A method for adaptation of service periods for different Traffic Indication Map, TIM, groups in a radio network node of a communication network, the method comprising: - determining, by the radio network node, a traffic load of the radio network node, wherein said determining is based at least on an estimate of how many wireless devices and which of the wireless devices, in the communication network, for which the radio network node has buffered data; - scheduling, by the radio network node, based on the determined traffic load, at least a first transmission time instance for a first TIM beacon and a second transmission time instance for a second TIM beacon consecutive to the first transmission time instance, wherein the time period between the first transmission time instance and the second transmission time instance is a service period for a first TIM group associated with a first TIM group identity in TIM information of the first TIM beacon, wherein the first TIM beacon only comprises the first TIM group identity, and the second TIM beacon comprises a second TIM group identity and the first TIM group identity, and wherein the first TIM group identity indicates the first TIM group of wireless devices and the second TIM group identity indicates a second TIM group of wireless devices; and - serving, by the radio network node, during a service period of a TIM beacon (101, 102), buffered data to a TIM group of wireless devices indicated in the respective TIM beacon (101, 102), wherein wireless devices, in the first TIM group of wireless devices, are served with data by the radio network node during the service period associated with the first TIM beacon and during a service period associated with the second TIM beacon comprising the first TIM group identity, wherein wireless devices, in the second TIM group of wireless devices, are served with data by the radio network node only during the service period associated with the second TIM beacon comprising the second TIM group identity, and wherein the scheduling comprises transmitting the first TIM beacon at the first transmission time instance and transmitting the second TIM beacon at the second transmission time instance. - determining, by the radio network node, a traffic load of the radio network node, wherein said determining is based at least on an estimate of how many wireless devices and which of the wireless devices, in the communication network, for which the radio network node has buffered data; - scheduling, by the radio network node, based on the determined traffic load, at least a first transmission time instance for a first TIM beacon and a second transmission time instance for a second TIM beacon consecutive to the first transmission time instance, wherein the time period between the first transmission time instance and the second transmission time instance is a service period for a first TIM group associated with a first TIM group identity in TIM information of the first TIM beacon, wherein the first TIM beacon only comprises the first TIM group identity, and the second TIM beacon comprises a second TIM group identity and the first TIM group identity, and wherein the first TIM group identity indicates the first TIM group of wireless devices and the second TIM group identity indicates a second TIM group of wireless devices; and - serving, by the radio network node, during a service period of a TIM beacon (101, 102), buffered data to a TIM group of wireless devices indicated in the respective TIM beacon (101, 102), wherein wireless devices, in the first TIM group of wireless devices, are served with data by the radio network node during the service period associated with the first TIM beacon and during a service period associated with the second TIM beacon comprising the first TIM group identity, wherein wireless devices, in the second TIM group of wireless devices, are served with data by the radio network node only during the service period associated with the second TIM beacon comprising the second TIM group identity, and wherein the scheduling comprises transmitting the first TIM beacon at the first transmission time instance and transmitting the second TIM beacon at the second transmission time instance.