is given by 1 - α zone, where the total transmission power level is shared between the two transmission tiers by the network node (102, 202, 302); and a number of layers multiplexed in the zone in at least one of: a time domain, a frequency domain, a code domain, a power domain, and a space domain. scheduling a first data transmission for a first user equipment, UE (104, 204, 304), in a first transmission tier, the first transmission tier being in a first time-frequency resource and having predefined modulation and coding; scheduling a second data transmission for a second UE (104, 204, 304) in a second transmission tier, the second transmission tier having adaptive modulation and coding adapted based on channel quality indicator, CQI, feedback information, the second transmission tier being in a second time-frequency resource that at least partially overlaps the first time-frequency resource; transmitting the first data transmission in the first transmission tier according to the scheduling for the first UE (104, 204, 304); transmitting the second data transmission in the second transmission tier according to the scheduling for the second UE (104, 204, 304); the first transmission tier comprises a plurality of zones of time-frequency resources (501-504, 601-604), each zone having an associated set of first transmission tier transmission parameters; scheduling the first data transmission for the first UE (104, 204, 304) in the first transmission tier comprises scheduling the first data transmission for the first UE (104, 204, 304) in a zone of the plurality of zones; and transmitting the first data transmission in the first transmission tier comprises transmitting the first data transmission in the zone in accordance with the first transmission tier parameter set associated with the zone; wherein, for each zone, the associated set of first transmission tier transmission parameters comprises at least one of: a predefined modulation and coding scheme used in the zone; a power sharing factor α zone, where a ratio of a first transmission power level in the zone, in the first transmission tier, to a total transmission power level in the zone is given by α zone and a ratio of a second transmission power level in the zone, in the second transmission tier, to the total transmission power level in the zone is given by 1 - α zone, where the total transmission power level is shared between the two transmission tiers by the network node (102, 202, 302); and a number of layers multiplexed in the zone in at least one of: a time domain, a frequency domain, a code domain, a power domain, and a space domain. a predefined modulation and coding scheme used in the zone; a power sharing factor α zone, where a ratio of a first transmission power level in the zone, in the first transmission tier, to a total transmission power level in the zone is given by α zone and a ratio of a second transmission power level in the zone, in the second transmission tier, to the total transmission power level in the zone is given by 1 - α zone, where the total transmission power level is shared between the two transmission tiers by the network node (102, 202, 302); and a number of layers multiplexed in the zone in at least one of: a time domain, a frequency domain, a code domain, a power domain, and a space domain.